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Willdan Group, Inc. – ‘10-Q’ for 7/3/20 – ‘JSON’

On:  Thursday, 8/6/20, at 9:13pm ET   ·   As of:  8/7/20   ·   For:  7/3/20   ·   Accession #:  1558370-20-9776   ·   File #:  1-33076

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

 8/07/20  Willdan Group, Inc.               10-Q        7/03/20   69:10M                                    Toppan Merrill Bridge/FA

Quarterly Report   —   Form 10-Q
Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-Q        Quarterly Report                                    HTML   1.53M 
 2: EX-31.1     Certification -- §302 - SOA'02                      HTML     24K 
 3: EX-31.2     Certification -- §302 - SOA'02                      HTML     25K 
 4: EX-32.1     Certification -- §906 - SOA'02                      HTML     24K 
11: R1          Document and Entity Information                     HTML     73K 
12: R2          Condensed Consolidated Balance Sheets               HTML    120K 
13: R3          Condensed Consolidated Balance Sheets               HTML     39K 
                (Parenthetical)                                                  
14: R4          Condensed Consolidated Statements of Comprehensive  HTML    104K 
                Income                                                           
15: R5          Condensed Consolidated Statements of Stockholders'  HTML     92K 
                Equity                                                           
16: R6          Condensed Consolidated Statements of Cash Flows     HTML    118K 
17: R7          Organization and Operations of the Company          HTML     45K 
18: R8          Recent Accounting Pronouncements                    HTML     32K 
19: R9          Revenues                                            HTML     50K 
20: R10         Supplemental Financial Statement Data               HTML    128K 
21: R11         Derivative Financial Instruments                    HTML     60K 
22: R12         Debt Obligations                                    HTML     53K 
23: R13         Leases                                              HTML    150K 
24: R14         Commitments and Variable Interest Entities          HTML     26K 
25: R15         Segment and Geographical Information                HTML    326K 
26: R16         Income Taxes                                        HTML     30K 
27: R17         Earnings Per Share (Eps)                            HTML     56K 
28: R18         Business Combinations                               HTML    153K 
29: R19         Contingencies                                       HTML     24K 
30: R20         Subsequent Events                                   HTML     22K 
31: R21         Organization and Operations of the Company          HTML     84K 
                (Policies)                                                       
32: R22         Revenues (Tables)                                   HTML     29K 
33: R23         Supplemental Financial Statement Data (Tables)      HTML    132K 
34: R24         Derivative Financial Instruments (Tables)           HTML     58K 
35: R25         Debt Obligations (Tables)                           HTML     41K 
36: R26         Leases (Tables)                                     HTML    179K 
37: R27         Segment and Geographical Information (Tables)       HTML    320K 
38: R28         Earnings Per Share (Eps) (Tables)                   HTML     54K 
39: R29         Business Combinations (Tables)                      HTML    148K 
40: R30         ORGANIZATION AND OPERATIONS OF THE COMPANY -        HTML     45K 
                Management's Plans in Response to Covid-19 and                   
                Fiscal Years (Details)                                           
41: R31         Revenues (Details)                                  HTML     44K 
42: R32         SUPPLEMENTAL FINANCIAL STATEMENT DATA - Equipment   HTML     45K 
                And Leasehold Improvements, Net (Details)                        
43: R33         SUPPLEMENTAL FINANCIAL STATEMENT DATA - Accrued     HTML     35K 
                Liabilities (Details)                                            
44: R34         SUPPLEMENTAL FINANCIAL STATEMENT DATA - Carrying    HTML     29K 
                Value of Goodwill by Reporting Unit (Details)                    
45: R35         SUPPLEMENTAL FINANCIAL STATEMENT DATA - Gross       HTML     48K 
                Amount and Amortization (Details)                                
46: R36         Derivative Financial Instruments (Details)          HTML     33K 
47: R37         Derivative Financial Instruments - Fair Values      HTML     27K 
                (Details)                                                        
48: R38         DERIVATIVE FINANCIAL INSTRUMENTS - Others           HTML     25K 
                (Details)                                                        
49: R39         DERIVATIVE FINANCIAL INSTRUMENTS -Accumulated       HTML     42K 
                balances and reporting period activities (Details)               
50: R40         Debt Obligations (Details)                          HTML     38K 
51: R41         Debt Obligations - Line of credit (Details)         HTML     76K 
52: R42         DEBT OBLIGATIONS - Debt Agreements (Details)        HTML     72K 
53: R43         LEASES - Change in accounting policy (Details)      HTML     34K 
54: R44         LEASES - Lease expense (Details)                    HTML     29K 
55: R45         LEASES - Impact of Adoption (Details)               HTML     70K 
56: R46         LEASES - Supplemental cash flow information         HTML     28K 
                (Details)                                                        
57: R47         LEASES - Maturities of lease liabilities (Details)  HTML     66K 
58: R48         COMMITMENTS AND VARIABLE INTEREST ENTITIES -        HTML     36K 
                Employee Benefit Plans (Details)                                 
59: R49         Segment and Geographical Information (Details)      HTML     80K 
60: R50         Segment and Geographical Information -              HTML     63K 
                Disaggregation of Revenue (Details)                              
61: R51         SEGMENT AND GEOGRAPHICAL INFORMATION -              HTML     44K 
                Concentration risk (Details)                                     
62: R52         Income Taxes (Details)                              HTML     34K 
63: R53         Earnings Per Share (Eps) (Details)                  HTML     54K 
64: R54         Business Combinations (Details)                     HTML     43K 
65: R55         Business Combinations (Acquisitions) (Details)      HTML    196K 
67: XML         IDEA XML File -- Filing Summary                      XML    122K 
10: XML         XBRL Instance -- wldn-20200703x10q_htm               XML   3.20M 
66: EXCEL       IDEA Workbook of Financial Reports                  XLSX    105K 
 6: EX-101.CAL  XBRL Calculations -- wldn-20200703_cal               XML    188K 
 7: EX-101.DEF  XBRL Definitions -- wldn-20200703_def                XML    554K 
 8: EX-101.LAB  XBRL Labels -- wldn-20200703_lab                     XML   1.32M 
 9: EX-101.PRE  XBRL Presentations -- wldn-20200703_pre              XML    962K 
 5: EX-101.SCH  XBRL Schema -- wldn-20200703                         XSD    155K 
68: JSON        XBRL Instance as JSON Data -- MetaLinks              361±   523K 
69: ZIP         XBRL Zipped Folder -- 0001558370-20-009776-xbrl      Zip    296K 


