SEC Info  
    Home      Search      My Interests      Help      Sign In      Please Sign In

Black Hills Power Inc – ‘10-Q’ for 9/30/19 – ‘JSON’

On:  Tuesday, 11/5/19, at 2:13pm ET   ·   For:  9/30/19   ·   Accession #:  12400-19-12   ·   File #:  1-07978

Previous ‘10-Q’:  ‘10-Q’ on 8/6/19 for 6/30/19   ·   Next:  ‘10-Q’ on 5/5/20 for 3/31/20   ·   Latest:  ‘10-Q’ on 11/3/20 for 9/30/20

Find Words in Filings emoji
 
  in    Show  and   Hints

  As Of               Filer                 Filing    For·On·As Docs:Size

11/05/19  Black Hills Power Inc             10-Q        9/30/19   57:4.7M

Quarterly Report   —   Form 10-Q   —   Sect. 13 / 15(d) – SEA’34
Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-Q        Quarterly Report                                    HTML    651K 
 2: EX-31.1     Certification -- §302 - SOA'02                      HTML     25K 
 3: EX-31.2     Certification -- §302 - SOA'02                      HTML     25K 
 4: EX-32.1     Certification -- §906 - SOA'02                      HTML     20K 
 5: EX-32.2     Certification -- §906 - SOA'02                      HTML     20K 
37: R1          Document and Entity Information Document            HTML     65K 
20: R2          Condensed Statements of Comprehensive Income        HTML     75K 
27: R3          Condensed Statements of Comprehensive Income        HTML     23K 
                (Parenthetical)                                                  
51: R4          Condensed Balance Sheets                            HTML    125K 
34: R5          Condensed Balance Sheets (Parenthetical)            HTML     23K 
17: R6          Condensed Statements of Cash Flows                  HTML     80K 
24: R7          Condensed Statements of Common Stockholder's        HTML     60K 
                Equity                                                           
54: R8          Management's Statement                              HTML     28K 
32: R9          Revenue                                             HTML     49K 
15: R10         Accounts Receivable                                 HTML     29K 
23: R11         Regulatory Accounting                               HTML     57K 
57: R12         Related-Party Transactions                          HTML     75K 
39: R13         Employee Benefit Plans                              HTML     69K 
14: R14         Fair Value of Financial Instruments                 HTML     27K 
22: R15         Supplemental Disclosure of Cash Flow Information    HTML     29K 
56: R16         Commitment and Contingencies                        HTML     19K 
38: R17         Leases                                              HTML     54K 
16: R18         Management's Statement (Policies)                   HTML     55K 
21: R19         Revenue (Tables)                                    HTML     45K 
49: R20         Accounts Receivable (Tables)                        HTML     26K 
41: R21         Regulatory Accounting (Tables)                      HTML     73K 
12: R22         Related-Party Transactions (Tables)                 HTML     78K 
29: R23         Employee Benefit Plans (Tables)                     HTML     71K 
47: R24         Fair Value of Financial Instruments (Tables)        HTML     26K 
40: R25         Supplemental Disclosure of Cash Flow Information    HTML     28K 
                (Tables)                                                         
11: R26         Leases (Tables)                                     HTML     61K 
28: R27         Management Statement (Details)                      HTML     20K 
46: R28         Revenue (Details)                                   HTML     38K 
42: R29         Accounts Receivable (Details)                       HTML     27K 
35: R30         Regulatory Accounting: Regulatory Assets (Details)  HTML     41K 
52: R31         Regulatory Accounting: Regulatory Liabilities       HTML     34K 
                (Details)                                                        
25: R32         Regulatory Accounting: Rate Review (Details)        HTML     37K 
18: R33         Related-Party Transactions (Details)                HTML     89K 
36: R34         Employee Benefit Plans (Details)                    HTML     58K 
53: R35         Fair Value of Financial Instruments (Details)       HTML     26K 
26: R36         Supplemental Disclosure of Cash Flow Information    HTML     35K 
                (Details)                                                        
19: R37         Leases (Details)                                    HTML     21K 
33: R38         Leases: Lease Costs (Details)                       HTML     23K 
55: R39         Leases: Supplemental Balance Sheet Information      HTML     24K 
                (Details)                                                        
45: R40         Leases: Supplemental Cash Flow Information          HTML     21K 
                (Details)                                                        
50: R41         Leases: Weighted Average Information (Details)      HTML     21K 
30: R42         Leases: Future Minimum Payments (Details)           HTML     36K 
48: XML         IDEA XML File -- Filing Summary                      XML     95K 
43: XML         XBRL Instance -- bhp10qq32019_htm                    XML   1.22M 
44: EXCEL       IDEA Workbook of Financial Reports                  XLSX     45K 
 7: EX-101.CAL  XBRL Calculations -- bkh-20190930_cal                XML    162K 
 8: EX-101.DEF  XBRL Definitions -- bkh-20190930_def                 XML    240K 
 9: EX-101.LAB  XBRL Labels -- bkh-20190930_lab                      XML    943K 
10: EX-101.PRE  XBRL Presentations -- bkh-20190930_pre               XML    495K 
 6: EX-101.SCH  XBRL Schema -- bkh-20190930                          XSD    102K 
31: JSON        XBRL Instance as JSON Data -- MetaLinks              212±   305K 
13: ZIP         XBRL Zipped Folder -- 0000012400-19-000012-xbrl      Zip    153K 


‘JSON’   —   XBRL Instance as JSON Data — MetaLinks


This File is an XBRL Instance as JavaScript Object Notation (JSON) Data.



{
"instance":  {
    "bhp10qq32019.htm":  {
        "axisCustom":  0,
        "axisStandard":  15,
        "contextCount":  183,
        "dts":  {
            "calculationLink":  {
                "local":  [
                    "bkh-20190930_cal.xml"
                    ]
                },
            "definitionLink":  {
                "local":  [
                    "bkh-20190930_def.xml"
                    ],
                "remote":  [
                    "http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-eedm-def-2018-01-31.xml",
                    "http://xbrl.fasb.org/srt/2018/elts/srt-eedm1-def-2018-01-31.xml"
                    ]
                },
            "inline":  {
                "local":  [
                    "bhp10qq32019.htm"
                    ]
                },
            "labelLink":  {
                "local":  [
                    "bkh-20190930_lab.xml"
                    ],
                "remote":  [
                    "http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-doc-2018-01-31.xml",
                    "https://xbrl.sec.gov/dei/2019/dei-doc-2019-01-31.xml"
                    ]
                },
            "presentationLink":  {
                "local":  [
                    "bkh-20190930_pre.xml"
                    ]
                },
            "referenceLink":  {
                "remote":  [
                    "http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-ref-2018-01-31.xml",
                    "https://xbrl.sec.gov/dei/2019/dei-ref-2019-01-31.xml"
                    ]
                },
            "schema":  {
                "local":  [
                    "bkh-20190930.xsd"
                    ],
                "remote":  [
                    "http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd",
                    "http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd",
                    "http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd",
                    "http://www.xbrl.org/2003/xl-2003-12-31.xsd",
                    "http://www.xbrl.org/2003/xlink-2003-12-31.xsd",
                    "http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd",
                    "http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd",
                    "http://www.xbrl.org/2005/xbrldt-2005.xsd",
                    "http://www.xbrl.org/2006/ref-2006-02-27.xsd",
                    "http://xbrl.fasb.org/srt/2018/elts/srt-types-2018-01-31.xsd",
                    "http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd",
                    "http://xbrl.fasb.org/us-gaap/2018/elts/us-roles-2018-01-31.xsd",
                    "http://xbrl.fasb.org/srt/2018/elts/srt-roles-2018-01-31.xsd",
                    "http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd",
                    "http://xbrl.fasb.org/us-gaap/2018/elts/us-types-2018-01-31.xsd",
                    "http://www.xbrl.org/lrr/arcrole/factExplanatory-2009-12-16.xsd",
                    "http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd",
                    "http://www.xbrl.org/lrr/role/net-2009-12-16.xsd",
                    "http://xbrl.sec.gov/currency/2017/currency-2017-01-31.xsd",
                    "https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd",
                    "https://xbrl.sec.gov/exch/2018/exch-2018-01-31.xsd",
                    "http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd",
                    "http://xbrl.sec.gov/naics/2017/naics-2017-01-31.xsd",
                    "http://xbrl.sec.gov/sic/2011/sic-2011-01-31.xsd",
                    "https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd",
                    "http://www.xbrl.org/lrr/role/deprecated-2009-12-16.xsd",
                    "http://www.xbrl.org/lrr/role/reference-2009-12-16.xsd",
                    "http://xbrl.fasb.org/us-gaap/2018/elts/us-parts-codification-2018-01-31.xsd"
                    ]
                }
            },
        "elementCount":  325,
        "entityCount":  1,
        "hidden":  {
            "http://fasb.org/us-gaap/2018-01-31":  15,
            "http://xbrl.sec.gov/dei/2019-01-31":  5,
            "total":  20
            },
        "keyCustom":  16,
        "keyStandard":  243,
        "memberCustom":  29,
        "memberStandard":  21,
        "nsprefix":  "bkh",
        "nsuri":  "http://www.blackhillscorp.com/20190930",
        "report":  {
            "R1":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "dei:DocumentType",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "document",
                "isDefault":  "true",
                "longName":  "0001000 - Document - Document and Entity Information Document",
                "role":  "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument",
                "shortName":  "Document and Entity Information Document",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "dei:DocumentType",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R10":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2110100 - Disclosure - Accounts Receivable:",
                "role":  "http://www.blackhillscorp.com/role/AccountsReceivable",
                "shortName":  "Accounts Receivable:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R11":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfRegulatoryAssetsAndLiabilitiesTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2116100 - Disclosure - Regulatory Accounting:",
                "role":  "http://www.blackhillscorp.com/role/RegulatoryAccounting",
                "shortName":  "Regulatory Accounting:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfRegulatoryAssetsAndLiabilitiesTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R12":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:RelatedPartyTransactionsDisclosureTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2119100 - Disclosure - Related-Party Transactions:",
                "role":  "http://www.blackhillscorp.com/role/RelatedPartyTransactions",
                "shortName":  "Related-Party Transactions:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:RelatedPartyTransactionsDisclosureTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R13":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2128100 - Disclosure - Employee Benefit Plans:",
                "role":  "http://www.blackhillscorp.com/role/EmployeeBenefitPlans",
                "shortName":  "Employee Benefit Plans:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R14":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:FairValueDisclosuresTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2129100 - Disclosure - Fair Value of Financial Instruments:",
                "role":  "http://www.blackhillscorp.com/role/FairValueOfFinancialInstruments",
                "shortName":  "Fair Value of Financial Instruments:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:FairValueDisclosuresTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R15":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:CashFlowSupplementalDisclosuresTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2131100 - Disclosure - Supplemental Disclosure of Cash Flow Information:",
                "role":  "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformation",
                "shortName":  "Supplemental Disclosure of Cash Flow Information:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:CashFlowSupplementalDisclosuresTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R16":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2132100 - Disclosure - Commitment and Contingencies:",
                "role":  "http://www.blackhillscorp.com/role/CommitmentAndContingencies",
                "shortName":  "Commitment and Contingencies:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R17":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:LesseeOperatingLeasesTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2133100 - Disclosure - Leases:",
                "role":  "http://www.blackhillscorp.com/role/Leases",
                "shortName":  "Leases:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "td",
                        "tr",
                        "table",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:LesseeOperatingLeasesTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R18":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2201201 - Disclosure - Management's Statement (Policies)",
                "role":  "http://www.blackhillscorp.com/role/ManagementsStatementPolicies",
                "shortName":  "Management's Statement (Policies)",
                "subGroupType":  "policies",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R19":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "ix:continuation",
                        "us-gaap:RevenueRecognitionPolicyTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:DisaggregationOfRevenueTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2307301 - Disclosure - Revenue (Tables)",
                "role":  "http://www.blackhillscorp.com/role/RevenueTables",
                "shortName":  "Revenue (Tables)",
                "subGroupType":  "tables",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "ix:continuation",
                        "us-gaap:RevenueRecognitionPolicyTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:DisaggregationOfRevenueTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R2":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:DisaggregationOfRevenueTableTextBlock",
                        "ix:continuation",
                        "us-gaap:RevenueRecognitionPolicyTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3QTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:Revenues",
                    "reportCount":  1,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "statement",
                "isDefault":  "false",
                "longName":  "1001000 - Statement - Condensed Statements of Comprehensive Income",
                "role":  "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome",
                "shortName":  "Condensed Statements of Comprehensive Income",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3QTD",
                    "decimals":  "-3",
                    "lang":  null,
                    "name":  "bkh:FuelAndPurchasedPower",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R20":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2310301 - Disclosure - Accounts Receivable (Tables)",
                "role":  "http://www.blackhillscorp.com/role/AccountsReceivableTables",
                "shortName":  "Accounts Receivable (Tables)",
                "subGroupType":  "tables",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R21":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfRegulatoryAssetsTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2316301 - Disclosure - Regulatory Accounting (Tables)",
                "role":  "http://www.blackhillscorp.com/role/RegulatoryAccountingTables",
                "shortName":  "Regulatory Accounting (Tables)",
                "subGroupType":  "tables",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfRegulatoryAssetsTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R22":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "div",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "bkh:ScheduleOfRelatedPartyAccountsReceivableAndPayableTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2319301 - Disclosure - Related-Party Transactions (Tables)",
                "role":  "http://www.blackhillscorp.com/role/RelatedPartyTransactionsTables",
                "shortName":  "Related-Party Transactions (Tables)",
                "subGroupType":  "tables",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "div",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "bkh:ScheduleOfRelatedPartyAccountsReceivableAndPayableTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R23":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2328301 - Disclosure - Employee Benefit Plans (Tables)",
                "role":  "http://www.blackhillscorp.com/role/EmployeeBenefitPlansTables",
                "shortName":  "Employee Benefit Plans (Tables)",
                "subGroupType":  "tables",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R24":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2329301 - Disclosure - Fair Value of Financial Instruments (Tables)",
                "role":  "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsTables",
                "shortName":  "Fair Value of Financial Instruments (Tables)",
                "subGroupType":  "tables",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R25":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2331301 - Disclosure - Supplemental Disclosure of Cash Flow Information (Tables)",
                "role":  "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationTables",
                "shortName":  "Supplemental Disclosure of Cash Flow Information (Tables)",
                "subGroupType":  "tables",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R26":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:LeaseCostTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2333301 - Disclosure - Leases (Tables)",
                "role":  "http://www.blackhillscorp.com/role/LeasesTables",
                "shortName":  "Leases (Tables)",
                "subGroupType":  "tables",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:LeaseCostTableTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R27":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "bkh:LesseeSupplementalBalanceSheetInformationRelatedtoLeasesTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:OperatingLeaseRightOfUseAsset",
                    "reportCount":  1,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2401402 - Disclosure - Management Statement (Details)",
                "role":  "http://www.blackhillscorp.com/role/ManagementStatementDetails",
                "shortName":  "Management Statement (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  null
                },
            "R28":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:DisaggregationOfRevenueTableTextBlock",
                        "ix:continuation",
                        "us-gaap:RevenueRecognitionPolicyTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3QTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2407402 - Disclosure - Revenue (Details)",
                "role":  "http://www.blackhillscorp.com/role/RevenueDetails",
                "shortName":  "Revenue (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:DisaggregationOfRevenueTableTextBlock",
                        "ix:continuation",
                        "us-gaap:RevenueRecognitionPolicyTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3QTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R29":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "ix:continuation",
                        "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:AccountsReceivableGrossCurrent",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2410402 - Disclosure - Accounts Receivable (Details)",
                "role":  "http://www.blackhillscorp.com/role/AccountsReceivableDetails",
                "shortName":  "Accounts Receivable (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "ix:continuation",
                        "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:AccountsReceivableGrossCurrent",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R3":  {
                "firstAnchor":  null,
                "groupType":  "statement",
                "isDefault":  "false",
                "longName":  "1001001 - Statement - Condensed Statements of Comprehensive Income (Parenthetical)",
                "role":  "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncomeParenthetical",
                "shortName":  "Condensed Statements of Comprehensive Income (Parenthetical)",
                "subGroupType":  "parenthetical",
                "uniqueAnchor":  null
                },
            "R30":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:ScheduleOfRegulatoryAssetsTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:RegulatoryAssets",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2416402 - Disclosure - Regulatory Accounting:  Regulatory Assets (Details)",
                "role":  "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails",
                "shortName":  "Regulatory Accounting:  Regulatory Assets (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:ScheduleOfRegulatoryAssetsTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:RegulatoryAssets",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R31":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:ScheduleOfRegulatoryLiabilitiesTextBlock",
                        "us-gaap:ScheduleOfRegulatoryAssetsTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:RegulatoryLiabilities",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2416403 - Disclosure - Regulatory Accounting:  Regulatory Liabilities (Details)",
                "role":  "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails",
                "shortName":  "Regulatory Accounting:  Regulatory Liabilities (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:ScheduleOfRegulatoryLiabilitiesTextBlock",
                        "us-gaap:ScheduleOfRegulatoryAssetsTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:RegulatoryLiabilities",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R32":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3_dei_LegalEntityAxis_bkh_SouthDakotaElectricandWyomingElectricMember_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_bkh_CorriedaleWindProjectMember_us-gaap_RegulatoryAgencyAxis_bkh_WyomingPublicServiceCommissionWPSCandSouthDakotaPublicUtilitiesCommissionSDPUCMember",
                    "decimals":  "-6",
                    "first":  true,
                    "lang":  null,
                    "name":  "bkh:PublicUtilitiesPropertyPlantandEquipmentCostOfPlantInvestment",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2416404 - Disclosure - Regulatory Accounting:  Rate Review (Details)",
                "role":  "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails",
                "shortName":  "Regulatory Accounting:  Rate Review (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3_dei_LegalEntityAxis_bkh_SouthDakotaElectricandWyomingElectricMember_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_bkh_CorriedaleWindProjectMember_us-gaap_RegulatoryAgencyAxis_bkh_WyomingPublicServiceCommissionWPSCandSouthDakotaPublicUtilitiesCommissionSDPUCMember",
                    "decimals":  "-6",
                    "first":  true,
                    "lang":  null,
                    "name":  "bkh:PublicUtilitiesPropertyPlantandEquipmentCostOfPlantInvestment",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R33":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2018Q3QTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "bkh:NonCashDividendsDistributedToParentBySubsidiaries",
                    "reportCount":  1,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2419402 - Disclosure - Related-Party Transactions (Details)",
                "role":  "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails",
                "shortName":  "Related-Party Transactions (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_us-gaap_ParentMember",
                    "decimals":  "INF",
                    "lang":  null,
                    "name":  "us-gaap:LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "ratio",
                    "xsiNil":  "false"
                    }
                },
            "R34":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "ix:continuation",
                        "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3QTD_us-gaap_RetirementPlanTypeAxis_us-gaap_PensionPlansDefinedBenefitMember",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:DefinedBenefitPlanServiceCost",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2428402 - Disclosure - Employee Benefit Plans (Details)",
                "role":  "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails",
                "shortName":  "Employee Benefit Plans (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "ix:continuation",
                        "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3QTD_us-gaap_RetirementPlanTypeAxis_us-gaap_PensionPlansDefinedBenefitMember",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:DefinedBenefitPlanServiceCost",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R35":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "ix:continuation",
                        "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3_us-gaap_FairValueByMeasurementBasisAxis_us-gaap_CarryingReportedAmountFairValueDisclosureMember",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:LongTermDebt",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2429402 - Disclosure - Fair Value of Financial Instruments (Details)",
                "role":  "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails",
                "shortName":  "Fair Value of Financial Instruments (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "ix:continuation",
                        "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3_us-gaap_FairValueByMeasurementBasisAxis_us-gaap_CarryingReportedAmountFairValueDisclosureMember",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:LongTermDebt",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R36":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "ix:continuation",
                        "us-gaap:ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:CapitalExpendituresIncurredButNotYetPaid",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2431402 - Disclosure - Supplemental Disclosure of Cash Flow Information (Details)",
                "role":  "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails",
                "shortName":  "Supplemental Disclosure of Cash Flow Information (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "ix:continuation",
                        "us-gaap:ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:CapitalExpendituresIncurredButNotYetPaid",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R37":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3_srt_RangeAxis_srt_MinimumMember",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:LesseeOperatingLeaseTermOfContract",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2433402 - Disclosure - Leases (Details)",
                "role":  "http://www.blackhillscorp.com/role/LeasesDetails",
                "shortName":  "Leases (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3_srt_RangeAxis_srt_MinimumMember",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:LesseeOperatingLeaseTermOfContract",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R38":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:LeaseCostTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3QTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:OperatingLeaseCost",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2433403 - Disclosure - Leases:  Lease Costs (Details)",
                "role":  "http://www.blackhillscorp.com/role/LeasesLeaseCostsDetails",
                "shortName":  "Leases:  Lease Costs (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:LeaseCostTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3QTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:OperatingLeaseCost",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R39":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "bkh:LesseeSupplementalBalanceSheetInformationRelatedtoLeasesTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:OperatingLeaseRightOfUseAsset",
                    "reportCount":  1,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2433404 - Disclosure - Leases:  Supplemental Balance Sheet Information (Details)",
                "role":  "http://www.blackhillscorp.com/role/LeasesSupplementalBalanceSheetInformationDetails",
                "shortName":  "Leases:  Supplemental Balance Sheet Information (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "bkh:LesseeSupplementalBalanceSheetInformationRelatedtoLeasesTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "lang":  null,
                    "name":  "us-gaap:OperatingLeaseLiabilityCurrent",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R4":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:CashAndCashEquivalentsAtCarryingValue",
                    "reportCount":  1,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "statement",
                "isDefault":  "false",
                "longName":  "1002000 - Statement - Condensed Balance Sheets",
                "role":  "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                "shortName":  "Condensed Balance Sheets",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "lang":  null,
                    "name":  "us-gaap:InventoryNet",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R40":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "bkh:LesseeSupplementalCashFlowInformationRelatedtoLeasesTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:OperatingLeasePayments",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2433405 - Disclosure - Leases:  Supplemental Cash Flow Information (Details)",
                "role":  "http://www.blackhillscorp.com/role/LeasesSupplementalCashFlowInformationDetails",
                "shortName":  "Leases:  Supplemental Cash Flow Information (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "bkh:LesseeSupplementalCashFlowInformationRelatedtoLeasesTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:OperatingLeasePayments",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R41":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "bkh:LesseeSupplementalWeightedAverageScheduleRelatedtoLeasesTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:OperatingLeaseWeightedAverageRemainingLeaseTerm1",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2433406 - Disclosure - Leases:  Weighted Average Information (Details)",
                "role":  "http://www.blackhillscorp.com/role/LeasesWeightedAverageInformationDetails",
                "shortName":  "Leases:  Weighted Average Information (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "bkh:LesseeSupplementalWeightedAverageScheduleRelatedtoLeasesTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:OperatingLeaseWeightedAverageRemainingLeaseTerm1",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R42":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2433407 - Disclosure - Leases:  Future Minimum Payments (Details)",