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                    "en-US":  {
                        "role":  {
                            "documentation":  "Boolean flag that is true only for a form used as a transition report.",
                            "label":  "Document Transition Report"
                            }
                        }
                    },
                "localname":  "DocumentTransitionReport",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "DocumentType",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityAddressAddressLine1",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_EntityAddressAddressLine2":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Address Line 2 such as Street or Suite number",
                            "label":  "Entity Address, Address Line Two"
                            }
                        }
                    },
                "localname":  "EntityAddressAddressLine2",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_EntityAddressCityOrTown":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Name of the City or Town",
                            "label":  "Entity Address, City or Town"
                            }
                        }
                    },
                "localname":  "EntityAddressCityOrTown",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_EntityAddressPostalZipCode":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Code for the postal or zip code",
                            "label":  "Entity Address, Postal Zip Code"
                            }
                        }
                    },
                "localname":  "EntityAddressPostalZipCode",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_EntityAddressStateOrProvince":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Name of the state or province.",
                            "label":  "Entity Address, State or Province"
                            }
                        }
                    },
                "localname":  "EntityAddressStateOrProvince",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "stateOrProvinceItemType"
                },
            "dei_EntityCentralIndexKey":  {
                "auth_ref":  [
                    "r479"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityCentralIndexKey",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityCommonStockSharesOutstanding",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityCurrentReportingStatus",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "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/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DisclosureBusinessCombinationsAcquisitionsDetails",
                    "http://www.willdan.com/role/DisclosureBusinessCombinationsDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "dei_EntityEmergingGrowthCompany":  {
                "auth_ref":  [
                    "r479"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Indicate if registrant meets the emerging growth company criteria.",
                            "label":  "Entity Emerging Growth Company"
                            }
                        }
                    },
                "localname":  "EntityEmergingGrowthCompany",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityFileNumber",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "fileNumberItemType"
                },
            "dei_EntityFilerCategory":  {
                "auth_ref":  [
                    "r479"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityFilerCategory",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityIncorporationStateCountryCode",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "edgarStateCountryItemType"
                },
            "dei_EntityInteractiveDataCurrent":  {
                "auth_ref":  [
                    "r480"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityInteractiveDataCurrent",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "yesNoItemType"
                },
            "dei_EntityRegistrantName":  {
                "auth_ref":  [
                    "r479"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityRegistrantName",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_EntityShellCompany":  {
                "auth_ref":  [
                    "r479"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityShellCompany",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "booleanItemType"
                },
            "dei_EntitySmallBusiness":  {
                "auth_ref":  [
                    "r479"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Indicates that the company is a Smaller Reporting Company (SRC).",
                            "label":  "Entity Small Business"
                            }
                        }
                    },
                "localname":  "EntitySmallBusiness",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "booleanItemType"
                },
            "dei_EntityTaxIdentificationNumber":  {
                "auth_ref":  [
                    "r479"
                    ],
                "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"
                            }
                        }
                    },
                "localname":  "EntityTaxIdentificationNumber",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "employerIdItemType"
                },
            "dei_LegalEntityAxis":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "The set of legal entities associated with a report.",
                            "label":  "Legal Entity [Axis]"
                            }
                        }
                    },
                "localname":  "LegalEntityAxis",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DisclosureBusinessCombinationsAcquisitionsDetails",
                    "http://www.willdan.com/role/DisclosureBusinessCombinationsDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "dei_LocalPhoneNumber":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Local phone number for entity.",
                            "label":  "Local Phone Number"
                            }
                        }
                    },