                "role":  "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails",
                "shortName":  "Leases:  Future Minimum Payments (Details)",
                "subGroupType":  "details",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
                        "ix:continuation",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2019Q3",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R5":  {
                "firstAnchor":  null,
                "groupType":  "statement",
                "isDefault":  "false",
                "longName":  "1002001 - Statement - Condensed Balance Sheets (Parenthetical)",
                "role":  "http://www.blackhillscorp.com/role/CondensedBalanceSheetsParenthetical",
                "shortName":  "Condensed Balance Sheets (Parenthetical)",
                "subGroupType":  "parenthetical",
                "uniqueAnchor":  null
                },
            "R6":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  "-3",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic",
                    "reportCount":  1,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    },
                "groupType":  "statement",
                "isDefault":  "false",
                "longName":  "1003000 - Statement - Condensed Statements of Cash Flows",
                "role":  "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows",
                "shortName":  "Condensed Statements of Cash Flows",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  "-3",
                    "lang":  null,
                    "name":  "us-gaap:UtilitiesOperatingExpenseDepreciationAndAmortization",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R7":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FI2017Q4_us-gaap_StatementEquityComponentsAxis_us-gaap_CommonStockMember",
                    "decimals":  "INF",
                    "first":  true,
                    "lang":  null,
                    "name":  "us-gaap:CommonStockSharesIssued",
                    "reportCount":  1,
                    "unitRef":  "shares",
                    "xsiNil":  "false"
                    },
                "groupType":  "statement",
                "isDefault":  "false",
                "longName":  "1004000 - Statement - Condensed Statements of Common Stockholder's Equity",
                "role":  "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity",
                "shortName":  "Condensed Statements of Common Stockholder's Equity",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "span",
                        "div",
                        "td",
                        "tr",
                        "table",
                        "div",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2018Q1QTD",
                    "decimals":  "-3",
                    "lang":  null,
                    "name":  "us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  "usd",
                    "xsiNil":  "false"
                    }
                },
            "R8":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2101100 - Disclosure - Management's Statement:",
                "role":  "http://www.blackhillscorp.com/role/ManagementsStatement",
                "shortName":  "Management's Statement:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                },
            "R9":  {
                "firstAnchor":  {
                    "ancestors":  [
                        "span",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:RevenueFromContractWithCustomerTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    },
                "groupType":  "disclosure",
                "isDefault":  "false",
                "longName":  "2107100 - Disclosure - Revenue:",
                "role":  "http://www.blackhillscorp.com/role/Revenue",
                "shortName":  "Revenue:",
                "subGroupType":  "",
                "uniqueAnchor":  {
                    "ancestors":  [
                        "span",
                        "div",
                        "body",
                        "html"
                        ],
                    "baseRef":  "bhp10qq32019.htm",
                    "contextRef":  "FD2019Q3YTD",
                    "decimals":  null,
                    "first":  true,
                    "lang":  "en-US",
                    "name":  "us-gaap:RevenueFromContractWithCustomerTextBlock",
                    "reportCount":  1,
                    "unique":  true,
                    "unitRef":  null,
                    "xsiNil":  "false"
                    }
                }
            },
        "segmentCount":  51,
        "tag":  {
            "bkh_AllocatedCostsFromRelatedPartiesMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Costs allocated from related parties included parent, subsidiaries of a common parent and other affiliated entities [Member]",
                            "label":  "Allocated Costs From Related Parties [Member]",
                            "terseLabel":  "Corporate support services and fees from Black Hills Service Company"
                            }
                        }
                    },
                "localname":  "AllocatedCostsFromRelatedPartiesMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_AllowanceForFundsUsedDuringConstructionMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The offsetting entry to other income when an enterprise capitalizes, as part of the cost of plant and equipment, the cost of financing construction as financed partially by equity.",
                            "label":  "Allowance For Funds Used During Construction [Member]",
                            "terseLabel":  "Deferred taxes on AFUDC"
                            }
                        }
                    },
                "localname":  "AllowanceForFundsUsedDuringConstructionMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_AmountofIncreasesoughtinGeneratingCapacityUnderEnvironmentalImprovementAdjustmentTariffMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of Increase sought in Generating Capacity Under Environmental Improvement Adjustment Tariff [Member]",
                            "label":  "Amount of Increase sought in Generating Capacity Under Environmental Improvement Adjustment Tariff [Member]",
                            "terseLabel":  "Amount of Increase sought in Generating Capacity Under Environmental Improvement Adjustment Tariff"
                            }
                        }
                    },
                "localname":  "AmountofIncreasesoughtinGeneratingCapacityUnderEnvironmentalImprovementAdjustmentTariffMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_CoalPurchasedMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Coal, Purchased [Member]",
                            "label":  "Coal, Purchased [Member]",
                            "terseLabel":  "Purchases of coal from WRDC"
                            }
                        }
                    },
                "localname":  "CoalPurchasedMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_CorriedaleWindProjectMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Corriedale Wind Project [Member]",
                            "label":  "Corriedale Wind Project [Member]",
                            "terseLabel":  "Corriedale Wind Project"
                            }
                        }
                    },
                "localname":  "CorriedaleWindProjectMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_CostOfRemovalMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Cost of removal [Member]",
                            "label":  "Cost Of Removal [Member]",
                            "terseLabel":  "Cost of removal for utility plant"
                            }
                        }
                    },
                "localname":  "CostOfRemovalMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_CustomerSubscriptionPeriodWasCompletedWithCustomerInterestFulfillingAllAvailableEnergyMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Customer Subscription Period Was Completed With Customer Interest Fulfilling All Available Energy [Member]",
                            "label":  "Customer Subscription Period Was Completed With Customer Interest Fulfilling All Available Energy [Member]",
                            "terseLabel":  "Customer Subscription Period Was Completed With Customer Interest Fulfilling All Available Energy"
                            }
                        }
                    },
                "localname":  "CustomerSubscriptionPeriodWasCompletedWithCustomerInterestFulfillingAllAvailableEnergyMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_DeferredIncomeTaxChargesaMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Rate Action of a regulator resulting in capitalization or accrual of income taxes",
                            "label":  "Deferred Income Tax Charges a [Member]",
                            "terseLabel":  "Excess deferred income taxes"
                            }
                        }
                    },
                "localname":  "DeferredIncomeTaxChargesaMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_EnergySoldToCheyenneLightMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Energy Sold To Cheyenne Light [Member]",
                            "label":  "Energy sold to Cheyenne Light [Member]",
                            "terseLabel":  "Energy sold to Cheyenne Light"
                            }
                        }
                    },
                "localname":  "EnergySoldToCheyenneLightMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_FlowThroughAccountingMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The income tax effects of certain tax items are reflected in cost of service for the customer in which the tax benefits are realized and result in lower utiity rates.  The regulatory treatment under flow-through accounting was applied for this tax benefit generated by utility costs that were previously capitalized for tax purposes in a rate case settlement and resulted in a lower rate increase.  A regulatory asset was established to reflect the future increase in taxes payable recovered from sutomers as the temporarty difference reverses.[Member]",
                            "label":  "Flow Through Accounting [Member]",
                            "terseLabel":  "Deferred taxes on flow through accounting"
                            }
                        }
                    },
                "localname":  "FlowThroughAccountingMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_FuelAndPurchasedPower":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_OperatingExpenses",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Fuel costs incurred that are directly related to energy produced and sold and services rendered during the reporting period, combined with the amount of purchased power charged against earnings for the period.",
                            "label":  "Fuel and Purchased Power",
                            "terseLabel":  "Fuel and purchased power"
                            }
                        }
                    },
                "localname":  "FuelAndPurchasedPower",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "bkh_GroundLeasewithWygenIIIMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Ground Lease with Wygen III [Member]",
                            "label":  "Ground Lease with Wygen III [Member]",
                            "terseLabel":  "Wygen III ground lease with WRDC"
                            }
                        }
                    },
                "localname":  "GroundLeasewithWygenIIIMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_HappyJackWindPurchasePowerAgreeementMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Happy Jack Wind Purchase Power Agreeement [Member]",
                            "label":  "Happy Jack Wind Purchase Power Agreeement [Member]",
                            "terseLabel":  "Purchase of renewable wind energy from Cheyenne Light - Happy Jack"
                            }
                        }
                    },
                "localname":  "HappyJackWindPurchasePowerAgreeementMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_HorizonPointSharedFacilityRevenuesMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Horizon Point Shared Facility Revenues [Member]",
                            "label":  "Horizon Point Shared Facility Revenues [Member]",
                            "terseLabel":  "Horizon Point shared facility revenues"
                            }
                        }
                    },
                "localname":  "HorizonPointSharedFacilityRevenuesMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_InterestPayableRelatedParty":  {
                "auth_ref":  [
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Interest Payable Related Party",
                            "label":  "Interest Payable Related Party",
                            "terseLabel":  "Interest Payable Related Party"
                            }
                        }
                    },
                "localname":  "InterestPayableRelatedParty",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "bkh_LesseeSupplementalBalanceSheetInformationRelatedtoLeasesTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Lessee Supplemental Balance Sheet Information Related to Leases [Table Text Block]",
                            "label":  "Lessee Supplemental Balance Sheet Information Related to Leases [Table Text Block]",
                            "terseLabel":  "Lessee Supplemental Balance Sheet Information Related to Leases"
                            }
                        }
                    },
                "localname":  "LesseeSupplementalBalanceSheetInformationRelatedtoLeasesTableTextBlock",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "bkh_LesseeSupplementalCashFlowInformationRelatedtoLeasesTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Lessee Supplemental Cash Flow Information Related to Leases [Table Text Block]",
                            "label":  "Lessee Supplemental Cash Flow Information Related to Leases [Table Text Block]",
                            "terseLabel":  "Lessee Supplemental Cash Flow Information Related to Leases"
                            }
                        }
                    },
                "localname":  "LesseeSupplementalCashFlowInformationRelatedtoLeasesTableTextBlock",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "bkh_LesseeSupplementalWeightedAverageScheduleRelatedtoLeasesTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Lessee Supplemental Weighted Average Schedule Related to Leases [Table Text Block]",
                            "label":  "Lessee Supplemental Weighted Average Schedule Related to Leases [Table Text Block]",
                            "terseLabel":  "Lessee Supplemental Weighted Average Schedule Related to Leases"
                            }
                        }
                    },
                "localname":  "LesseeSupplementalWeightedAverageScheduleRelatedtoLeasesTableTextBlock",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "bkh_NewTotalSoughtInGeneratingCapacityUnderEnvironmentalImprovementAdjustmentTariffMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "New Total Sought In Generating Capacity Under Environmental Improvement Adjustment Tariff [Member]",
                            "label":  "New Total Sought In Generating Capacity Under Environmental Improvement Adjustment Tariff [Member]",
                            "terseLabel":  "New Total Sought In Generating Capacity Under Environmental Improvement Adjustment Tariff"
                            }
                        }
                    },
                "localname":  "NewTotalSoughtInGeneratingCapacityUnderEnvironmentalImprovementAdjustmentTariffMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_NonCashDividendsDistributedToParentBySubsidiaries":  {
                "auth_ref":  [
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Non-cash Dividend Distributed to Parent by Subsidiaries",
                            "label":  "Non-cash Dividends Distributed to Parent by Subsidiaries",
                            "negatedLabel":  "Dividend to Parent company",
                            "terseLabel":  "Non-cash dividend to Parent"
                            }
                        }
                    },
                "localname":  "NonCashDividendsDistributedToParentBySubsidiaries",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity",
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails",
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "bkh_OtherRegulatoryAssetsMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Other regulatory assets [Member]",
                            "label":  "Other Regulatory Assets [Member]",
                            "verboseLabel":  "Other regulatory assets"
                            }
                        }
                    },
                "localname":  "OtherRegulatoryAssetsMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_OtherRegulatoryLiabilitiesMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Other regulatory liabilities [Member]",
                            "label":  "Other Regulatory Liabilities [Member]",
                            "terseLabel":  "Other regulatory liabilities"
                            }
                        }
                    },
                "localname":  "OtherRegulatoryLiabilitiesMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_PublicUtilitiesAllowanceForFundsUsedDuringConstructionBorrowedInterestCostsCapitalized":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_NonoperatingIncomeExpense",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The component of the allowance for funds used during construction during the period which represents the approximate composite costs of borrowed funds and is netted against interest expense.",
                            "label":  "Public Utilities Allowance For Funds Used During Construction Borrowed Interest Costs Capitalized",
                            "terseLabel":  "Allowance for funds used during construction - borrowed"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesAllowanceForFundsUsedDuringConstructionBorrowedInterestCostsCapitalized",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "bkh_PublicUtilitiesNumberofElectricUtilitiesJointlyOwningWindProject":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Public Utilities, Number of Electric Utilities Jointly Owning Wind Project",
                            "label":  "Public Utilities, Number of Electric Utilities Jointly Owning Wind Project",
                            "terseLabel":  "Public Utilities, Number of Electric Utilities Jointly Owning Wind Project"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesNumberofElectricUtilitiesJointlyOwningWindProject",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "integerItemType"
                },
            "bkh_PublicUtilitiesPropertyPlantandEquipmentCostOfPlantInvestment":  {
                "auth_ref":  [
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Public Utilities, Property, Plant and Equipment, Cost Of Plant Investment",
                            "label":  "Public Utilities, Property, Plant and Equipment, Cost Of Plant Investment",
                            "terseLabel":  "Public Utilities, Property, Plant and Equipment, Cost Of Plant Investment"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesPropertyPlantandEquipmentCostOfPlantInvestment",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "bkh_PurchaseOfExcessEnergyCheyenneLightMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Purchase of excess energy from Cheyenne Light [Member]",
                            "label":  "Purchase of Excess Energy, Cheyenne Light [Member]",
                            "terseLabel":  "Purchase of excess energy from Cheyenne Light"
                            }
                        }
                    },
                "localname":  "PurchaseOfExcessEnergyCheyenneLightMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_PurchaseOfNaturalGasCheyenneLightMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Purchase Of Natural Gas, Cheyenne Light [Member]",
                            "label":  "Purchase Of Natural Gas, Cheyenne Light [Member]",
                            "terseLabel":  "Gas transportation service agreement with Cheyenne Light for firm and interruptible gas transportation"
                            }
                        }
                    },
                "localname":  "PurchaseOfNaturalGasCheyenneLightMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_RegulatedUtilityMarketOffSystemSalesMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Regulated Utility Market Off-System Sales",
                            "label":  "Regulated Utility Market Off-System Sales [Member]",
                            "terseLabel":  "Market - off-system sales"
                            }
                        }
                    },
                "localname":  "RegulatedUtilityMarketOffSystemSalesMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_RegulatedUtilityRetailMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Regulated Utility Retail",
                            "label":  "Regulated Utility Retail [Member]",
                            "terseLabel":  "Retail"
                            }
                        }
                    },
                "localname":  "RegulatedUtilityRetailMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_RegulatedUtilityTransmissionMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Regulated Utility Transmission",
                            "label":  "Regulated Utility Transmission [Member]",
                            "terseLabel":  "Transmission/Other"
                            }
                        }
                    },
                "localname":  "RegulatedUtilityTransmissionMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_RegulatedUtilityWholesaleMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Regulated Utility Wholesale",
                            "label":  "Regulated Utility Wholesale [Member]",
                            "terseLabel":  "Wholesale"
                            }
                        }
                    },
                "localname":  "RegulatedUtilityWholesaleMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_ScheduleOfDefinedBenefitPlansContributionsTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Schedule of Defined Benefit Plans Contributions for the current year and specific future years.[Text Block]",
                            "label":  "Schedule of Defined Benefit Plans Contributions [Table Text Block]",
                            "terseLabel":  "Schedule of Defined Benefit Plans Contributions"
                            }
                        }
                    },
                "localname":  "ScheduleOfDefinedBenefitPlansContributionsTableTextBlock",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "bkh_ScheduleOfRelatedPartyAccountsReceivableAndPayableTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of accounts receivable at the gross carrying value for goods and services provided to a related party and disclosure of accounts payable at the gross carrying value for goods and services received from a related party. [Table Text Block]",
                            "label":  "Schedule of Related Party Accounts Receivable and Payable [Table Text Block]",
                            "terseLabel":  "Schedule of Related Party Accounts Receivable and Payable"
                            }
                        }
                    },
                "localname":  "ScheduleOfRelatedPartyAccountsReceivableAndPayableTableTextBlock",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "bkh_ScheduleOfRelatedPartyNotesTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of related party notes receivable and notes payable at the net carrying value. [Table Text Block]",
                            "label":  "Schedule of Related Party Notes [Table Text Block]",
                            "terseLabel":  "Schedule of Related Party Notes"
                            }
                        }
                    },
                "localname":  "ScheduleOfRelatedPartyNotesTableTextBlock",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "bkh_ScheduleOfRevenuesAndPurchasesFromRelatedPartiesTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of revenues earned from and purchases expensed from transactions with related parties. [Table Text Block]",
                            "label":  "Schedule of Revenues and Purchases from Related Parties [Table Text Block]",
                            "terseLabel":  "Schedule of Revenues and Purchases from Related Parties"
                            }
                        }
                    },
                "localname":  "ScheduleOfRevenuesAndPurchasesFromRelatedPartiesTableTextBlock",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "bkh_ScheduleofRelatedPartyInterestIncomeExpenseTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of interest income with related party and interest expense with a related party.",
                            "label":  "Schedule of Related Party Interest Income Expense [Table Text Block]",
                            "terseLabel":  "Schedule of Related Party Interest Income Expense"
                            }
                        }
                    },
                "localname":  "ScheduleofRelatedPartyInterestIncomeExpenseTableTextBlock",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "bkh_ScheduleofRelatedPartyNotesPayabletoParentCompanyTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "[Table Text Block] for Schedule of Related Party Notes Payable to Parent Company [Table]",
                            "label":  "Schedule of Related Party Notes Payable to Parent Company [Table Text Block]",
                            "terseLabel":  "Schedule of Related Party Notes Payable to Parent"
                            }
                        }
                    },
                "localname":  "ScheduleofRelatedPartyNotesPayabletoParentCompanyTableTextBlock",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "bkh_SilverSageWindPowerPurchaseAgreementMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Silver Sage Wind Power Purchase Agreement [Member]",
                            "label":  "Silver Sage Wind Power Purchase Agreement [Member]",
                            "terseLabel":  "Purchase of renewable wind energy from Cheyenne Light - Silver Sage"
                            }
                        }
                    },
                "localname":  "SilverSageWindPowerPurchaseAgreementMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_SouthDakotaElectricMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "South Dakota Electric [Member]",
                            "label":  "South Dakota Electric [Member]",
                            "terseLabel":  "South Dakota Electric"
                            }
                        }
                    },
                "localname":  "SouthDakotaElectricMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_SouthDakotaElectricandWyomingElectricMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "South Dakota Electric and Wyoming Electric [Member]",
                            "label":  "South Dakota Electric and Wyoming Electric [Member]",
                            "terseLabel":  "South Dakota Electric and Wyoming Electric"
                            }
                        }
                    },
                "localname":  "SouthDakotaElectricandWyomingElectricMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_SouthDakotaPublicUtilitiesCommissionSDPUCMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "South Dakota Public Utilities Commission (SDPUC) [Member]",
                            "label":  "South Dakota Public Utilities Commission (SDPUC) [Member]",
                            "terseLabel":  "South Dakota Public Utilities Commission (SDPUC)"
                            }
                        }
                    },
                "localname":  "SouthDakotaPublicUtilitiesCommissionSDPUCMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_SupplementalCashFlowInformationLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "[Line Items] for Supplemental Cash Flow Information [Table]",
                            "label":  "Supplemental Cash Flow Information [Line Items]",
                            "terseLabel":  "Supplemental Cash Flow Information [Line Items]"
                            }
                        }
                    },
                "localname":  "SupplementalCashFlowInformationLineItems",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "bkh_SupplementalCashFlowInformationTable":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Supplemental Cash Flow Information [Table]",
                            "label":  "Supplemental Cash Flow Information [Table]",
                            "terseLabel":  "Supplemental Cash Flow Information [Table]"
                            }
                        }
                    },
                "localname":  "SupplementalCashFlowInformationTable",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "bkh_UtilityMoneyPoolMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Utility Money Pool [Member]",
                            "label":  "Utility Money Pool [Member]",
                            "terseLabel":  "Utility Money Pool"
                            }
                        }
                    },
                "localname":  "UtilityMoneyPoolMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_UtilityPlantMegawattCapacity":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Utility Plant, Megawatt Capacity",
                            "label":  "Utility Plant, Megawatt Capacity",
                            "terseLabel":  "Utility Plant, Megawatt Capacity"
                            }
                        }
                    },
                "localname":  "UtilityPlantMegawattCapacity",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "powerItemType"
                },
            "bkh_VegetationManagementMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Vegetation Management [Member]",
                            "label":  "Vegetation Management [Member]",
                            "terseLabel":  "Vegetation management"
                            }
                        }
                    },
                "localname":  "VegetationManagementMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "bkh_WyomingPublicServiceCommissionWPSCandSouthDakotaPublicUtilitiesCommissionSDPUCMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Wyoming Public Service Commission (WPSC) and South Dakota Public Utilities Commission (SDPUC) [Member]",
                            "label":  "Wyoming Public Service Commission (WPSC) and South Dakota Public Utilities Commission (SDPUC) [Member]",
                            "terseLabel":  "Wyoming Public Service Commission (WPSC) and South Dakota Public Utilities Commission (SDPUC)"
                            }
                        }
                    },
                "localname":  "WyomingPublicServiceCommissionWPSCandSouthDakotaPublicUtilitiesCommissionSDPUCMember",
                "nsuri":  "http://www.blackhillscorp.com/20190930",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "dei_AmendmentFlag":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.",
                            "label":  "Amendment Flag",
                            "terseLabel":  "Amendment Flag"
                            }
                        }
                    },
                "localname":  "AmendmentFlag",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "booleanItemType"
                },
            "dei_CityAreaCode":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Area code of city",
                            "label":  "City Area Code",
                            "terseLabel":  "City Area Code"
                            }
                        }
                    },
                "localname":  "CityAreaCode",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_CoverAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Cover page.",
                            "label":  "Cover page."
                            }
                        }
                    },
                "localname":  "CoverAbstract",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "xbrltype":  "stringItemType"
                },
            "dei_CurrentFiscalYearEndDate":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "End date of current fiscal year in the format --MM-DD.",
                            "label":  "Current Fiscal Year End Date",
                            "terseLabel":  "Current Fiscal Year End Date"
                            }
                        }
                    },
                "localname":  "CurrentFiscalYearEndDate",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "gMonthDayItemType"
                },
            "dei_DocumentFiscalPeriodFocus":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Fiscal period values are FY, Q1, Q2, and Q3.  1st, 2nd and 3rd quarter 10-Q or 10-QT statements have value Q1, Q2, and Q3 respectively, with 10-K, 10-KT or other fiscal year statements having FY.",
                            "label":  "Document Fiscal Period Focus",
                            "terseLabel":  "Document Fiscal Period Focus"
                            }
                        }
                    },
                "localname":  "DocumentFiscalPeriodFocus",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "fiscalPeriodItemType"
                },
            "dei_DocumentFiscalYearFocus":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "This is focus fiscal year of the document report in CCYY format.  For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus.  Example: 2006.",
                            "label":  "Document Fiscal Year Focus",
                            "terseLabel":  "Document Fiscal Year Focus"
                            }
                        }
                    },
                "localname":  "DocumentFiscalYearFocus",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "gYearItemType"
                },
            "dei_DocumentPeriodEndDate":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The end date of the period reflected on the cover page if a periodic report.  For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented.  If there is no historical data in the report, use the filing date.  The format of the date is CCYY-MM-DD.",
                            "label":  "Document Period End Date",
                            "terseLabel":  "Document Period End Date"
                            }
                        }
                    },
                "localname":  "DocumentPeriodEndDate",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "dateItemType"
                },
            "dei_DocumentQuarterlyReport":  {
                "auth_ref":  [
                    "r227"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Boolean flag that is true only for a form used as an quarterly report.",
                            "label":  "Document Quarterly Report",
                            "terseLabel":  "Document Quarterly Report"
                            }
                        }
                    },
                "localname":  "DocumentQuarterlyReport",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "booleanItemType"
                },
            "dei_DocumentTransitionReport":  {
                "auth_ref":  [
                    "r228"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Boolean flag that is true only for a form used as a transition report.",
                            "label":  "Document Transition Report",
                            "terseLabel":  "Document Transition Report"
                            }
                        }
                    },
                "localname":  "DocumentTransitionReport",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "booleanItemType"
                },
            "dei_DocumentType":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc).  The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.",
                            "label":  "Document Type",
                            "terseLabel":  "Document Type"
                            }
                        }
                    },
                "localname":  "DocumentType",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "submissionTypeItemType"
                },
            "dei_EntityAddressAddressLine1":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Address Line 1 such as Attn, Building Name, Street Name",
                            "label":  "Entity Address, Address Line One",
                            "terseLabel":  "Entity Address, Address Line One"
                            }
                        }
                    },
                "localname":  "EntityAddressAddressLine1",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_EntityAddressCityOrTown":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Name of the City or Town",
                            "label":  "Entity Address, City or Town",
                            "terseLabel":  "Entity Address, City or Town"
                            }
                        }
                    },
                "localname":  "EntityAddressCityOrTown",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_EntityAddressPostalZipCode":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Code for the postal or zip code",
                            "label":  "Entity Address, Postal Zip Code",
                            "terseLabel":  "Entity Address, Postal Zip Code"
                            }
                        }
                    },
                "localname":  "EntityAddressPostalZipCode",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_EntityAddressStateOrProvince":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Name of the state or province.",
                            "label":  "Entity Address, State or Province",
                            "terseLabel":  "Entity Address, State or Province"
                            }
                        }
                    },
                "localname":  "EntityAddressStateOrProvince",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "stateOrProvinceItemType"
                },
            "dei_EntityCentralIndexKey":  {
                "auth_ref":  [
                    "r229"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC.  It is commonly abbreviated as CIK.",
                            "label":  "Entity Central Index Key",
                            "terseLabel":  "Entity Central Index Key"
                            }
                        }
                    },
                "localname":  "EntityCentralIndexKey",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "centralIndexKeyItemType"
                },
            "dei_EntityCommonStockSharesOutstanding":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report.  Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument.",
                            "label":  "Entity Common Stock, Shares Outstanding",
                            "terseLabel":  "Entity Common Stock, Shares Outstanding"
                            }
                        }
                    },
                "localname":  "EntityCommonStockSharesOutstanding",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "sharesItemType"
                },
            "dei_EntityCurrentReportingStatus":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Indicate 'Yes' or 'No' whether registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days.  This information should be based on the registrant's current or most recent filing containing the related disclosure.",
                            "label":  "Entity Current Reporting Status",
                            "terseLabel":  "Entity Current Reporting Status"
                            }
                        }
                    },
                "localname":  "EntityCurrentReportingStatus",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "yesNoItemType"
                },
            "dei_EntityDomain":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "All the names of the entities being reported upon in a document.  Any legal structure used to conduct activities or to hold assets.  Some examples of such structures are corporations, partnerships, limited liability companies, grantor trusts, and other trusts.  This item does not include business and geographical segments which are included in the geographical or business segments domains.",
                            "label":  "Entity [Domain]",
                            "terseLabel":  "Entity [Domain]"
                            }
                        }
                    },
                "localname":  "EntityDomain",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "dei_EntityEmergingGrowthCompany":  {
                "auth_ref":  [
                    "r229"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Indicate if registrant meets the emerging growth company criteria.",
                            "label":  "Entity Emerging Growth Company",
                            "terseLabel":  "Entity Emerging Growth Company"
                            }
                        }
                    },
                "localname":  "EntityEmergingGrowthCompany",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "booleanItemType"
                },
            "dei_EntityFileNumber":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Commission file number.  The field allows up to 17 characters.  The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.",
                            "label":  "Entity File Number",
                            "terseLabel":  "Entity File Number"
                            }
                        }
                    },
                "localname":  "EntityFileNumber",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "fileNumberItemType"
                },
            "dei_EntityFilerCategory":  {
                "auth_ref":  [
                    "r229"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Indicate whether the registrant is one of the following:  Large Accelerated Filer, Accelerated Filer, Non-accelerated Filer.  Definitions of these categories are stated in Rule 12b-2 of the Exchange Act.  This information should be based on the registrant's current or most recent filing containing the related disclosure.",
                            "label":  "Entity Filer Category",
                            "terseLabel":  "Entity Filer Category"
                            }
                        }
                    },
                "localname":  "EntityFilerCategory",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "filerCategoryItemType"
                },
            "dei_EntityIncorporationStateCountryCode":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Two-character EDGAR code representing the state or country of incorporation.",
                            "label":  "Entity Incorporation, State or Country Code",
                            "terseLabel":  "Entity Incorporation, State or Country Code"
                            }
                        }
                    },
                "localname":  "EntityIncorporationStateCountryCode",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "edgarStateCountryItemType"
                },
            "dei_EntityInteractiveDataCurrent":  {
                "auth_ref":  [
                    "r230"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Boolean flag that is true when the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).",
                            "label":  "Entity Interactive Data Current",
                            "terseLabel":  "Entity Interactive Data Current"
                            }
                        }
                    },
                "localname":  "EntityInteractiveDataCurrent",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "yesNoItemType"
                },
            "dei_EntityRegistrantName":  {
                "auth_ref":  [
                    "r229"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.",
                            "label":  "Entity Registrant Name",
                            "terseLabel":  "Entity Registrant Name"
                            }
                        }
                    },
                "localname":  "EntityRegistrantName",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_EntityShellCompany":  {
                "auth_ref":  [
                    "r229"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Boolean flag that is true when the registrant is a shell company as defined in Rule 12b-2 of the Exchange Act.",
                            "label":  "Entity Shell Company",
                            "terseLabel":  "Entity Shell Company"
                            }
                        }
                    },
                "localname":  "EntityShellCompany",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "booleanItemType"
                },
            "dei_EntitySmallBusiness":  {
                "auth_ref":  [
                    "r229"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Indicates that the company is a Smaller Reporting Company (SRC).",
                            "label":  "Entity Small Business",
                            "terseLabel":  "Entity Small Business"
                            }
                        }
                    },
                "localname":  "EntitySmallBusiness",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "booleanItemType"
                },
            "dei_EntityTaxIdentificationNumber":  {
                "auth_ref":  [
                    "r229"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.",
                            "label":  "Entity Tax Identification Number",
                            "terseLabel":  "Entity Tax Identification Number"
                            }
                        }
                    },
                "localname":  "EntityTaxIdentificationNumber",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "employerIdItemType"
                },
            "dei_LegalEntityAxis":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The set of legal entities associated with a report.",
                            "label":  "Legal Entity [Axis]",
                            "terseLabel":  "Legal Entity [Axis]"
                            }
                        }
                    },
                "localname":  "LegalEntityAxis",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "dei_LocalPhoneNumber":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Local phone number for entity.",
                            "label":  "Local Phone Number",
                            "terseLabel":  "Local Phone Number"
                            }
                        }
                    },
                "localname":  "LocalPhoneNumber",
                "nsuri":  "http://xbrl.sec.gov/dei/2019-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/DocumentAndEntityInformationDocument"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "srt_MajorCustomersAxis":  {
                "auth_ref":  [
                    "r89",
                    "r103",
                    "r105"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Customer [Axis]",
                            "terseLabel":  "Customer [Axis]"
                            }
                        }
                    },
                "localname":  "MajorCustomersAxis",
                "nsuri":  "http://fasb.org/srt/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "srt_MaximumMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Maximum [Member]",
                            "terseLabel":  "Maximum"
                            }
                        }
                    },
                "localname":  "MaximumMember",
                "nsuri":  "http://fasb.org/srt/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "srt_MinimumMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Minimum [Member]",
                            "terseLabel":  "Minimum"
                            }
                        }
                    },
                "localname":  "MinimumMember",
                "nsuri":  "http://fasb.org/srt/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "srt_NameOfMajorCustomerDomain":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Customer [Domain]",
                            "terseLabel":  "Customer [Domain]"
                            }
                        }
                    },
                "localname":  "NameOfMajorCustomerDomain",
                "nsuri":  "http://fasb.org/srt/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "srt_RangeAxis":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Range [Axis]",
                            "terseLabel":  "Range [Axis]"
                            }
                        }
                    },
                "localname":  "RangeAxis",
                "nsuri":  "http://fasb.org/srt/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "srt_RangeMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Range [Domain]",
                            "terseLabel":  "Range [Domain]"
                            }
                        }
                    },
                "localname":  "RangeMember",
                "nsuri":  "http://fasb.org/srt/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis":  {
                "auth_ref":  [
                    "r218"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Name of Property [Axis]",
                            "terseLabel":  "Name of Property [Axis]"
                            }
                        }
                    },
                "localname":  "RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis",
                "nsuri":  "http://fasb.org/srt/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Name of Property [Domain]",
                            "terseLabel":  "Name of Property [Domain]"
                            }
                        }
                    },
                "localname":  "RealEstateAndAccumulatedDepreciationNameOfPropertyDomain",
                "nsuri":  "http://fasb.org/srt/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_AccountsPayableCurrent":  {
                "auth_ref":  [
                    "r18"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_LiabilitiesCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.  Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
                            "label":  "Accounts Payable, Current",
                            "terseLabel":  "Accounts payable"
                            }
                        }
                    },
                "localname":  "AccountsPayableCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_AccountsPayableRelatedPartiesCurrent":  {
                "auth_ref":  [
                    "r18",
                    "r75",
                    "r181",
                    "r183",
                    "r184"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_LiabilitiesCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount for accounts payable to related parties.  Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
                            "label":  "Accounts Payable, Related Parties, Current",
                            "terseLabel":  "Accounts payable to affiliates"
                            }
                        }
                    },
                "localname":  "AccountsPayableRelatedPartiesCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_AccountsReceivableGrossCurrent":  {
                "auth_ref":  [
                    "r7",
                    "r208"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/AccountsReceivableDetails":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_AccountsReceivableNetCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amounts due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer) for goods or services (including trade receivables) that have been delivered or sold in the normal course of business.",
                            "label":  "Accounts Receivable, Gross, Current",
                            "terseLabel":  "Accounts receivable, trade"
                            }
                        }
                    },
                "localname":  "AccountsReceivableGrossCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/AccountsReceivableDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_AccountsReceivableNetAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Accounts Receivable, Net [Abstract]"
                            }
                        }
                    },
                "localname":  "AccountsReceivableNetAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_AccountsReceivableNetCurrent":  {
                "auth_ref":  [
                    "r7",
                    "r104"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/AccountsReceivableDetails":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        },
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_AssetsCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.",
                            "label":  "Accounts Receivable, Net, Current",
                            "terseLabel":  "Accounts receivable, net",
                            "totalLabel":  "Accounts receivable, net"
                            }
                        }
                    },
                "localname":  "AccountsReceivableNetCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/AccountsReceivableDetails",
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_AccruedLiabilitiesCurrent":  {
                "auth_ref":  [
                    "r19"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_LiabilitiesCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered.  Examples include taxes, interest, rent and utilities.  Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
                            "label":  "Accrued Liabilities, Current",
                            "terseLabel":  "Accrued liabilities"
                            }
                        }
                    },
                "localname":  "AccruedLiabilitiesCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax":  {
                "auth_ref":  [
                    "r33",
                    "r35",
                    "r36"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_StockholdersEquity",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end.  Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners.  Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.",
                            "label":  "Accumulated Other Comprehensive Income (Loss), Net of Tax",
                            "terseLabel":  "Accumulated other comprehensive loss"
                            }
                        }
                    },
                "localname":  "AccumulatedOtherComprehensiveIncomeLossNetOfTax",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_AccumulatedOtherComprehensiveIncomeMember":  {
                "auth_ref":  [
                    "r32",
                    "r36",
                    "r39",
                    "r151"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Accumulated increase (decrease) in equity from transactions and other events and circumstances from non-owner sources, attributable to the parent.  Excludes net income (loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners.",
                            "label":  "AOCI Attributable to Parent [Member]",
                            "terseLabel":  "AOCI Attributable to Parent"
                            }
                        }
                    },
                "localname":  "AccumulatedOtherComprehensiveIncomeMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_AdditionalPaidInCapital":  {
                "auth_ref":  [
                    "r8"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_StockholdersEquity",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders.  Includes adjustments to additional paid in capital.  Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees.  Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock.  For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock.  For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.",
                            "label":  "Additional Paid in Capital",
                            "terseLabel":  "Additional paid-in capital"
                            }
                        }
                    },
                "localname":  "AdditionalPaidInCapital",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_AdditionalPaidInCapitalMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders.",
                            "label":  "Additional Paid-in Capital [Member]",
                            "terseLabel":  "Additional Paid-in Capital"
                            }
                        }
                    },
                "localname":  "AdditionalPaidInCapitalMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]",
                            "terseLabel":  "Adjustments to reconcile net income to net cash provided by operating activities:"
                            }
                        }
                    },
                "localname":  "AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent":  {
                "auth_ref":  [
                    "r27",
                    "r92"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/AccountsReceivableDetails":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_AccountsReceivableNetCurrent",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.",
                            "label":  "Allowance for Doubtful Accounts Receivable, Current",
                            "negatedTerseLabel":  "Less allowance for doubtful accounts"
                            }
                        }
                    },
                "localname":  "AllowanceForDoubtfulAccountsReceivableCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/AccountsReceivableDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_Assets":  {
                "auth_ref":  [
                    "r87",
                    "r202",
                    "r209"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Sum of the carrying amounts as of the balance sheet date of all assets that are recognized.  Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
                            "label":  "Assets",
                            "totalLabel":  "TOTAL ASSETS"
                            }
                        }
                    },
                "localname":  "Assets",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_AssetsAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Assets [Abstract]",
                            "terseLabel":  "ASSETS"
                            }
                        }
                    },
                "localname":  "AssetsAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_AssetsCurrent":  {
                "auth_ref":  [
                    "r2",
                    "r3",
                    "r30"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_Assets",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer).  Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
                            "label":  "Assets, Current",
                            "totalLabel":  "Total current assets"
                            }
                        }
                    },
                "localname":  "AssetsCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_AssetsCurrentAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Assets, Current [Abstract]",
                            "terseLabel":  "Current assets:"
                            }
                        }
                    },
                "localname":  "AssetsCurrentAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_Assets",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Sum of the carrying amounts as of the balance sheet date of all assets, excluding property, plant, and equipment and other property and investments, that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer.  Alternate captions include Total Deferred Charges and Other Assets.",
                            "label":  "Assets, Noncurrent, Other than Noncurrent Investments and Property, Plant and Equipment",
                            "totalLabel":  "Total other assets, non-current"
                            }
                        }
                    },
                "localname":  "AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_CapitalExpendituresIncurredButNotYetPaid":  {
                "auth_ref":  [
                    "r65",
                    "r66",
                    "r67"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Future cash outflow to pay for purchases of fixed assets that have occurred.",
                            "label":  "Capital Expenditures Incurred but Not yet Paid",
                            "terseLabel":  "Property, plant and equipment acquired with accrued liabilities"
                            }
                        }
                    },
                "localname":  "CapitalExpendituresIncurredButNotYetPaid",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_CarryingReportedAmountFairValueDisclosureMember":  {
                "auth_ref":  [
                    "r161",
                    "r162"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Measured as reported on the statement of financial position (balance sheet).",
                            "label":  "Reported Value Measurement [Member]",
                            "terseLabel":  "Carrying Amount"
                            }
                        }
                    },
                "localname":  "CarryingReportedAmountFairValueDisclosureMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_CashAndCashEquivalentsAtCarryingValue":  {
                "auth_ref":  [
                    "r0",
                    "r14",
                    "r63"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_AssetsCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of currency on hand as well as demand deposits with banks or financial institutions.  Includes other kinds of accounts that have the general characteristics of demand deposits.  Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.  Excludes cash and cash equivalents within disposal group and discontinued operation.",
                            "label":  "Cash and Cash Equivalents, at Carrying Value",
                            "periodEndLabel":  "Cash, end of period",
                            "periodStartLabel":  "Cash, beginning of period",
                            "terseLabel":  "Cash"
                            }
                        }
                    },
                "localname":  "CashAndCashEquivalentsAtCarryingValue",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect":  {
                "auth_ref":  [
                    "r56",
                    "r163"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of increase (decrease) in cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; excluding effect from exchange rate change.  Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.  Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.",
                            "label":  "Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect",
                            "totalLabel":  "Net change in cash"
                            }
                        }
                    },
                "localname":  "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_CashFlowSupplementalDisclosuresTextBlock":  {
                "auth_ref":  [
                    "r68"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure for supplemental cash flow activities, including cash, noncash, and part noncash transactions, for the period.  Noncash is defined as information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. \"Part noncash\" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.",
                            "label":  "Cash Flow, Supplemental Disclosures [Text Block]",
                            "terseLabel":  "Supplemental Disclosure of Cash Flow Information"
                            }
                        }
                    },
                "localname":  "CashFlowSupplementalDisclosuresTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformation"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_CommitmentsAndContingencies":  {
                "auth_ref":  [
                    "r23",
                    "r96",
                    "r206",
                    "r214"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_LiabilitiesAndStockholdersEquity",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Represents the caption on the face of the balance sheet to indicate that the entity has entered into (1) purchase or supply arrangements that will require expending a portion of its resources to meet the terms thereof, and (2) is exposed to potential losses or, less frequently, gains, arising from (a) possible claims against a company's resources due to future performance under contract terms, and (b) possible losses or likely gains from uncertainties that will ultimately be resolved when one or more future events that are deemed likely to occur do occur or fail to occur.",
                            "label":  "Commitments and Contingencies",
                            "terseLabel":  "Commitments and contingencies (Notes 5, 6 and 9)"
                            }
                        }
                    },
                "localname":  "CommitmentsAndContingencies",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_CommitmentsAndContingenciesDisclosureAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Commitments and Contingencies Disclosure [Abstract]"
                            }