                "localname":  "LocalPhoneNumber",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "normalizedStringItemType"
                },
            "dei_Security12bTitle":  {
                "auth_ref":  [
                    "r475"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Title of a 12(b) registered security.",
                            "label":  "Title of 12(b) Security"
                            }
                        }
                    },
                "localname":  "Security12bTitle",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "securityTitleItemType"
                },
            "dei_SecurityExchangeName":  {
                "auth_ref":  [
                    "r476"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Name of the Exchange on which a security is registered.",
                            "label":  "Security Exchange Name"
                            }
                        }
                    },
                "localname":  "SecurityExchangeName",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "edgarExchangeCodeItemType"
                },
            "dei_TradingSymbol":  {
                "auth_ref":  [
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "documentation":  "Trading symbol of an instrument as listed on an exchange.",
                            "label":  "Trading Symbol"
                            }
                        }
                    },
                "localname":  "TradingSymbol",
                "nsuri":  "http://xbrl.sec.gov/dei/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DocumentDocumentAndEntityInformation"
                    ],
                "xbrltype":  "tradingSymbolItemType"
                },
            "srt_ConsolidationItemsAxis":  {
                "auth_ref":  [
                    "r150",
                    "r163",
                    "r164",
                    "r165",
                    "r166",
                    "r168",
                    "r170",
                    "r174"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Consolidation Items [Axis]"
                            }
                        }
                    },
                "localname":  "ConsolidationItemsAxis",
                "nsuri":  "http://fasb.org/srt/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DisclosureSegmentAndGeographicalInformationDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "srt_ConsolidationItemsDomain":  {
                "auth_ref":  [
                    "r150",
                    "r163",
                    "r164",
                    "r165",
                    "r166",
                    "r168",
                    "r170",
                    "r174"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Consolidation Items [Domain]",
                            "terseLabel":  "Consolidation Items [Domain]"
                            }
                        }
                    },
                "localname":  "ConsolidationItemsDomain",
                "nsuri":  "http://fasb.org/srt/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DisclosureSegmentAndGeographicalInformationDetails"
                    ],
                "xbrltype":  "domainItemType"
                },
            "srt_MajorCustomersAxis":  {
                "auth_ref":  [
                    "r181",
                    "r240",
                    "r245",
                    "r454"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Customer [Axis]"
                            }
                        }
                    },
                "localname":  "MajorCustomersAxis",
                "nsuri":  "http://fasb.org/srt/2020-01-31",
                "presentation":  [
                    "http://www.willdan.com/role/DisclosureSegmentAndGeographicalInformationConcentrationRiskDetails",
                    "http://www.willdan.com/role/DisclosureSegmentAndGeographicalInformationDisaggregationOfRevenueDetails"
                    ],
                "xbrltype":  "stringItemType"
                },
            "srt_MaximumMember":  {
                "auth_ref":  [
                    "r264",
                    "r267",
                    "r410",
                    "r411",
                    "r412",
                    "r413",
                    "r414",
                    "r415",
                    "r416",
                    "r452",
                    "r455"
                    ],
                "lang":  {
                    "en-US":  {
                        "role":  {
                            "label":  "Maximum [Member]",
                            "terseLabel":  "Maximum"
                            }
                        }
                    },
                "localname":  "MaximumMember",
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        "SubTopic":  "10",
        "Subparagraph":  "(a)",
        "Topic":  "250",
        "URI":  "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794"
        },
    "r99":  {
        "Name":  "Accounting Standards Codification",
        "Paragraph":  "1",
        "Publisher":  "FASB",
        "Section":  "50",
        "SubTopic":  "10",
        "Subparagraph":  "(b)(1)",
        "Topic":  "250",
        "URI":  "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794"
        }
    },
"version":  "2.1"
}


7 Previous Filings that this Filing References

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

 5/08/20  Willdan Group, Inc.               10-Q        4/03/20   69:10M                                    Toppan Merrill Bridge/FA
 3/06/20  Willdan Group, Inc.               10-K       12/27/19  101:18M                                    Toppan Merrill Bridge/FA
11/01/19  Willdan Group, Inc.               10-Q        9/27/19   80:14M                                    Toppan Merrill Bridge/FA
 8/03/17  Willdan Group, Inc.               8-K:2,3,7,9 7/28/17    4:1M                                     Toppan Merrill/FA
 8/13/09  Willdan Group, Inc.               10-Q        7/03/09    5:994K                                   Toppan Merrill/FA
 9/19/06  Willdan Group, Inc.               S-1/A¶                 8:1.3M                                   Toppan Merrill-FA
 8/09/06  Willdan Group, Inc.               S-1                   23:1.9M                                   Toppan Merrill-FA
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