                        }
                    },
                "localname":  "CommitmentsAndContingenciesDisclosureAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_CommitmentsAndContingenciesDisclosureTextBlock":  {
                "auth_ref":  [
                    "r95",
                    "r97"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure for commitments and contingencies.",
                            "label":  "Commitments and Contingencies Disclosure [Text Block]",
                            "terseLabel":  "Commitments and Contingencies"
                            }
                        }
                    },
                "localname":  "CommitmentsAndContingenciesDisclosureTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CommitmentAndContingencies"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_CommonStockMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Stock that is subordinate to all other stock of the issuer.",
                            "label":  "Common Stock [Member]",
                            "terseLabel":  "Common Stock"
                            }
                        }
                    },
                "localname":  "CommonStockMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_CommonStockParOrStatedValuePerShare":  {
                "auth_ref":  [
                    "r6"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Face amount or stated value per share of common stock.",
                            "label":  "Common Stock, Par or Stated Value Per Share",
                            "terseLabel":  "Common Stock, Par Value (usd per share)"
                            }
                        }
                    },
                "localname":  "CommonStockParOrStatedValuePerShare",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheetsParenthetical"
                    ],
                "xbrltype":  "perShareItemType"
                },
            "us-gaap_CommonStockSharesAuthorized":  {
                "auth_ref":  [
                    "r6"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The maximum number of common shares permitted to be issued by an entity's charter and bylaws.",
                            "label":  "Common Stock, Shares Authorized",
                            "terseLabel":  "Common Stock, Shares authorized"
                            }
                        }
                    },
                "localname":  "CommonStockSharesAuthorized",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheetsParenthetical"
                    ],
                "xbrltype":  "sharesItemType"
                },
            "us-gaap_CommonStockSharesIssued":  {
                "auth_ref":  [
                    "r6"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury).  These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized.  Shares issued include shares outstanding and shares held in the treasury.",
                            "label":  "Common Stock, Shares, Issued",
                            "periodEndLabel":  "Common Stock, Shares Issued - Ending Balance",
                            "periodStartLabel":  "Common Stock, Shares Issued - Beginning Balance",
                            "terseLabel":  "Common Stock, Shares Issued"
                            }
                        }
                    },
                "localname":  "CommonStockSharesIssued",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheetsParenthetical",
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "sharesItemType"
                },
            "us-gaap_CommonStockValue":  {
                "auth_ref":  [
                    "r6"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_StockholdersEquity",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer).  This item includes treasury stock repurchased by the entity.  Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.",
                            "label":  "Common Stock, Value, Issued",
                            "terseLabel":  "Common stock $1 par value; 50,000,000 shares authorized; 23,416,396 shares issued"
                            }
                        }
                    },
                "localname":  "CommonStockValue",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest":  {
                "auth_ref":  [
                    "r41",
                    "r42",
                    "r150",
                    "r153"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income.  Excludes changes in equity resulting from investments by owners and distributions to owners.",
                            "label":  "Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest",
                            "totalLabel":  "Comprehensive income"
                            }
                        }
                    },
                "localname":  "ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_CostsAndExpensesRelatedParty":  {
                "auth_ref":  [
                    "r47"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Costs of sales and operating expenses for the period incurred from transactions with related parties.",
                            "label":  "Costs and Expenses, Related Party",
                            "terseLabel":  "Fuel, purchased power, and operations & maintenance"
                            }
                        }
                    },
                "localname":  "CostsAndExpensesRelatedParty",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption":  {
                "auth_ref":  [
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.",
                            "label":  "Cumulative Effect of New Accounting Principle in Period of Adoption",
                            "terseLabel":  "Cumulative effect of ASC 842 implementation"
                            }
                        }
                    },
                "localname":  "CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DeferredFuelCostsMember":  {
                "auth_ref":  [
                    "r219"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Rate action of a regulator resulting in capitalization or accrual of fuel costs incurred.",
                            "label":  "Deferred Fuel Costs [Member]",
                            "terseLabel":  "Deferred energy and fuel cost adjustments"
                            }
                        }
                    },
                "localname":  "DeferredFuelCostsMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_DeferredIncomeTaxExpenseBenefit":  {
                "auth_ref":  [
                    "r61",
                    "r72",
                    "r144",
                    "r145"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.",
                            "label":  "Deferred Income Tax Expense (Benefit)",
                            "terseLabel":  "Deferred income tax"
                            }
                        }
                    },
                "localname":  "DeferredIncomeTaxExpenseBenefit",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DeferredTaxLiabilitiesNoncurrent":  {
                "auth_ref":  [
                    "r141",
                    "r142",
                    "r143"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences, with jurisdictional netting and classified as noncurrent.",
                            "label":  "Deferred Tax Liabilities, Net, Noncurrent",
                            "terseLabel":  "Deferred income tax liabilities, net"
                            }
                        }
                    },
                "localname":  "DeferredTaxLiabilitiesNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DefinedBenefitPensionPlansAndDefinedBenefitPostretirementPlansDisclosureAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Defined Benefit Plan [Abstract]"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPensionPlansAndDefinedBenefitPostretirementPlansDisclosureAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses":  {
                "auth_ref":  [
                    "r123",
                    "r135",
                    "r138"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.",
                            "label":  "Defined Benefit Plan, Amortization of Gain (Loss)",
                            "negatedTerseLabel":  "Net loss (gain)"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanAmortizationOfGainsLosses",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit":  {
                "auth_ref":  [
                    "r124",
                    "r136",
                    "r138"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails":  {
                        "order":  5.0,
                        "parentTag":  "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.",
                            "label":  "Defined Benefit Plan, Amortization of Prior Service Cost (Credit)",
                            "terseLabel":  "Prior service cost (benefit)"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanAmortizationOfPriorServiceCostCredit",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DefinedBenefitPlanContributionsByEmployer":  {
                "auth_ref":  [
                    "r114",
                    "r116",
                    "r117",
                    "r137",
                    "r138"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of contribution received by defined benefit plan from employer which increases plan assets.",
                            "label":  "Defined Benefit Plan, Plan Assets, Contributions by Employer",
                            "terseLabel":  "Contributions"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanContributionsByEmployer",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DefinedBenefitPlanDisclosureLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Line items represent financial concepts included in a table.  These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
                            "label":  "Defined Benefit Plan Disclosure [Line Items]",
                            "terseLabel":  "Defined Benefit Plan Disclosure [Line Items]"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanDisclosureLineItems",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear":  {
                "auth_ref":  [
                    "r118"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of contributions expected to be received by defined benefit plan from employer in next fiscal year following latest fiscal year.",
                            "label":  "Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year",
                            "terseLabel":  "Anticipated Contributions for"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear":  {
                "auth_ref":  [
                    "r137"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of contributions expected to be received by defined benefit plan from employer in fiscal year.  Excludes contributions paid by employer in current fiscal year.",
                            "label":  "Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year",
                            "terseLabel":  "Remaining Anticipated Contributions for"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets":  {
                "auth_ref":  [
                    "r122",
                    "r134",
                    "r138"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.",
                            "label":  "Defined Benefit Plan, Expected Return (Loss) on Plan Assets",
                            "negatedTerseLabel":  "Expected return on plan assets"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanExpectedReturnOnPlanAssets",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DefinedBenefitPlanInterestCost":  {
                "auth_ref":  [
                    "r113",
                    "r121",
                    "r133",
                    "r138"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cost recognized for passage of time related to defined benefit plan.",
                            "label":  "Defined Benefit Plan, Interest Cost",
                            "terseLabel":  "Interest cost"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanInterestCost",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost":  {
                "auth_ref":  [
                    "r119",
                    "r131",
                    "r138"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of net periodic benefit cost (credit) for defined benefit plan.",
                            "label":  "Defined Benefit Plan, Net Periodic Benefit Cost (Credit)",
                            "totalLabel":  "Net periodic benefit cost"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanNetPeriodicBenefitCost",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]",
                            "terseLabel":  "Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanNetPeriodicBenefitCostAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_DefinedBenefitPlanServiceCost":  {
                "auth_ref":  [
                    "r112",
                    "r120",
                    "r132",
                    "r138"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.",
                            "label":  "Defined Benefit Plan, Service Cost",
                            "terseLabel":  "Service cost"
                            }
                        }
                    },
                "localname":  "DefinedBenefitPlanServiceCost",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DepreciationDepletionAndAmortization":  {
                "auth_ref":  [
                    "r61",
                    "r85"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_OperatingExpenses",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.",
                            "label":  "Depreciation, Depletion and Amortization",
                            "terseLabel":  "Depreciation and amortization"
                            }
                        }
                    },
                "localname":  "DepreciationDepletionAndAmortization",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_DisaggregationOfRevenueLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Line items represent financial concepts included in a table.  These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
                            "label":  "Disaggregation of Revenue [Line Items]",
                            "terseLabel":  "Disaggregation of Revenue [Line Items]"
                            }
                        }
                    },
                "localname":  "DisaggregationOfRevenueLineItems",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_DisaggregationOfRevenueTable":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Disclosure of information about disaggregation of revenue into categories depicting how nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factor.",
                            "label":  "Disaggregation of Revenue [Table]",
                            "terseLabel":  "Disaggregation of Revenue [Table]"
                            }
                        }
                    },
                "localname":  "DisaggregationOfRevenueTable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_DisaggregationOfRevenueTableTextBlock":  {
                "auth_ref":  [
                    "r103"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of disaggregation of revenue into categories depicting how nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factor.",
                            "label":  "Disaggregation of Revenue [Table Text Block]",
                            "terseLabel":  "Disaggregation of Revenue"
                            }
                        }
                    },
                "localname":  "DisaggregationOfRevenueTableTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_DueFromAffiliateCurrent":  {
                "auth_ref":  [
                    "r25",
                    "r75",
                    "r180",
                    "r182",
                    "r184",
                    "r188"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_AssetsCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership, due within 1 year (or 1 business cycle).",
                            "label":  "Due from Affiliate, Current",
                            "terseLabel":  "Accounts receivable from affiliates"
                            }
                        }
                    },
                "localname":  "DueFromAffiliateCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_EnvironmentalRestorationCostsMember":  {
                "auth_ref":  [
                    "r223"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Rate action of a regulator resulting in capitalization or accrual of costs associated with site remediation or other environmental exit costs that may occur on the sale, disposal, abandonment or decommissioning of a property.",
                            "label":  "Environmental Restoration Costs [Member]",
                            "verboseLabel":  "Decommissioning costs"
                            }
                        }
                    },
                "localname":  "EnvironmentalRestorationCostsMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_EquityComponentDomain":  {
                "auth_ref":  [
                    "r99"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Components of equity are the parts of the total Equity balance including that which is allocated to common, preferred, treasury stock, retained earnings, etc.",
                            "label":  "Equity Component [Domain]",
                            "terseLabel":  "Equity Component [Domain]"
                            }
                        }
                    },
                "localname":  "EquityComponentDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_EstimateOfFairValueFairValueDisclosureMember":  {
                "auth_ref":  [
                    "r160"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Measured as an estimate of fair value.",
                            "label":  "Estimate of Fair Value Measurement [Member]",
                            "terseLabel":  "Fair Value"
                            }
                        }
                    },
                "localname":  "EstimateOfFairValueFairValueDisclosureMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Line items represent financial concepts included in a table.  These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
                            "label":  "Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]",
                            "terseLabel":  "Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]"
                            }
                        }
                    },
                "localname":  "FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_FairValueByBalanceSheetGroupingTable":  {
                "auth_ref":  [
                    "r156",
                    "r161",
                    "r162"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Disclosure of information about the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.",
                            "label":  "Fair Value, by Balance Sheet Grouping [Table]",
                            "terseLabel":  "Fair Value, by Balance Sheet Grouping [Table]"
                            }
                        }
                    },
                "localname":  "FairValueByBalanceSheetGroupingTable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_FairValueByBalanceSheetGroupingTextBlock":  {
                "auth_ref":  [
                    "r156",
                    "r161"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.",
                            "label":  "Fair Value, by Balance Sheet Grouping [Table Text Block]",
                            "terseLabel":  "Schedule of Fair Value of Financial Instruments"
                            }
                        }
                    },
                "localname":  "FairValueByBalanceSheetGroupingTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_FairValueByMeasurementBasisAxis":  {
                "auth_ref":  [
                    "r156",
                    "r157"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by measurement basis.",
                            "label":  "Measurement Basis [Axis]",
                            "terseLabel":  "Measurement Basis [Axis]"
                            }
                        }
                    },
                "localname":  "FairValueByMeasurementBasisAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_FairValueDisclosureItemAmountsDomain":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Measurement basis, for example, but not limited to, reported value, fair value, portion at fair value, portion at other than fair value.",
                            "label":  "Fair Value Measurement [Domain]",
                            "terseLabel":  "Portion At Fair Value Disclosure [Domain]"
                            }
                        }
                    },
                "localname":  "FairValueDisclosureItemAmountsDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_FairValueDisclosuresAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Fair Value Disclosures [Abstract]"
                            }
                        }
                    },
                "localname":  "FairValueDisclosuresAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_FairValueDisclosuresTextBlock":  {
                "auth_ref":  [
                    "r158"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities.  Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.",
                            "label":  "Fair Value Disclosures [Text Block]",
                            "terseLabel":  "Fair Value of Financial Instruments"
                            }
                        }
                    },
                "localname":  "FairValueDisclosuresTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstruments"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments":  {
                "auth_ref":  [
                    "r74"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.",
                            "label":  "Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest",
                            "totalLabel":  "Income before income taxes"
                            }
                        }
                    },
                "localname":  "IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_IncomeStatementAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Income Statement [Abstract]"
                            }
                        }
                    },
                "localname":  "IncomeStatementAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_IncomeTaxExpenseBenefit":  {
                "auth_ref":  [
                    "r72",
                    "r86",
                    "r146"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.",
                            "label":  "Income Tax Expense (Benefit)",
                            "negatedTerseLabel":  "Income tax expense"
                            }
                        }
                    },
                "localname":  "IncomeTaxExpenseBenefit",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets":  {
                "auth_ref":  [
                    "r60"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  6.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of increase (decrease) in receivables, and operating assets classified as other.",
                            "label":  "Increase (Decrease) in Accounts Receivable and Other Operating Assets",
                            "negatedTerseLabel":  "Accounts receivable and other current assets"
                            }
                        }
                    },
                "localname":  "IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_IncreaseDecreaseInNotesPayableRelatedPartiesCurrent":  {
                "auth_ref":  [
                    "r60"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInFinancingActivities",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The increase (decrease) during the reporting period in the current portion (due within one year or one business cycle, whichever is longer) of the amount owed by the reporting entity in the form of loans and obligations (generally evidenced by promissory notes) made by the following types of related parties: a parent company and its subsidiaries; subsidiaries of a common parent; an entity and trust for the benefit of employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; an entity and its principal owners, management, or member of their immediate families; affiliates; or other parties with the ability to exert significant influence.",
                            "label":  "Increase (Decrease) in Notes Payable, Related Parties, Current",
                            "terseLabel":  "Change in money pool notes payable, net"
                            }
                        }
                    },
                "localname":  "IncreaseDecreaseInNotesPayableRelatedPartiesCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_IncreaseDecreaseInOperatingCapitalAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Increase (Decrease) in Operating Capital [Abstract]",
                            "terseLabel":  "Change in operating assets and liabilities:"
                            }
                        }
                    },
                "localname":  "IncreaseDecreaseInOperatingCapitalAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_IncreaseDecreaseInOtherAccountsPayableAndAccruedLiabilities":  {
                "auth_ref":  [
                    "r60"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  7.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The increase (decrease) during the reporting period in other obligations or expenses incurred but not yet paid.",
                            "label":  "Increase (Decrease) in Other Accounts Payable and Accrued Liabilities",
                            "terseLabel":  "Accounts payable and other current liabilities"
                            }
                        }
                    },
                "localname":  "IncreaseDecreaseInOtherAccountsPayableAndAccruedLiabilities",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet":  {
                "auth_ref":  [
                    "r60"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  11.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of increase (decrease) in operating assets after deduction of operating liabilities classified as other.",
                            "label":  "Increase (Decrease) in Other Operating Assets and Liabilities, Net",
                            "negatedTerseLabel":  "Other operating activities, net"
                            }
                        }
                    },
                "localname":  "IncreaseDecreaseInOtherOperatingCapitalNet",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_IncreaseDecreaseInOtherRegulatoryAssets":  {
                "auth_ref":  [
                    "r60"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  8.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The increase (decrease) during the reporting period in the value of other assets that are created when regulatory agencies permits public utilities to defer costs to the balance sheet.",
                            "label":  "Increase (Decrease) in Other Regulatory Assets",
                            "negatedTerseLabel":  "Regulatory assets - current"
                            }
                        }
                    },
                "localname":  "IncreaseDecreaseInOtherRegulatoryAssets",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_IncreaseDecreaseInRegulatoryLiabilities":  {
                "auth_ref":  [
                    "r60"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  9.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The increase (decrease) during the reporting period in regulated liabilities.  Regulated liabilities are created when regulatory agency permits an entity to defer revenues to the balance sheet.",
                            "label":  "Increase (Decrease) in Regulatory Liabilities",
                            "terseLabel":  "Regulatory liabilities - current"
                            }
                        }
                    },
                "localname":  "IncreaseDecreaseInRegulatoryLiabilities",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_IncreaseDecreaseInStockholdersEquityRollForward":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
                            "label":  "Increase (Decrease) in Stockholders' Equity [Roll Forward]",
                            "terseLabel":  "Increase (Decrease) in Stockholders' Equity [Roll Forward]"
                            }
                        }
                    },
                "localname":  "IncreaseDecreaseInStockholdersEquityRollForward",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_InterestCostsIncurred":  {
                "auth_ref":  [
                    "r164"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_NonoperatingIncomeExpense",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Total interest costs incurred during the period and either capitalized or charged against earnings.",
                            "label":  "Interest Costs Incurred",
                            "negatedTerseLabel":  "Interest expense incurred (including amortization of debt issuance costs, premiums, and discounts)"
                            }
                        }
                    },
                "localname":  "InterestCostsIncurred",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_InterestIncomeExpenseNet":  {
                "auth_ref":  [
                    "r207"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The net amount of operating interest income (expense).",
                            "label":  "Interest Income (Expense), Net",
                            "terseLabel":  "Net interest income (expense)"
                            }
                        }
                    },
                "localname":  "InterestIncomeExpenseNet",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_InterestPaidNet":  {
                "auth_ref":  [
                    "r55",
                    "r57",
                    "r64"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cash paid for interest, excluding capitalized interest, classified as operating activity.  Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.",
                            "label":  "Interest Paid, Excluding Capitalized Interest, Operating Activities",
                            "negatedTerseLabel":  "Interest (net of amounts capitalized)"
                            }
                        }
                    },
                "localname":  "InterestPaidNet",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_InventoryNet":  {
                "auth_ref":  [
                    "r1",
                    "r28",
                    "r94"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_AssetsCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.",
                            "label":  "Inventory, Net",
                            "terseLabel":  "Materials, supplies and fuel"
                            }
                        }
                    },
                "localname":  "InventoryNet",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_InvestmentIncomeInterest":  {
                "auth_ref":  [
                    "r48",
                    "r84"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_NonoperatingIncomeExpense",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.",
                            "label":  "Investment Income, Interest",
                            "terseLabel":  "Interest income"
                            }
                        }
                    },
                "localname":  "InvestmentIncomeInterest",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LeaseAgreementsMember":  {
                "auth_ref":  [
                    "r147"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Contractual agreement that stipulates the lessee pay the lessor for use of an asset.",
                            "label":  "Lease Agreements [Member]",
                            "terseLabel":  "Rent from electric properties"
                            }
                        }
                    },
                "localname":  "LeaseAgreementsMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_LeaseCost":  {
                "auth_ref":  [
                    "r176",
                    "r178"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lease cost recognized by lessee for lease contract.",
                            "label":  "Lease, Cost",
                            "terseLabel":  "Total lease cost"
                            }
                        }
                    },
                "localname":  "LeaseCost",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesLeaseCostsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LeaseCostTableTextBlock":  {
                "auth_ref":  [
                    "r176"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of lessee's lease cost.  Includes, but is not limited to, interest expense for finance lease, amortization of right-of-use asset for finance lease, operating lease cost, short-term lease cost, variable lease cost and sublease income.",
                            "label":  "Lease, Cost [Table Text Block]",
                            "terseLabel":  "Lease, Cost"
                            }
                        }
                    },
                "localname":  "LeaseCostTableTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_LeasesAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Leases [Abstract]"
                            }
                        }
                    },
                "localname":  "LeasesAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_LesseeLeaseDescriptionLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Line items represent financial concepts included in a table.  These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
                            "label":  "Lessee, Lease, Description [Line Items]",
                            "terseLabel":  "Lessee, Lease, Description [Line Items]"
                            }
                        }
                    },
                "localname":  "LesseeLeaseDescriptionLineItems",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_LesseeLeaseDescriptionTable":  {
                "auth_ref":  [
                    "r169"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Disclosure of information about lessee's leases.",
                            "label":  "Lessee, Lease, Description [Table]",
                            "terseLabel":  "Lessee, Lease, Description [Table]"
                            }
                        }
                    },
                "localname":  "LesseeLeaseDescriptionTable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock":  {
                "auth_ref":  [
                    "r177"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of undiscounted cash flows of lessee's operating lease liability.  Includes, but is not limited to, reconciliation of undiscounted cash flows to operating lease liability recognized in statement of financial position.",
                            "label":  "Lessee, Operating Lease, Liability, Maturity [Table Text Block]",
                            "terseLabel":  "Lessee, Operating Lease, Liability, Maturity"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue":  {
                "auth_ref":  [
                    "r177"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        },
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetailsCalc2":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lessee's undiscounted obligation for lease payments for operating lease.",
                            "label":  "Lessee, Operating Lease, Liability, Payments, Due",
                            "totalLabel":  "Total lease payments"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseLiabilityPaymentsDue",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive":  {
                "auth_ref":  [
                    "r177"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails":  {
                        "order":  6.0,
                        "parentTag":  "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lessee's undiscounted obligation for lease payments for operating lease, due after fifth fiscal year following latest fiscal year.",
                            "label":  "Lessee, Operating Lease, Liability, Payments, Due after Year Five",
                            "terseLabel":  "Thereafter"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive":  {
                "auth_ref":  [
                    "r177"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails":  {
                        "order":  5.0,
                        "parentTag":  "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fifth fiscal year following latest fiscal year.",
                            "label":  "Lessee, Operating Lease, Liability, Payments, Due Year Five",
                            "terseLabel":  "2023"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseLiabilityPaymentsDueYearFive",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour":  {
                "auth_ref":  [
                    "r177"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fourth fiscal year following latest fiscal year.",
                            "label":  "Lessee, Operating Lease, Liability, Payments, Due Year Four",
                            "terseLabel":  "2022"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseLiabilityPaymentsDueYearFour",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree":  {
                "auth_ref":  [
                    "r177"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lessee's undiscounted obligation for lease payments for operating lease, due in third fiscal year following latest fiscal year.",
                            "label":  "Lessee, Operating Lease, Liability, Payments, Due Year Three",
                            "terseLabel":  "2021"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseLiabilityPaymentsDueYearThree",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo":  {
                "auth_ref":  [
                    "r177"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lessee's undiscounted obligation for lease payments for operating lease, due in second fiscal year following latest fiscal year.",
                            "label":  "Lessee, Operating Lease, Liability, Payments, Due Year Two",
                            "terseLabel":  "2020"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseLiabilityPaymentsDueYearTwo",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear":  {
                "auth_ref":  [
                    "r177"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lessee's undiscounted obligation for lease payments for operating lease having an initial or remaining lease term in excess of one year due in remainder of fiscal year following latest fiscal year.",
                            "label":  "Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year",
                            "terseLabel":  "2019"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount":  {
                "auth_ref":  [
                    "r177"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetailsCalc2":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.",
                            "label":  "Lessee, Operating Lease, Liability, Undiscounted Excess Amount",
                            "terseLabel":  "Less imputed interest"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseLiabilityUndiscountedExcessAmount",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LesseeOperatingLeaseTermOfContract":  {
                "auth_ref":  [
                    "r168"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
                            "label":  "Lessee, Operating Lease, Term of Contract",
                            "terseLabel":  "Lessee, Operating Lease, Term of Contract"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeaseTermOfContract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesDetails"
                    ],
                "xbrltype":  "durationItemType"
                },
            "us-gaap_LesseeOperatingLeasesTextBlock":  {
                "auth_ref":  [
                    "r179"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure for operating leases of lessee.  Includes, but is not limited to, description of operating lease and maturity analysis of operating lease liability.",
                            "label":  "Lessee, Operating Leases [Text Block]",
                            "terseLabel":  "Leases"
                            }
                        }
                    },
                "localname":  "LesseeOperatingLeasesTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/Leases"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_LiabilitiesAndStockholdersEquity":  {
                "auth_ref":  [
                    "r12",
                    "r204",
                    "r212"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any.",
                            "label":  "Liabilities and Equity",
                            "totalLabel":  "TOTAL LIABILITIES AND STOCKHOLDER\u2019S EQUITY"
                            }
                        }
                    },
                "localname":  "LiabilitiesAndStockholdersEquity",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LiabilitiesAndStockholdersEquityAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Liabilities and Equity [Abstract]",
                            "terseLabel":  "LIABILITIES AND STOCKHOLDER\u2019S EQUITY"
                            }
                        }
                    },
                "localname":  "LiabilitiesAndStockholdersEquityAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_LiabilitiesCurrent":  {
                "auth_ref":  [
                    "r20"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_LiabilitiesAndStockholdersEquity",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer.",
                            "label":  "Liabilities, Current",
                            "totalLabel":  "Total current liabilities"
                            }
                        }
                    },
                "localname":  "LiabilitiesCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LiabilitiesCurrentAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Liabilities, Current [Abstract]",
                            "terseLabel":  "Current liabilities:"
                            }
                        }
                    },
                "localname":  "LiabilitiesCurrentAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_LiabilitiesNoncurrentAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Liabilities, Noncurrent [Abstract]",
                            "terseLabel":  "Deferred credits and other liabilities:"
                            }
                        }
                    },
                "localname":  "LiabilitiesNoncurrentAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_LiabilitiesAndStockholdersEquity",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Aggregated carrying amounts of obligations as of the balance sheet date, excluding long-term debt, incurred as part of the normal operations that are expected to be paid after one year or beyond the normal operating cycle, if longer.  Alternate captions include Total Deferred Credits and Other Liabilities.",
                            "label":  "Liabilities, Other than Long-term Debt, Noncurrent",
                            "totalLabel":  "Total deferred credits and other liabilities"
                            }
                        }
                    },
                "localname":  "LiabilitiesOtherThanLongtermDebtNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.",
                            "label":  "Line of Credit Facility, Unused Capacity, Commitment Fee Percentage",
                            "terseLabel":  "Commitment fee percentage"
                            }
                        }
                    },
                "localname":  "LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "percentItemType"
                },
            "us-gaap_LoansNotesTradeAndOtherReceivablesDisclosureTextBlock":  {
                "auth_ref":  [
                    "r7",
                    "r13",
                    "r90",
                    "r91",
                    "r92",
                    "r205",
                    "r213",
                    "r216"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure for claims held for amounts due a entity, excluding financing receivables.  Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables.  Includes disclosure for allowance for credit losses.",
                            "label":  "Loans, Notes, Trade and Other Receivables Disclosure [Text Block]",
                            "terseLabel":  "Accounts Receivable"
                            }
                        }
                    },
                "localname":  "LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/AccountsReceivable"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_LongTermDebt":  {
                "auth_ref":  [
                    "r4",
                    "r98",
                    "r203",
                    "r210"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt.  Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper.  Excludes capital lease obligations.",
                            "label":  "Long-term Debt",
                            "terseLabel":  "Long-term debt, including current maturities, carrying amount"
                            }
                        }
                    },
                "localname":  "LongTermDebt",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LongTermDebtFairValue":  {
                "auth_ref":  [
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure.  Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.  The element may be used in both the balance sheet and disclosure in the same submission.",
                            "label":  "Long-term Debt, Fair Value",
                            "terseLabel":  "Long-term debt, including current maturities, fair value"
                            }
                        }
                    },
                "localname":  "LongTermDebtFairValue",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LongTermDebtNoncurrent":  {
                "auth_ref":  [
                    "r21"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_LiabilitiesAndStockholdersEquity",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer.  Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper.  Excludes capital lease obligations.",
                            "label":  "Long-term Debt, Excluding Current Maturities",
                            "terseLabel":  "Long-term debt"
                            }
                        }
                    },
                "localname":  "LongTermDebtNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LongTermInvestments":  {
                "auth_ref":  [
                    "r15"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_Assets",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).",
                            "label":  "Long-term Investments",
                            "terseLabel":  "Investments"
                            }
                        }
                    },
                "localname":  "LongTermInvestments",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_LossOnReacquiredDebtMember":  {
                "auth_ref":  [
                    "r219",
                    "r224"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Rate action of a regulator resulting in capitalization or accrual of loss incurred on reacquisition or refinancing of debt.",
                            "label":  "Loss on Reacquired Debt [Member]",
                            "terseLabel":  "Loss on reacquired debt"
                            }
                        }
                    },
                "localname":  "LossOnReacquiredDebtMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_NetCashProvidedByUsedInContinuingOperationsAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Net Cash Provided by (Used in) Continuing Operations [Abstract]",
                            "terseLabel":  "Net Cash Provided by (Used in) Continuing Operations [Abstract]"
                            }
                        }
                    },
                "localname":  "NetCashProvidedByUsedInContinuingOperationsAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_NetCashProvidedByUsedInFinancingActivities":  {
                "auth_ref":  [
                    "r56"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cash inflow (outflow) from financing activities, including discontinued operations.  Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.",
                            "label":  "Net Cash Provided by (Used in) Financing Activities",
                            "totalLabel":  "Net cash provided by (used in) financing activities"
                            }
                        }
                    },
                "localname":  "NetCashProvidedByUsedInFinancingActivities",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Net Cash Provided by (Used in) Financing Activities [Abstract]",
                            "terseLabel":  "Financing activities:"
                            }
                        }
                    },
                "localname":  "NetCashProvidedByUsedInFinancingActivitiesAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_NetCashProvidedByUsedInInvestingActivities":  {
                "auth_ref":  [
                    "r56"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cash inflow (outflow) from investing activities, including discontinued operations.  Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.",
                            "label":  "Net Cash Provided by (Used in) Investing Activities",
                            "totalLabel":  "Net cash provided by (used in) investing activities"
                            }
                        }
                    },
                "localname":  "NetCashProvidedByUsedInInvestingActivities",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Net Cash Provided by (Used in) Investing Activities [Abstract]",
                            "terseLabel":  "Investing activities:"
                            }
                        }
                    },
                "localname":  "NetCashProvidedByUsedInInvestingActivitiesAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_NetCashProvidedByUsedInOperatingActivities":  {
                "auth_ref":  [
                    "r56",
                    "r59",
                    "r62"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect",
                        "weight":  1.0
                        }
                    },
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cash inflow (outflow) from operating activities, including discontinued operations.  Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.",
                            "label":  "Net Cash Provided by (Used in) Operating Activities",
                            "totalLabel":  "Net cash provided by (used in) operating activities"
                            }
                        }
                    },
                "localname":  "NetCashProvidedByUsedInOperatingActivities",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Net Cash Provided by (Used in) Operating Activities [Abstract]",
                            "terseLabel":  "Operating activities:"
                            }
                        }
                    },
                "localname":  "NetCashProvidedByUsedInOperatingActivitiesAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic":  {
                "auth_ref":  [
                    "r78",
                    "r80"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  1.0
                        },
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.",
                            "label":  "Net Income (Loss) Available to Common Stockholders, Basic",
                            "terseLabel":  "Net income",
                            "totalLabel":  "Net income"
                            }
                        }
                    },
                "localname":  "NetIncomeLossAvailableToCommonStockholdersBasic",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows",
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity",
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Disclosure of accounting policy pertaining to new accounting pronouncements that may impact the entity's financial reporting.  Includes, but is not limited to, quantification of the expected or actual impact.",
                            "label":  "New Accounting Pronouncements, Policy [Policy Text Block]",
                            "terseLabel":  "Recently Adopted Accounting Standards"
                            }
                        }
                    },
                "localname":  "NewAccountingPronouncementsPolicyPolicyTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/ManagementsStatementPolicies"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_NoncashInvestingAndFinancingItemsAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Noncash Investing and Financing Items [Abstract]",
                            "terseLabel":  "Noncash Investing and Financing Items [Abstract]"
                            }
                        }
                    },
                "localname":  "NoncashInvestingAndFinancingItemsAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_NonoperatingIncomeExpense":  {
                "auth_ref":  [
                    "r49"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).",
                            "label":  "Nonoperating Income (Expense)",
                            "totalLabel":  "Total other income (expense), net"
                            }
                        }
                    },
                "localname":  "NonoperatingIncomeExpense",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_NonoperatingIncomeExpenseAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Nonoperating Income (Expense) [Abstract]",
                            "terseLabel":  "Other income (expense):"
                            }
                        }
                    },
                "localname":  "NonoperatingIncomeExpenseAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_NotesPayableRelatedPartiesClassifiedCurrent":  {
                "auth_ref":  [
                    "r17",
                    "r75",
                    "r181"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  5.0,
                        "parentTag":  "us-gaap_LiabilitiesCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The amount for notes payable (written promise to pay), due to related parties.  Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
                            "label":  "Notes Payable, Related Parties, Current",
                            "terseLabel":  "Notes payable to Parent"
                            }
                        }
                    },
                "localname":  "NotesPayableRelatedPartiesClassifiedCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_NotesPayableRelatedPartiesCurrentAndNoncurrent":  {
                "auth_ref":  [
                    "r75",
                    "r180",
                    "r215"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_LiabilitiesCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The amount for notes payable (written promise to pay), due to related parties.",
                            "label":  "Notes Payable, Related Parties",
                            "terseLabel":  "Money pool notes payable"
                            }
                        }
                    },
                "localname":  "NotesPayableRelatedPartiesCurrentAndNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OperatingExpenses":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_OperatingIncomeLoss",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services.  Includes selling, general and administrative expense.",
                            "label":  "Operating Expenses",
                            "totalLabel":  "Total operating expenses"
                            }
                        }
                    },
                "localname":  "OperatingExpenses",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OperatingExpensesAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Operating Expenses [Abstract]",
                            "terseLabel":  "Operating expenses:"
                            }
                        }
                    },
                "localname":  "OperatingExpensesAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_OperatingIncomeLoss":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The net result for the period of deducting operating expenses from operating revenues.",
                            "label":  "Operating Income (Loss)",
                            "totalLabel":  "Operating income"
                            }
                        }
                    },
                "localname":  "OperatingIncomeLoss",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OperatingLeaseCost":  {
                "auth_ref":  [
                    "r170",
                    "r178"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term.  Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.",
                            "label":  "Operating Lease, Cost",
                            "terseLabel":  "Operating lease cost"
                            }
                        }
                    },
                "localname":  "OperatingLeaseCost",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesLeaseCostsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OperatingLeaseLiability":  {
                "auth_ref":  [
                    "r166"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetailsCalc2":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
                        "weight":  1.0
                        },
                    "http://www.blackhillscorp.com/role/LeasesSupplementalBalanceSheetInformationDetails":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Present value of lessee's discounted obligation for lease payments from operating lease.",
                            "label":  "Operating Lease, Liability",
                            "terseLabel":  "Operating Lease, Liability",
                            "totalLabel":  "Total lease liabilities",
                            "verboseLabel":  "Present value of lease liabilities"
                            }
                        }
                    },
                "localname":  "OperatingLeaseLiability",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesFutureMinimumPaymentsDetails",
                    "http://www.blackhillscorp.com/role/LeasesSupplementalBalanceSheetInformationDetails",
                    "http://www.blackhillscorp.com/role/ManagementStatementDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OperatingLeaseLiabilityCurrent":  {
                "auth_ref":  [
                    "r166"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesSupplementalBalanceSheetInformationDetails":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_OperatingLeaseLiability",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.",
                            "label":  "Operating Lease, Liability, Current",
                            "terseLabel":  "Operating lease liabilities, current"
                            }
                        }
                    },
                "localname":  "OperatingLeaseLiabilityCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesSupplementalBalanceSheetInformationDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OperatingLeaseLiabilityNoncurrent":  {
                "auth_ref":  [
                    "r166"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/LeasesSupplementalBalanceSheetInformationDetails":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_OperatingLeaseLiability",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.",
                            "label":  "Operating Lease, Liability, Noncurrent",
                            "terseLabel":  "Operating lease liabilities, noncurrent"
                            }
                        }
                    },
                "localname":  "OperatingLeaseLiabilityNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesSupplementalBalanceSheetInformationDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OperatingLeasePayments":  {
                "auth_ref":  [
                    "r167",
                    "r172"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.",
                            "label":  "Operating Lease, Payments",
                            "terseLabel":  "Operating cash flows from operating leases"
                            }
                        }
                    },
                "localname":  "OperatingLeasePayments",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesSupplementalCashFlowInformationDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OperatingLeaseRightOfUseAsset":  {
                "auth_ref":  [
                    "r165"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of lessee's right to use underlying asset under operating lease.",
                            "label":  "Operating Lease, Right-of-Use Asset",
                            "terseLabel":  "Operating lease assets"
                            }
                        }
                    },
                "localname":  "OperatingLeaseRightOfUseAsset",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesSupplementalBalanceSheetInformationDetails",
                    "http://www.blackhillscorp.com/role/ManagementStatementDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent":  {
                "auth_ref":  [
                    "r175",
                    "r178"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Weighted average discount rate for operating lease calculated at point in time.",
                            "label":  "Operating Lease, Weighted Average Discount Rate, Percent",
                            "terseLabel":  "Weighted average discount rate"
                            }
                        }
                    },
                "localname":  "OperatingLeaseWeightedAverageDiscountRatePercent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesWeightedAverageInformationDetails"
                    ],
                "xbrltype":  "percentItemType"
                },
            "us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1":  {
                "auth_ref":  [
                    "r174",
                    "r178"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
                            "label":  "Operating Lease, Weighted Average Remaining Lease Term",
                            "terseLabel":  "Weighted average remaining lease term (years)"
                            }
                        }
                    },
                "localname":  "OperatingLeaseWeightedAverageRemainingLeaseTerm1",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesWeightedAverageInformationDetails"
                    ],
                "xbrltype":  "durationItemType"
                },
            "us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Organization, Consolidation and Presentation of Financial Statements [Abstract]"
                            }
                        }
                    },
                "localname":  "OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock":  {
                "auth_ref":  [
                    "r77",
                    "r79",
                    "r81",
                    "r154"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure for the general note to the financial statements for the reporting entity which may include, descriptions of the basis of presentation, business description, significant accounting policies, consolidations, reclassifications, new pronouncements not yet adopted and changes in accounting principles.",
                            "label":  "Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]",
                            "terseLabel":  "Management's Statement"
                            }
                        }
                    },
                "localname":  "OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/ManagementsStatement"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_OtherAssetsCurrent":  {
                "auth_ref":  [
                    "r29"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  6.0,
                        "parentTag":  "us-gaap_AssetsCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of current assets classified as other.",
                            "label":  "Other Assets, Current",
                            "terseLabel":  "Other current assets"
                            }
                        }
                    },
                "localname":  "OtherAssetsCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherAssetsNoncurrent":  {
                "auth_ref":  [
                    "r16"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of noncurrent assets classified as other.",
                            "label":  "Other Assets, Noncurrent",
                            "terseLabel":  "Other assets, non-current"
                            }
                        }
                    },
                "localname":  "OtherAssetsNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherAssetsNoncurrentDisclosureAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Other Assets, Noncurrent Disclosure [Abstract]",
                            "terseLabel":  "Other assets:"
                            }
                        }
                    },
                "localname":  "OtherAssetsNoncurrentDisclosureAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_OtherComprehensiveIncomeLossNetOfTax":  {
                "auth_ref":  [
                    "r40",
                    "r42",
                    "r43",
                    "r99"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount after tax and reclassification adjustments of other comprehensive income (loss).",
                            "label":  "Other Comprehensive Income (Loss), Net of Tax",
                            "terseLabel":  "Other comprehensive income (loss), net of tax",
                            "totalLabel":  "Other comprehensive income (loss), net of tax"
                            }
                        }
                    },
                "localname":  "OtherComprehensiveIncomeLossNetOfTax",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity",
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Other Comprehensive Income (Loss), Net of Tax [Abstract]",
                            "terseLabel":  "Other comprehensive income (loss), net of tax:"
                            }
                        }
                    },
                "localname":  "OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax":  {
                "auth_ref":  [
                    "r31",
                    "r34",
                    "r150"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.",
                            "label":  "Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax",
                            "terseLabel":  "Reclassification adjustment of benefit and other postretirement plans included in net income, (tax) benefit"
                            }
                        }
                    },
                "localname":  "OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncomeParenthetical"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax":  {
                "auth_ref":  [
                    "r33",
                    "r37",
                    "r38",
                    "r155"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount after tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).",
                            "label":  "Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax",
                            "negatedTerseLabel":  "Reclassification of net realized (gains) losses on settled/amortized interest rate swaps (net of tax of $(3), $(6), $(10) and $(17), respectively)"
                            }
                        }
                    },
                "localname":  "OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax":  {
                "auth_ref":  [
                    "r34"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).",
                            "label":  "Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax",
                            "terseLabel":  "Reclassification adjustment of cash flow hedges settled, (tax) benefit"
                            }
                        }
                    },
                "localname":  "OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncomeParenthetical"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax":  {
                "auth_ref":  [
                    "r33",
                    "r37",
                    "r38",
                    "r125"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount, after tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.",
                            "label":  "Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax",
                            "negatedTerseLabel":  "Reclassification adjustment of benefit plan liability - net gain (loss) (net of tax of $(3), $(9), $(10) and $(27), respectively)"
                            }
                        }
                    },
                "localname":  "OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherLiabilitiesNoncurrent":  {
                "auth_ref":  [
                    "r22"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.",
                            "label":  "Other Liabilities, Noncurrent",
                            "terseLabel":  "Other deferred credits and other liabilities"
                            }
                        }
                    },
                "localname":  "OtherLiabilitiesNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherNoncashIncomeExpense":  {
                "auth_ref":  [
                    "r62"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  5.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of income (expense) included in net income that results in no cash inflow (outflow), classified as other.",
                            "label":  "Other Noncash Income (Expense)",
                            "negatedTerseLabel":  "Other adjustments, net"
                            }
                        }
                    },
                "localname":  "OtherNoncashIncomeExpense",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherNonoperatingIncomeExpense":  {
                "auth_ref":  [
                    "r50"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_NonoperatingIncomeExpense",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of income (expense) related to nonoperating activities, classified as other.",
                            "label":  "Other Nonoperating Income (Expense)",
                            "terseLabel":  "Other income (expense), net"
                            }
                        }
                    },
                "localname":  "OtherNonoperatingIncomeExpense",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember":  {
                "auth_ref":  [
                    "r109",
                    "r127",
                    "r128",
                    "r139"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Plan designed to provide other postretirement benefits.  Includes, but is not limited to, defined benefit and defined contribution plans.  Excludes pension benefits.",
                            "label":  "Other Postretirement Benefits Plan [Member]",
                            "terseLabel":  "Defined Benefit Postretirement Healthcare Plan"
                            }
                        }
                    },
                "localname":  "OtherPostretirementBenefitPlansDefinedBenefitMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_ParentMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Portion of equity, or net assets, in the consolidated entity attributable, directly or indirectly, to the parent.  Excludes noncontrolling interests.",
                            "label":  "Parent [Member]",
                            "terseLabel":  "Parent"
                            }
                        }
                    },
                "localname":  "ParentMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails",
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_PaymentsForProceedsFromOtherInvestingActivities":  {
                "auth_ref":  [
                    "r51",
                    "r53",
                    "r76"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInInvestingActivities",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cash (inflow) outflow from investing activities classified as other.",
                            "label":  "Payments for (Proceeds from) Other Investing Activities",
                            "negatedTerseLabel":  "Other investing activities"
                            }
                        }
                    },
                "localname":  "PaymentsForProceedsFromOtherInvestingActivities",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_PaymentsToAcquirePropertyPlantAndEquipment":  {
                "auth_ref":  [
                    "r52"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInInvestingActivities",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.",
                            "label":  "Payments to Acquire Property, Plant, and Equipment",
                            "negatedTerseLabel":  "Property, plant and equipment additions"
                            }
                        }
                    },
                "localname":  "PaymentsToAcquirePropertyPlantAndEquipment",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_PensionAndOtherPostretirementBenefitContributionsAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Payment for Pension and Other Postretirement Benefits [Abstract]",
                            "terseLabel":  "Payment for Pension and Other Postretirement Benefits [Abstract]"
                            }
                        }
                    },
                "localname":  "PensionAndOtherPostretirementBenefitContributionsAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_PensionAndOtherPostretirementBenefitExpense":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cost (reversal of cost) for pension and other postretirement benefits.",
                            "label":  "Pension and Other Postretirement Benefits Cost (Reversal of Cost)",
                            "terseLabel":  "Employee benefits"
                            }
                        }
                    },
                "localname":  "PensionAndOtherPostretirementBenefitExpense",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock":  {
                "auth_ref":  [
                    "r140"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure for pension and other postretirement benefits.",
                            "label":  "Pension and Other Postretirement Benefits Disclosure [Text Block]",
                            "terseLabel":  "Employee Benefit Plans"
                            }
                        }
                    },
                "localname":  "PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlans"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent":  {
                "auth_ref":  [
                    "r5",
                    "r110",
                    "r111",
                    "r115"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent.",
                            "label":  "Liability, Defined Benefit Plan, Noncurrent",
                            "terseLabel":  "Benefit plan liabilities"
                            }
                        }
                    },
                "localname":  "PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_PensionAndOtherPostretirementPlansCostsMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Rate action of a regulator resulting in capitalization or accrual of pension and other postretirement costs.",
                            "label":  "Pension and Other Postretirement Plans Costs [Member]",
                            "terseLabel":  "Employee benefit plan costs and related deferred taxes"
                            }
                        }
                    },
                "localname":  "PensionAndOtherPostretirementPlansCostsMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails",
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_PensionContributions":  {
                "auth_ref":  [
                    "r58"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  10.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cash outflow for pension benefit.  Includes, but is not limited to, employer contribution to fund plan asset and payment to retiree.  Excludes other postretirement benefit.",
                            "label":  "Payment for Pension Benefits",
                            "negatedTerseLabel":  "Payment for Pension Benefits"
                            }
                        }
                    },
                "localname":  "PensionContributions",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_PensionPlansDefinedBenefitMember":  {
                "auth_ref":  [
                    "r108",
                    "r127",
                    "r128",
                    "r139"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Plan designed to provide participant with pension benefits.  Includes, but is not limited to, defined benefit and defined contribution plans.  Excludes other postretirement benefits.",
                            "label":  "Pension Plan [Member]",
                            "terseLabel":  "Defined Benefit Pension Plan"
                            }
                        }
                    },
                "localname":  "PensionPlansDefinedBenefitMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_PortionAtFairValueFairValueDisclosureMember":  {
                "auth_ref":  [
                    "r159"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Measured at fair value for financial reporting purposes.",
                            "label":  "Portion at Fair Value Measurement [Member]",
                            "terseLabel":  "Portion at Fair Value Measurement"
                            }
                        }
                    },
                "localname":  "PortionAtFairValueFairValueDisclosureMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/FairValueOfFinancialInstrumentsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_ProceedsFromNotesPayable":  {
                "auth_ref":  [
                    "r54"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInFinancingActivities",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The cash inflow from a borrowing supported by a written promise to pay an obligation.",
                            "label":  "Proceeds from Notes Payable",
                            "terseLabel":  "Notes payable to Parent"
                            }
                        }
                    },
                "localname":  "ProceedsFromNotesPayable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_ProceedsFromSaleOfOtherAssetsInvestingActivities":  {
                "auth_ref":  [
                    "r51"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInInvestingActivities",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of cash inflow from the sale of other assets recognized in investing activities.",
                            "label":  "Proceeds from Sale of Other Assets, Investing Activities",
                            "terseLabel":  "Proceeds from sale of assets"
                            }
                        }
                    },
                "localname":  "ProceedsFromSaleOfOtherAssetsInvestingActivities",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_PublicUtilitiesGeneralDisclosuresLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Line items represent financial concepts included in a table.  These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
                            "label":  "Public Utilities, General Disclosures [Line Items]",
                            "terseLabel":  "Public Utilities, General Disclosures [Line Items]"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesGeneralDisclosuresLineItems",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_PublicUtilitiesGeneralDisclosuresTable":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Disclosure of information about regulation for public utility entities, including, but not limited to, rate requests, decommissioning costs and the amount of allowance for earnings on equity capitalized for rate making purposes.",
                            "label":  "Public Utilities General Disclosures [Table]",
                            "terseLabel":  "Public Utilities General Disclosures [Table]"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesGeneralDisclosuresTable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet",
                        "weight":  -1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Period end book value of accumulated depreciation on property, plant and equipment (PPE) that is owned by the regulated operations of the public utility.",
                            "label":  "Public Utilities, Property, Plant and Equipment, Accumulated Depreciation",
                            "negatedTerseLabel":  "Less: accumulated depreciation and amortization"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_Assets",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Period end amount of total net PPE.",
                            "label":  "Public Utilities, Property, Plant and Equipment, Net",
                            "totalLabel":  "Total property, plant and equipment, net"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesPropertyPlantAndEquipmentNet",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Period end amount of total gross PPE.",
                            "label":  "Public Utilities, Property, Plant and Equipment, Plant in Service",
                            "terseLabel":  "Property, plant and equipment"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesPropertyPlantAndEquipmentPlantInService",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_PublicUtilitiesRegulatoryProceedingAxis":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by name of regulatory proceeding.",
                            "label":  "Public Utilities, Regulatory Proceeding [Axis]",
                            "terseLabel":  "Public Utilities, Regulatory Proceeding [Axis]"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesRegulatoryProceedingAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_PublicUtilitiesRegulatoryProceedingDomain":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Proceeding with public utility's regulatory body.",
                            "label":  "Public Utilities, Regulatory Proceeding [Domain]",
                            "terseLabel":  "Public Utilities, Regulatory Proceeding [Domain]"
                            }
                        }
                    },
                "localname":  "PublicUtilitiesRegulatoryProceedingDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_RegulatedOperatingRevenueOther":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/RevenueDetails":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_Revenues",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The amount of regulated other operating revenues recognized during the period.",
                            "label":  "Regulated Operating Revenue, Other",
                            "terseLabel":  "Other revenues"
                            }
                        }
                    },
                "localname":  "RegulatedOperatingRevenueOther",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RegulatedOperationsAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Regulated Operations [Abstract]"
                            }
                        }
                    },
                "localname":  "RegulatedOperationsAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RegulatoryAgencyAxis":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by name of regulatory agency.",
                            "label":  "Regulatory Agency [Axis]",
                            "terseLabel":  "Regulatory Agency [Axis]"
                            }
                        }
                    },
                "localname":  "RegulatoryAgencyAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RegulatoryAgencyDomain":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Organization that establishes and ensures compliance with rules or regulations.",
                            "label":  "Regulatory Agency [Domain]",
                            "terseLabel":  "Regulatory Agency [Domain]"
                            }
                        }
                    },
                "localname":  "RegulatoryAgencyDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_RegulatoryAssetAxis":  {
                "auth_ref":  [
                    "r220",
                    "r221",
                    "r226"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by type of regulatory asset.",
                            "label":  "Regulatory Asset [Axis]",
                            "terseLabel":  "Regulatory Asset [Axis]"
                            }
                        }
                    },
                "localname":  "RegulatoryAssetAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RegulatoryAssetDomain":  {
                "auth_ref":  [
                    "r220"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Rate action of a regulator resulting in capitalization of costs incurred.",
                            "label":  "Regulatory Asset [Domain]",
                            "terseLabel":  "Regulatory Asset [Domain]"
                            }
                        }
                    },
                "localname":  "RegulatoryAssetDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_RegulatoryAssetLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Line items represent financial concepts included in a table.  These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
                            "label":  "Regulatory Assets [Line Items]",
                            "terseLabel":  "Regulatory Assets [Line Items]"
                            }
                        }
                    },
                "localname":  "RegulatoryAssetLineItems",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RegulatoryAssets":  {
                "auth_ref":  [
                    "r220"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.",
                            "label":  "Regulatory Assets",
                            "terseLabel":  "Total regulatory assets"
                            }
                        }
                    },
                "localname":  "RegulatoryAssets",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RegulatoryAssetsCurrent":  {
                "auth_ref":  [
                    "r220"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  5.0,
                        "parentTag":  "us-gaap_AssetsCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer.  Such costs are capitalized if they meet both of the following criteria: a.  It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b.  Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs.  If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost.",
                            "label":  "Regulatory Assets, Current",
                            "negatedTerseLabel":  "Less current regulatory assets",
                            "terseLabel":  "Regulatory assets, current"
                            }
                        }
                    },
                "localname":  "RegulatoryAssetsCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RegulatoryAssetsNoncurrent":  {
                "auth_ref":  [
                    "r220"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.",
                            "label":  "Regulatory Assets, Noncurrent",
                            "terseLabel":  "Regulatory assets, non-current"
                            }
                        }
                    },
                "localname":  "RegulatoryAssetsNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RegulatoryLiabilities":  {
                "auth_ref":  [
                    "r222"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period.",
                            "label":  "Regulatory Liabilities",
                            "terseLabel":  "Total regulatory liabilities"
                            }
                        }
                    },
                "localname":  "RegulatoryLiabilities",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RegulatoryLiabilitiesLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Line items represent financial concepts included in a table.  These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
                            "label":  "Regulatory Liabilities [Line Items]",
                            "terseLabel":  "Regulatory Liabilities [Line Items]"
                            }
                        }
                    },
                "localname":  "RegulatoryLiabilitiesLineItems",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RegulatoryLiabilityAxis":  {
                "auth_ref":  [
                    "r222"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by type of regulatory liability.",
                            "label":  "Regulatory Liability [Axis]",
                            "terseLabel":  "Regulatory Liability [Axis]"
                            }
                        }
                    },
                "localname":  "RegulatoryLiabilityAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RegulatoryLiabilityCurrent":  {
                "auth_ref":  [
                    "r222"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  6.0,
                        "parentTag":  "us-gaap_LiabilitiesCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The amount for the individual regulatory current liability as itemized in a table of regulatory current liabilities as of the end of the period.",
                            "label":  "Regulatory Liability, Current",
                            "negatedTerseLabel":  "Less current regulatory liabilities",
                            "terseLabel":  "Regulatory liabilities, current"
                            }
                        }
                    },
                "localname":  "RegulatoryLiabilityCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RegulatoryLiabilityDomain":  {
                "auth_ref":  [
                    "r222"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Rate action of a regulator resulting in accrual of costs or expenses.",
                            "label":  "Regulatory Liability [Domain]",
                            "terseLabel":  "Regulatory Liability [Domain]"
                            }
                        }
                    },
                "localname":  "RegulatoryLiabilityDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_RegulatoryLiabilityNoncurrent":  {
                "auth_ref":  [
                    "r22"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period.",
                            "label":  "Regulatory Liability, Noncurrent",
                            "terseLabel":  "Regulatory liabilities, non-current"
                            }
                        }
                    },
                "localname":  "RegulatoryLiabilityNoncurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets",
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RelatedPartyDomain":  {
                "auth_ref":  [
                    "r187"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Related parties include affiliates; other entities for which investments are accounted for by the equity method by the entity; trusts for benefit of employees; and principal owners, management, and members of immediate families.  It also may include other parties with which the entity may control or can significantly influence the management or operating policies of the other to an extent that one of the transacting parties might be prevented from fully pursuing its own separate interests.",
                            "label":  "Related Party [Domain]",
                            "terseLabel":  "Related Party [Domain]"
                            }
                        }
                    },
                "localname":  "RelatedPartyDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails",
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_RelatedPartyTransactionAxis":  {
                "auth_ref":  [
                    "r126",
                    "r181",
                    "r183"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by type of related party transaction.",
                            "label":  "Related Party Transaction [Axis]",
                            "terseLabel":  "Related Party Transaction [Axis]"
                            }
                        }
                    },
                "localname":  "RelatedPartyTransactionAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RelatedPartyTransactionDomain":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Transaction between related party.",
                            "label":  "Related Party Transaction [Domain]",
                            "terseLabel":  "Related Party Transaction [Domain]"
                            }
                        }
                    },
                "localname":  "RelatedPartyTransactionDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_RelatedPartyTransactionLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Line items represent financial concepts included in a table.  These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
                            "label":  "Related Party Transaction [Line Items]",
                            "terseLabel":  "Related Party Transaction [Line Items]"
                            }
                        }
                    },
                "localname":  "RelatedPartyTransactionLineItems",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RelatedPartyTransactionRate":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Identify the stated interest rate per the agreement, for example, leasing and debt arrangements between related parties.",
                            "label":  "Related Party Transaction, Rate",
                            "terseLabel":  "Related Party, Interest Rate"
                            }
                        }
                    },
                "localname":  "RelatedPartyTransactionRate",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "percentItemType"
                },
            "us-gaap_RelatedPartyTransactionsAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Related Party Transactions [Abstract]"
                            }
                        }
                    },
                "localname":  "RelatedPartyTransactionsAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RelatedPartyTransactionsByRelatedPartyAxis":  {
                "auth_ref":  [
                    "r126",
                    "r181",
                    "r183",
                    "r190",
                    "r191",
                    "r192",
                    "r193",
                    "r194",
                    "r195",
                    "r196",
                    "r197",
                    "r198",
                    "r199",
                    "r200",
                    "r201"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by type of related party.  Related parties include, but not limited to, affiliates; other entities for which investments are accounted for by the equity method by the entity; trusts for benefit of employees; and principal owners, management, and members of immediate families.  It also may include other parties with which the entity may control or can significantly influence the management or operating policies of the other to an extent that one of the transacting parties might be prevented from fully pursuing its own separate interests.",
                            "label":  "Related Party [Axis]",
                            "terseLabel":  "Related Party [Axis]"
                            }
                        }
                    },
                "localname":  "RelatedPartyTransactionsByRelatedPartyAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails",
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RelatedPartyTransactionsDisclosureTextBlock":  {
                "auth_ref":  [
                    "r187"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure for related party transactions.  Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.",
                            "label":  "Related Party Transactions Disclosure [Text Block]",
                            "terseLabel":  "Related-Party Transactions"
                            }
                        }
                    },
                "localname":  "RelatedPartyTransactionsDisclosureTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactions"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_RetainedEarningsAccumulatedDeficit":  {
                "auth_ref":  [
                    "r9",
                    "r100",
                    "r211"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  3.0,
                        "parentTag":  "us-gaap_StockholdersEquity",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
                            "label":  "Retained Earnings (Accumulated Deficit)",
                            "terseLabel":  "Retained earnings"
                            }
                        }
                    },
                "localname":  "RetainedEarningsAccumulatedDeficit",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RetainedEarningsMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
                            "label":  "Retained Earnings [Member]",
                            "terseLabel":  "Retained Earnings"
                            }
                        }
                    },
                "localname":  "RetainedEarningsMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_RetirementPlanTypeAxis":  {
                "auth_ref":  [
                    "r108",
                    "r109",
                    "r127",
                    "r128",
                    "r139"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by type of retirement benefit plan.  Includes, but is not limited to, retirement benefit arrangement for defined benefit pension and other postretirement plans, retirement benefit arrangement for defined contribution pension and other postretirement plans, and special and contractual termination benefits payable upon retirement.",
                            "label":  "Retirement Plan Type [Axis]",
                            "terseLabel":  "Retirement Plan Type [Axis]"
                            }
                        }
                    },
                "localname":  "RetirementPlanTypeAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RetirementPlanTypeDomain":  {
                "auth_ref":  [
                    "r108",
                    "r109",
                    "r127",
                    "r128",
                    "r139"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Type of plan designed to provide participants with retirement benefits.  Includes, but is not limited to, retirement benefit arrangement for defined benefit pension and other postretirement plans, retirement benefit arrangement for defined contribution pension and other postretirement plans, and special and contractual termination benefits payable upon retirement.",
                            "label":  "Retirement Plan Type [Domain]",
                            "terseLabel":  "Retirement Plan Type [Domain]"
                            }
                        }
                    },
                "localname":  "RetirementPlanTypeDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_RevenueFromContractWithCustomerAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Revenue from Contract with Customer [Abstract]"
                            }
                        }
                    },
                "localname":  "RevenueFromContractWithCustomerAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax":  {
                "auth_ref":  [
                    "r101",
                    "r102",
                    "r103"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/RevenueDetails":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_Revenues",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer.  Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.",
                            "label":  "Revenue from Contract with Customer, Excluding Assessed Tax",
                            "terseLabel":  "Revenue from contracts with customers"
                            }
                        }
                    },
                "localname":  "RevenueFromContractWithCustomerExcludingAssessedTax",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RevenueFromContractWithCustomerTextBlock":  {
                "auth_ref":  [
                    "r77",
                    "r107"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset.  Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer.  Excludes insurance and lease contracts.",
                            "label":  "Revenue from Contract with Customer [Text Block]",
                            "terseLabel":  "Revenue"
                            }
                        }
                    },
                "localname":  "RevenueFromContractWithCustomerTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/Revenue"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_RevenueFromRelatedParties":  {
                "auth_ref":  [
                    "r44",
                    "r217"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.",
                            "label":  "Revenue from Related Parties",
                            "terseLabel":  "Revenue"
                            }
                        }
                    },
                "localname":  "RevenueFromRelatedParties",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RevenueRecognitionPolicyTextBlock":  {
                "auth_ref":  [
                    "r69",
                    "r70",
                    "r71"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Disclosure of accounting policy for revenue recognition.  If the entity has different policies for different types of revenue transactions, the policy for each material type of transaction is generally disclosed.  If a sales transaction has multiple element arrangements (for example, delivery of multiple products, services or the rights to use assets) the disclosure may indicate the accounting policy for each unit of accounting as well as how units of accounting are determined and valued.  The disclosure may encompass important judgment as to appropriateness of principles related to recognition of revenue.  The disclosure also may indicate the entity's treatment of any unearned or deferred revenue that arises from the transaction.",
                            "label":  "Revenue Recognition, Policy [Policy Text Block]",
                            "terseLabel":  "Revenue Recognition"
                            }
                        }
                    },
                "localname":  "RevenueRecognitionPolicyTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/ManagementsStatementPolicies"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_RevenueSubjectToRefundMember":  {
                "auth_ref":  [
                    "r225"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Rate action of a regulator resulting in capitalization or accrual of revenue subject to refund.",
                            "label":  "Revenue Subject to Refund [Member]",
                            "terseLabel":  "TCJA revenue reserve"
                            }
                        }
                    },
                "localname":  "RevenueSubjectToRefundMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_Revenues":  {
                "auth_ref":  [
                    "r45",
                    "r82",
                    "r83",
                    "r88"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  1.0,
                        "parentTag":  "us-gaap_OperatingIncomeLoss",
                        "weight":  1.0
                        },
                    "http://www.blackhillscorp.com/role/RevenueDetails":  {
                        "order":  null,
                        "parentTag":  null,
                        "root":  true,
                        "weight":  null
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process.  Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).",
                            "label":  "Revenues",
                            "terseLabel":  "Revenues",
                            "totalLabel":  "Revenues"
                            }
                        }
                    },
                "localname":  "Revenues",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome",
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability":  {
                "auth_ref":  [
                    "r173",
                    "r178"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of increase in right-of-use asset obtained in exchange for operating lease liability.",
                            "label":  "Right-of-Use Asset Obtained in Exchange for Operating Lease Liability",
                            "terseLabel":  "Right of use assets obtained in exchange for lease obligations"
                            }
                        }
                    },
                "localname":  "RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesSupplementalCashFlowInformationDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock":  {
                "auth_ref":  [
                    "r26"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of the various types of trade accounts and notes receivable and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date.  Presentation is categorized by current, noncurrent and unclassified receivables.",
                            "label":  "Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]",
                            "terseLabel":  "Schedule of Accounts Receivable"
                            }
                        }
                    },
                "localname":  "ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/AccountsReceivableTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of supplemental cash flow information for the periods presented.",
                            "label":  "Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]",
                            "terseLabel":  "Schedule of Cash Flow, Supplemental Disclosures"
                            }
                        }
                    },
                "localname":  "ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable":  {
                "auth_ref":  [
                    "r127",
                    "r128",
                    "r129",
                    "r130",
                    "r138"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Disclosures about an individual defined benefit pension plan or an other postretirement defined benefit plan.  It may be appropriate to group certain similar plans.  Also includes schedule for fair value of plan assets by major categories of plan assets by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets or liabilities (Level 1), Significant other observable inputs (Level 2), and significant unobservable inputs (Level 3).",
                            "label":  "Schedule of Defined Benefit Plans Disclosures [Table]",
                            "terseLabel":  "Schedule of Defined Benefit Plans Disclosures [Table]"
                            }
                        }
                    },
                "localname":  "ScheduleOfDefinedBenefitPlansDisclosuresTable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_ScheduleOfNetBenefitCostsTableTextBlock":  {
                "auth_ref":  [
                    "r119"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments.",
                            "label":  "Schedule of Net Benefit Costs [Table Text Block]",
                            "terseLabel":  "Schedule of Net Benefit Costs"
                            }
                        }
                    },
                "localname":  "ScheduleOfNetBenefitCostsTableTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_ScheduleOfRegulatoryAssetsAndLiabilitiesTextBlock":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The entire disclosure for detailed information about regulatory assets and liabilities, including current and noncurrent assets created when regulatory agencies permit the deferral of costs to the balance sheet that would otherwise be required to appear on the company's income statement and would be charged against current expenses or revenues, as well as current and noncurrent liabilities created when regulatory agencies permit.",
                            "label":  "Schedule of Regulatory Assets and Liabilities [Text Block]",
                            "terseLabel":  "Regulatory Accounting"
                            }
                        }
                    },
                "localname":  "ScheduleOfRegulatoryAssetsAndLiabilitiesTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccounting"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_ScheduleOfRegulatoryAssetsTable":  {
                "auth_ref":  [
                    "r220",
                    "r221",
                    "r226"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "A table of assets that are created when regulatory agencies permit public utilities to defer certain costs that are included in rate-setting to the balance sheet.",
                            "label":  "Schedule of Regulatory Assets [Table]",
                            "terseLabel":  "Schedule of Regulatory Assets [Table]"
                            }
                        }
                    },
                "localname":  "ScheduleOfRegulatoryAssetsTable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryAssetsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_ScheduleOfRegulatoryAssetsTextBlock":  {
                "auth_ref":  [
                    "r220",
                    "r221",
                    "r226"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of assets that are created when regulatory agencies permit public utilities to defer certain costs included in rate-setting to the balance sheet.",
                            "label":  "Schedule of Regulatory Assets [Table Text Block]",
                            "terseLabel":  "Schedule of Regulatory Assets"
                            }
                        }
                    },
                "localname":  "ScheduleOfRegulatoryAssetsTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_ScheduleOfRegulatoryLiabilitiesTable":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "A table of liabilities that are created when regulatory agencies permit public utilities to defer recognition of certain revenues included in rate-setting.",
                            "label":  "Schedule of Regulatory Liabilities [Table]",
                            "terseLabel":  "Schedule of Regulatory Liabilities [Table]"
                            }
                        }
                    },
                "localname":  "ScheduleOfRegulatoryLiabilitiesTable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRegulatoryLiabilitiesDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_ScheduleOfRegulatoryLiabilitiesTextBlock":  {
                "auth_ref":  [
                    "r222"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Tabular disclosure of regulatory liabilities.  Detailed information about liabilities that result from rate actions of a regulator.  Rate actions of a regulator can impose a liability on a regulated enterprise resulting in a regulatory liability.",
                            "label":  "Schedule of Regulatory Liabilities [Table Text Block]",
                            "terseLabel":  "Schedule of Regulatory Liabilities"
                            }
                        }
                    },
                "localname":  "ScheduleOfRegulatoryLiabilitiesTextBlock",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingTables"
                    ],
                "xbrltype":  "textBlockItemType"
                },
            "us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable":  {
                "auth_ref":  [
                    "r73",
                    "r181",
                    "r183",
                    "r184",
                    "r185",
                    "r186"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Schedule of quantitative and qualitative information pertaining to related party transactions.  Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.",
                            "label":  "Schedule of Related Party Transactions, by Related Party [Table]",
                            "terseLabel":  "Schedule of Related Party Transactions, by Related Party [Table]"
                            }
                        }
                    },
                "localname":  "ScheduleOfRelatedPartyTransactionsByRelatedPartyTable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_StatementEquityComponentsAxis":  {
                "auth_ref":  [
                    "r24",
                    "r99"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by component of equity.",
                            "label":  "Equity Components [Axis]",
                            "terseLabel":  "Equity Components [Axis]"
                            }
                        }
                    },
                "localname":  "StatementEquityComponentsAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_StatementLineItems":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Line items represent financial concepts included in a table.  These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
                            "label":  "Statement [Line Items]",
                            "terseLabel":  "Statement [Line Items]"
                            }
                        }
                    },
                "localname":  "StatementLineItems",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_StatementOfCashFlowsAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Statement of Cash Flows [Abstract]"
                            }
                        }
                    },
                "localname":  "StatementOfCashFlowsAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_StatementOfFinancialPositionAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Statement of Financial Position [Abstract]"
                            }
                        }
                    },
                "localname":  "StatementOfFinancialPositionAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_StatementOfStockholdersEquityAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Statement of Stockholders' Equity [Abstract]"
                            }
                        }
                    },
                "localname":  "StatementOfStockholdersEquityAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_StatementTable":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Schedule reflecting a Statement of Income, Statement of Cash Flows, Statement of Financial Position, Statement of Shareholders' Equity and Other Comprehensive Income, or other statement as needed.",
                            "label":  "Statement [Table]",
                            "terseLabel":  "Statement [Table]"
                            }
                        }
                    },
                "localname":  "StatementTable",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_StockholdersEquity":  {
                "auth_ref":  [
                    "r6",
                    "r10",
                    "r11",
                    "r93"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets":  {
                        "order":  5.0,
                        "parentTag":  "us-gaap_LiabilitiesAndStockholdersEquity",
                        "weight":  1.0
                        }
                    },
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent.  The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest).  This excludes temporary equity and is sometimes called permanent equity.",
                            "label":  "Stockholders' Equity Attributable to Parent",
                            "totalLabel":  "Total stockholder\u2019s equity"
                            }
                        }
                    },
                "localname":  "StockholdersEquity",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest":  {
                "auth_ref":  [
                    "r148",
                    "r149",
                    "r152"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests.  Amount excludes temporary equity.  Alternate caption for the concept is permanent equity.",
                            "label":  "Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest",
                            "periodEndLabel":  "Stockholders' Equity - Ending Balance",
                            "periodStartLabel":  "Stockholders' Equity - Beginning Balance"
                            }
                        }
                    },
                "localname":  "StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_StockholdersEquityNumberOfSharesParValueAndOtherDisclosuresAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Stockholders' Equity, Number of Shares, Par Value and Other Disclosures [Abstract]",
                            "terseLabel":  "Stockholder\u2019s equity:"
                            }
                        }
                    },
                "localname":  "StockholdersEquityNumberOfSharesParValueAndOtherDisclosuresAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedBalanceSheets"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_StockholdersEquityOther":  {
                "auth_ref":  [
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "This element represents movements included in the statement of changes in stockholders' equity which are not separately disclosed or provided for elsewhere in the taxonomy.",
                            "label":  "Stockholders' Equity, Other",
                            "terseLabel":  "Other adjustments"
                            }
                        }
                    },
                "localname":  "StockholdersEquityOther",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCommonStockholdersEquity"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_SubsequentEventMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Identifies event that occurred after the balance sheet date but before financial statements are issued or available to be issued.",
                            "label":  "Subsequent Event [Member]",
                            "terseLabel":  "Subsequent Event"
                            }
                        }
                    },
                "localname":  "SubsequentEventMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_SubsequentEventTypeAxis":  {
                "auth_ref":  [
                    "r189"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by event that occurred after the balance sheet date but before financial statements are issued or available to be issued.",
                            "label":  "Subsequent Event Type [Axis]",
                            "terseLabel":  "Subsequent Event Type [Axis]"
                            }
                        }
                    },
                "localname":  "SubsequentEventTypeAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_SubsequentEventTypeDomain":  {
                "auth_ref":  [
                    "r189"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Event that occurred after the balance sheet date but before financial statements are issued or available to be issued.",
                            "label":  "Subsequent Event Type [Domain]",
                            "terseLabel":  "Subsequent Event Type [Domain]"
                            }
                        }
                    },
                "localname":  "SubsequentEventTypeDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RegulatoryAccountingRateReviewDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_SubsidiaryOfCommonParentMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Refers to an entity under the control of the same parent as another entity (that is, a sister company).",
                            "label":  "Subsidiary of Common Parent [Member]",
                            "terseLabel":  "Subsidiary of Common Parent"
                            }
                        }
                    },
                "localname":  "SubsidiaryOfCommonParentMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails",
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_SupplementalCashFlowElementsAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Supplemental Cash Flow Elements [Abstract]",
                            "terseLabel":  "Interest and Income Taxes Paid Net [Abstract]"
                            }
                        }
                    },
                "localname":  "SupplementalCashFlowElementsAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_SupplementalCashFlowInformationAbstract":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Supplemental Cash Flow Information [Abstract]"
                            }
                        }
                    },
                "localname":  "SupplementalCashFlowInformationAbstract",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "xbrltype":  "stringItemType"
                },
            "us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Plan designed to provide limited group of employees with supplemental retirement benefits, in addition to other pension benefits.  Includes, but is not limited to, defined benefit and defined contribution plans.",
                            "label":  "Supplemental Employee Retirement Plan [Member]",
                            "terseLabel":  "Supplemental Non-qualified Defined Benefit Plans"
                            }
                        }
                    },
                "localname":  "SupplementalEmployeeRetirementPlanDefinedBenefitMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/EmployeeBenefitPlansDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_TaxesExcludingIncomeAndExciseTaxes":  {
                "auth_ref":  [
                    "r50"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  4.0,
                        "parentTag":  "us-gaap_OperatingExpenses",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere.  These taxes could include production, real estate, personal property, and pump tax.",
                            "label":  "Taxes, Miscellaneous",
                            "terseLabel":  "Taxes - property"
                            }
                        }
                    },
                "localname":  "TaxesExcludingIncomeAndExciseTaxes",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_TimingOfTransferOfGoodOrServiceAxis":  {
                "auth_ref":  [
                    "r103",
                    "r106"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Information by timing of transfer of good or service to customer.",
                            "label":  "Timing of Transfer of Good or Service [Axis]",
                            "terseLabel":  "Timing of Transfer of Good or Service [Axis]"
                            }
                        }
                    },
                "localname":  "TimingOfTransferOfGoodOrServiceAxis",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "us-gaap_TimingOfTransferOfGoodOrServiceDomain":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Timing of transfer of good or service to customer.  Includes, but is not limited to, at point in time or over time.",
                            "label":  "Timing of Transfer of Good or Service [Domain]",
                            "terseLabel":  "Timing of Transfer of Good or Service [Domain]"
                            }
                        }
                    },
                "localname":  "TimingOfTransferOfGoodOrServiceDomain",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_TransferOfInvestments":  {
                "auth_ref":  [
                    "r65",
                    "r66",
                    "r67"
                    ],
                "crdr":  "credit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Value of investments transferred from the entity's investments in noncash transactions.",
                            "label":  "Transfer from Investments",
                            "negatedTerseLabel":  "Non-cash (decrease) to money pool notes receivable, net",
                            "terseLabel":  "Non-cash decrease to money pool notes receivable, net"
                            }
                        }
                    },
                "localname":  "TransferOfInvestments",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RelatedPartyTransactionsDetails",
                    "http://www.blackhillscorp.com/role/SupplementalDisclosureOfCashFlowInformationDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_TransferredOverTimeMember":  {
                "auth_ref":  [
                    "r103",
                    "r106"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Contract with customer in which good or service is transferred over time.",
                            "label":  "Transferred over Time [Member]",
                            "terseLabel":  "Services transferred over time"
                            }
                        }
                    },
                "localname":  "TransferredOverTimeMember",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/RevenueDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "us-gaap_UnbilledReceivablesCurrent":  {
                "auth_ref":  [
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/AccountsReceivableDetails":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_AccountsReceivableNetCurrent",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount received for services rendered and products shipped, but not yet billed, for non-contractual agreements due within one year or the normal operating cycle, if longer.",
                            "label":  "Unbilled Receivables, Current",
                            "terseLabel":  "Unbilled revenues"
                            }
                        }
                    },
                "localname":  "UnbilledReceivablesCurrent",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/AccountsReceivableDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization":  {
                "auth_ref":  [
                    "r46"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_NetCashProvidedByUsedInOperatingActivities",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of operating expense for depreciation and amortization of regulated operation.",
                            "label":  "Utilities Operating Expense, Depreciation and Amortization",
                            "terseLabel":  "Depreciation and amortization"
                            }
                        }
                    },
                "localname":  "UtilitiesOperatingExpenseDepreciationAndAmortization",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfCashFlows"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_UtilitiesOperatingExpenseMaintenanceAndOperations":  {
                "auth_ref":  [
                    "r46"
                    ],
                "calculation":  {
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome":  {
                        "order":  2.0,
                        "parentTag":  "us-gaap_OperatingExpenses",
                        "weight":  1.0
                        }
                    },
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of operating expense for routine plant maintenance, repairs and operations of regulated operation.",
                            "label":  "Utilities Operating Expense, Maintenance and Operations",
                            "terseLabel":  "Operations and maintenance"
                            }
                        }
                    },
                "localname":  "UtilitiesOperatingExpenseMaintenanceAndOperations",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/CondensedStatementsOfComprehensiveIncome"
                    ],
                "xbrltype":  "monetaryItemType"
                },
            "us-gaap_VariableLeaseCost":  {
                "auth_ref":  [
                    "r171",
                    "r178"
                    ],
                "crdr":  "debit",
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.",
                            "label":  "Variable Lease, Cost",
                            "terseLabel":  "Variable lease cost"
                            }
                        }
                    },
                "localname":  "VariableLeaseCost",
                "nsuri":  "http://fasb.org/us-gaap/2018-01-31",
                "presentation":  [
                    "http://www.blackhillscorp.com/role/LeasesLeaseCostsDetails"
                    ],
                "xbrltype":  "monetaryItemType"
                }
            },
        "unitCount":  6
        }
    },
"std_ref":  {
    "r0":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765"
        },
    "r1":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(b)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765"
        },
    "r10":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(30))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r100":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.3-04)",
        "Topic":  "505",
        "URI":  "http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770"
        },
    "r101":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "606",
        "URI":  "http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045"
        },
    "r102":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "606",
        "URI":  "http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045"
        },
    "r103":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "5",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "606",
        "URI":  "http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045"
        },
    "r104":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "8",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "606",
        "URI":  "http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045"
        },
    "r105":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "91",
        "Publisher":  "FASB",
        "Section":  "55",
        "SubTopic":  "10",
        "Subparagraph":  "(c)",
        "Topic":  "606",
        "URI":  "http://asc.fasb.org/extlink&oid=108792157&loc=SL49130690-203046-203046"
        },
    "r106":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "91",
        "Publisher":  "FASB",
        "Section":  "55",
        "SubTopic":  "10",
        "Subparagraph":  "(f)",
        "Topic":  "606",
        "URI":  "http://asc.fasb.org/extlink&oid=108792157&loc=SL49130690-203046-203046"
        },
    "r107":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "606",
        "URI":  "http://asc.fasb.org/topic&trid=49130388"
        },
    "r108":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "15",
        "SubTopic":  "10",
        "Subparagraph":  "(c)",
        "Topic":  "712",
        "URI":  "http://asc.fasb.org/extlink&oid=6410066&loc=d3e79218-111664"
        },
    "r109":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "15",
        "SubTopic":  "10",
        "Subparagraph":  "(d)",
        "Topic":  "712",
        "URI":  "http://asc.fasb.org/extlink&oid=6410066&loc=d3e79218-111664"
        },
    "r11":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(31))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r110":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "20",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=109237824&loc=d3e1703-114919"
        },
    "r111":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "20",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=109237824&loc=d3e1731-114919"
        },
    "r112":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(a)(1)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r113":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(a)(2)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r114":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(b)(3)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r115":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(c)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r116":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(d)(ii)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r117":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(d)(iv)(01)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r118":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(g)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r119":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(h)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r12":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(32))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r120":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(h)(1)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r121":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(h)(2)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r122":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(h)(3)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r123":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(h)(4)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r124":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(h)(5)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r125":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(i)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r126":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(n)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r127":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920"
        },
    "r128":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2410-114920"
        },
    "r129":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2417-114920"
        },
    "r13":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(4))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r130":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2439-114920"
        },
    "r131":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(a)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920"
        },
    "r132":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(a)(1)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920"
        },
    "r133":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(a)(2)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920"
        },
    "r134":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(a)(3)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920"
        },
    "r135":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(a)(4)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920"
        },
    "r136":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(a)(5)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920"
        },
    "r137":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(b)",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920"
        },
    "r138":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "17",
        "Publisher":  "FASB",
        "Section":  "55",
        "SubTopic":  "20",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921"
        },
    "r139":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "70",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942"
        },
    "r14":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.1)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r140":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "715",
        "URI":  "http://asc.fasb.org/topic&trid=2235017"
        },
    "r141":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "740",
        "URI":  "http://asc.fasb.org/extlink&oid=84176650&loc=d3e31917-109318"
        },
    "r142":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "740",
        "URI":  "http://asc.fasb.org/extlink&oid=84176650&loc=d3e31931-109318"
        },
    "r143":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "9",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "740",
        "URI":  "http://asc.fasb.org/extlink&oid=84176650&loc=d3e31958-109318"
        },
    "r144":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "9",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(b)",
        "Topic":  "740",
        "URI":  "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319"
        },
    "r145":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SAB Topic 6.I.7)",
        "Topic":  "740",
        "URI":  "http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817"
        },
    "r146":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "20",
        "Subparagraph":  "(a)",
        "Topic":  "740",
        "URI":  "http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324"
        },
    "r147":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "31",
        "Publisher":  "FASB",
        "Section":  "55",
        "SubTopic":  "20",
        "Subparagraph":  "(c)",
        "Topic":  "805",
        "URI":  "http://asc.fasb.org/extlink&oid=77890550&loc=d3e5419-128473"
        },
    "r148":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "15",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "810",
        "URI":  "http://asc.fasb.org/extlink&oid=108774443&loc=SL4568447-111683"
        },
    "r149":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "16",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "810",
        "URI":  "http://asc.fasb.org/extlink&oid=108774443&loc=SL4568740-111683"
        },
    "r15":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.12)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r150":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "19",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "810",
        "URI":  "http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683"
        },
    "r151":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1A",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(c),(3)",
        "Topic":  "810",
        "URI":  "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
        },
    "r152":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4I",
        "Publisher":  "FASB",
        "Section":  "55",
        "SubTopic":  "10",
        "Topic":  "810",
        "URI":  "http://asc.fasb.org/extlink&oid=84234705&loc=SL4590271-111686"
        },
    "r153":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4K",
        "Publisher":  "FASB",
        "Section":  "55",
        "SubTopic":  "10",
        "Topic":  "810",
        "URI":  "http://asc.fasb.org/extlink&oid=84234705&loc=SL4591552-111686"
        },
    "r154":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "810",
        "URI":  "http://asc.fasb.org/topic&trid=2197479"
        },
    "r155":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "c",
        "Topic":  "815",
        "URI":  "http://asc.fasb.org/extlink&oid=109980867&loc=d3e41638-113959"
        },
    "r156":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "820",
        "URI":  "http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258"
        },
    "r157":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6A",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "820",
        "URI":  "http://asc.fasb.org/extlink&oid=99377789&loc=SL6742756-110258"
        },
    "r158":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "820",
        "URI":  "http://asc.fasb.org/topic&trid=2155941"
        },
    "r159":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "825",
        "URI":  "http://asc.fasb.org/extlink&oid=75026489&loc=d3e13220-108610"
        },
    "r16":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.17)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r160":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "10",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "825",
        "URI":  "http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611"
        },
    "r161":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "11",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "825",
        "URI":  "http://asc.fasb.org/extlink&oid=109250915&loc=d3e13467-108611"
        },
    "r162":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "12",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "825",
        "URI":  "http://asc.fasb.org/extlink&oid=109250915&loc=d3e13476-108611"
        },
    "r163":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "230",
        "Topic":  "830",
        "URI":  "http://asc.fasb.org/extlink&oid=98513438&loc=d3e33268-110906"
        },
    "r164":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(b)",
        "Topic":  "835",
        "URI":  "http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391"
        },
    "r165":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "20",
        "Subparagraph":  "(a)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977"
        },
    "r166":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "20",
        "Subparagraph":  "(b)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977"
        },
    "r167":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "5",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "20",
        "Subparagraph":  "(c)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918643-209977"
        },
    "r168":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(a)(3)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980"
        },
    "r169":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980"
        },
    "r17":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.19(a)(5))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r170":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(b)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
        },
    "r171":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(d)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
        },
    "r172":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(g)(1)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
        },
    "r173":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(g)(2)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
        },
    "r174":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(g)(3)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
        },
    "r175":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(g)(4)",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
        },
    "r176":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
        },
    "r177":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980"
        },
    "r178":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "53",
        "Publisher":  "FASB",
        "Section":  "55",
        "SubTopic":  "20",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971"
        },
    "r179":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "SubTopic":  "20",
        "Topic":  "842",
        "URI":  "http://asc.fasb.org/subtopic&trid=77888251"
        },
    "r18":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.19(a))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r180":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(d)",
        "Topic":  "850",
        "URI":  "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864"
        },
    "r181":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "850",
        "URI":  "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864"
        },
    "r182":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "850",
        "URI":  "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39599-107864"
        },
    "r183":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "850",
        "URI":  "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864"
        },
    "r184":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "850",
        "URI":  "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864"
        },
    "r185":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "5",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "850",
        "URI":  "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39678-107864"
        },
    "r186":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "6",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "850",
        "URI":  "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39691-107864"
        },
    "r187":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "850",
        "URI":  "http://asc.fasb.org/topic&trid=2122745"
        },
    "r188":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "852",
        "URI":  "http://asc.fasb.org/extlink&oid=6918054&loc=d3e56071-112765"
        },
    "r189":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "855",
        "URI":  "http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662"
        },
    "r19":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.20)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r190":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "15",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(a)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e61929-109447"
        },
    "r191":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "15",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(b)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e61929-109447"
        },
    "r192":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "20",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(a)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62059-109447"
        },
    "r193":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "20",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(b)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62059-109447"
        },
    "r194":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "28",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(a)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62395-109447"
        },
    "r195":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "28",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(b)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62395-109447"
        },
    "r196":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "33",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(a)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62479-109447"
        },
    "r197":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "33",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(b)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62479-109447"
        },
    "r198":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "35A",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(a)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=SL6807758-109447"
        },
    "r199":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "35A",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(b)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=SL6807758-109447"
        },
    "r2":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765"
        },
    "r20":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.21)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r200":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "8",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(c)(1)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e61872-109447"
        },
    "r201":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "8",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "235",
        "Subparagraph":  "(c)(2)",
        "Topic":  "932",
        "URI":  "http://asc.fasb.org/extlink&oid=68064819&loc=d3e61872-109447"
        },
    "r202":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.9-03(11))",
        "Topic":  "942",
        "URI":  "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
        },
    "r203":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.9-03(16))",
        "Topic":  "942",
        "URI":  "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
        },
    "r204":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.9-03(23))",
        "Topic":  "942",
        "URI":  "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
        },
    "r205":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.9-03(7))",
        "Topic":  "942",
        "URI":  "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
        },
    "r206":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.9-03.17)",
        "Topic":  "942",
        "URI":  "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
        },
    "r207":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "220",
        "Subparagraph":  "(SX 210.9-04.10)",
        "Topic":  "942",
        "URI":  "http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260"
        },
    "r208":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.7-03(5))",
        "Topic":  "944",
        "URI":  "http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910"
        },
    "r209":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.7-03(a)(12))",
        "Topic":  "944",
        "URI":  "http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910"
        },
    "r21":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.22)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r210":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.7-03(a)(16))",
        "Topic":  "944",
        "URI":  "http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910"
        },
    "r211":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.7-03(a)(23)(a)(4))",
        "Topic":  "944",
        "URI":  "http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910"
        },
    "r212":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.7-03(a)(25))",
        "Topic":  "944",
        "URI":  "http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910"
        },
    "r213":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.7-03(a)(5))",
        "Topic":  "944",
        "URI":  "http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910"
        },
    "r214":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.7-03.(a),19)",
        "Topic":  "944",
        "URI":  "http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910"
        },
    "r215":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.7-03.17)",
        "Topic":  "944",
        "URI":  "http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910"
        },
    "r216":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "210",
        "Subparagraph":  "(SX 210.6-04(6))",
        "Topic":  "946",
        "URI":  "http://asc.fasb.org/extlink&oid=6488278&loc=d3e603758-122996"
        },
    "r217":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "220",
        "Subparagraph":  "(SX 210.6-07.1(c))",
        "Topic":  "946",
        "URI":  "http://asc.fasb.org/extlink&oid=114873854&loc=SL114874292-224272"
        },
    "r218":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "360",
        "Subparagraph":  "(SX 210.12-28)",
        "Topic":  "970",
        "URI":  "http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024"
        },
    "r219":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "25",
        "SubTopic":  "340",
        "Topic":  "980",
        "URI":  "http://asc.fasb.org/extlink&oid=77907324&loc=d3e43603-110378"
        },
    "r22":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.24)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r220":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "340",
        "Topic":  "980",
        "URI":  "http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382"
        },
    "r221":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "340",
        "Topic":  "980",
        "URI":  "http://asc.fasb.org/extlink&oid=6499975&loc=d3e44264-110382"
        },
    "r222":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "25",
        "SubTopic":  "405",
        "Topic":  "980",
        "URI":  "http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394"
        },
    "r223":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "410",
        "Subparagraph":  "(SAB Topic 10.F)",
        "Topic":  "980",
        "URI":  "http://asc.fasb.org/extlink&oid=6228715&loc=d3e660557-123036"
        },
    "r224":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "40",
        "SubTopic":  "470",
        "Topic":  "980",
        "URI":  "http://asc.fasb.org/extlink&oid=6500971&loc=d3e49673-110406"
        },
    "r225":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "605",
        "Topic":  "980",
        "URI":  "http://asc.fasb.org/extlink&oid=109242873&loc=d3e50972-110412"
        },
    "r226":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "715",
        "Topic":  "980",
        "URI":  "http://asc.fasb.org/extlink&oid=6501251&loc=d3e52485-110419"
        },
    "r227":  {
        "Name":  "Form 10-Q",
        "Number":  "240",
        "Publisher":  "SEC",
        "Section":  "13",
        "Subsection":  "a-13"
        },
    "r228":  {
        "Name":  "Forms 10-K, 10-Q, 20-F",
        "Number":  "240",
        "Publisher":  "SEC",
        "Section":  "13",
        "Subsection":  "a-1-"
        },
    "r229":  {
        "Name":  "Regulation 12B",
        "Number":  "240",
        "Publisher":  "SEC",
        "Section":  "12",
        "Subsection":  "b-2"
        },
    "r23":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.25)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r230":  {
        "Name":  "Regulation S-T",
        "Number":  "232",
        "Publisher":  "SEC",
        "Section":  "405"
        },
    "r24":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.29-31)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r25":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.3(a)(2))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r26":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.3,4)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r27":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.4)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r28":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.6(a))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r29":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.8)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r3":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=82887183&loc=d3e6801-107765"
        },
    "r30":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02.9)",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r31":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "10A",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(i-k)",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580"
        },
    "r32":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "10A",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580"
        },
    "r33":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "11",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=d3e637-108580"
        },
    "r34":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "12",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=d3e640-108580"
        },
    "r35":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "14",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=d3e681-108580"
        },
    "r36":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "14A",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=SL7669686-108580"
        },
    "r37":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "15",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=d3e689-108580"
        },
    "r38":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "17A",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=SL34724391-108580"
        },
    "r39":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "17B",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=SL34724394-108580"
        },
    "r4":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(22))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r40":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1A",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(b)",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=SL7669619-108580"
        },
    "r41":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1A",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(c)",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=SL7669619-108580"
        },
    "r42":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1B",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(b)",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=114867106&loc=SL7669625-108580"
        },
    "r43":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "15",
        "Publisher":  "FASB",
        "Section":  "55",
        "SubTopic":  "10",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=109228884&loc=d3e1436-108581"
        },
    "r44":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-03.1(e))",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227"
        },
    "r45":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-03.1)",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227"
        },
    "r46":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-03.2(b))",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227"
        },
    "r47":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-03.2)",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227"
        },
    "r48":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-03.7(b))",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227"
        },
    "r49":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-03.7)",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227"
        },
    "r5":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(24))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r50":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-03.9)",
        "Topic":  "220",
        "URI":  "http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227"
        },
    "r51":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "12",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585"
        },
    "r52":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "13",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(c)",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585"
        },
    "r53":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "13",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585"
        },
    "r54":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "14",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(b)",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585"
        },
    "r55":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "17",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(d)",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3367-108585"
        },
    "r56":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "24",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3521-108585"
        },
    "r57":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "25",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(e)",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3536-108585"
        },
    "r58":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "25",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(g)",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3536-108585"
        },
    "r59":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "25",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3536-108585"
        },
    "r6":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(29))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r60":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "28",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585"
        },
    "r61":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "28",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Subparagraph":  "(b)",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585"
        },
    "r62":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "28",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585"
        },
    "r63":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=109223946&loc=d3e3044-108585"
        },
    "r64":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4297-108586"
        },
    "r65":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586"
        },
    "r66":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586"
        },
    "r67":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "5",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586"
        },
    "r68":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "230",
        "URI":  "http://asc.fasb.org/topic&trid=2134446"
        },
    "r69":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "235",
        "URI":  "http://asc.fasb.org/extlink&oid=84158767&loc=d3e18726-107790"
        },
    "r7":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(3))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r70":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "235",
        "URI":  "http://asc.fasb.org/extlink&oid=84158767&loc=d3e18780-107790"
        },
    "r71":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "235",
        "URI":  "http://asc.fasb.org/extlink&oid=84158767&loc=d3e18823-107790"
        },
    "r72":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.4-08(h))",
        "Topic":  "235",
        "URI":  "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690"
        },
    "r73":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.4-08(k))",
        "Topic":  "235",
        "URI":  "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690"
        },
    "r74":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.4-08.(h)(1)(i))",
        "Topic":  "235",
        "URI":  "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690"
        },
    "r75":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.4-08.(k)(1))",
        "Topic":  "235",
        "URI":  "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690"
        },
    "r76":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.12-04(a))",
        "Topic":  "235",
        "URI":  "http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690"
        },
    "r77":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "235",
        "URI":  "http://asc.fasb.org/topic&trid=2122369"
        },
    "r78":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "11",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "250",
        "URI":  "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794"
        },
    "r79":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "250",
        "URI":  "http://asc.fasb.org/topic&trid=2122394"
        },
    "r8":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(30)(a)(1))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r80":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "11",
        "Publisher":  "FASB",
        "Section":  "45",
        "SubTopic":  "10",
        "Topic":  "260",
        "URI":  "http://asc.fasb.org/extlink&oid=109260490&loc=d3e1377-109256"
        },
    "r81":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "275",
        "URI":  "http://asc.fasb.org/topic&trid=2134479"
        },
    "r82":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "22",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "280",
        "URI":  "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
        },
    "r83":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "22",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(b)",
        "Topic":  "280",
        "URI":  "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
        },
    "r84":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "22",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(c)",
        "Topic":  "280",
        "URI":  "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
        },
    "r85":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "22",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(e)",
        "Topic":  "280",
        "URI":  "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
        },
    "r86":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "22",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(h)",
        "Topic":  "280",
        "URI":  "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
        },
    "r87":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "22",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "280",
        "URI":  "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
        },
    "r88":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "32",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "280",
        "URI":  "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599"
        },
    "r89":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "42",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "280",
        "URI":  "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9054-108599"
        },
    "r9":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SX 210.5-02(30)(a)(3))",
        "Topic":  "210",
        "URI":  "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
        },
    "r90":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "11",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "310",
        "URI":  "http://asc.fasb.org/extlink&oid=84173941&loc=d3e5162-111524"
        },
    "r91":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "3",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "310",
        "URI":  "http://asc.fasb.org/extlink&oid=84173941&loc=d3e5066-111524"
        },
    "r92":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "310",
        "URI":  "http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524"
        },
    "r93":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "S99",
        "SubTopic":  "10",
        "Subparagraph":  "(SAB Topic 4.E)",
        "Topic":  "310",
        "URI":  "http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707"
        },
    "r94":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "35",
        "SubTopic":  "10",
        "Topic":  "330",
        "URI":  "http://asc.fasb.org/extlink&oid=68049868&loc=d3e3927-108312"
        },
    "r95":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "440",
        "URI":  "http://asc.fasb.org/topic&trid=2144648"
        },
    "r96":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Topic":  "450",
        "URI":  "http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349"
        },
    "r97":  {
        "Name":  "Accounting Standards Codification",
        "Publisher":  "FASB",
        "Topic":  "450",
        "URI":  "http://asc.fasb.org/topic&trid=2127136"
        },
    "r98":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "4",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "20",
        "Subparagraph":  "(b)(3)",
        "Topic":  "470",
        "URI":  "http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870"
        },
    "r99":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "2",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Topic":  "505",
        "URI":  "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644"
        }
    },
"version":  "2.1"
}

Top
Filing Submission 0000012400-19-000012   –   Alternative Formats (Word / Rich Text, HTML, Plain Text, et al.)

Copyright © 2024 Fran Finnegan & Company LLC – All Rights Reserved.
AboutPrivacyRedactionsHelp — Tue., May 7, 12:30:17.3am ET