| | | | | | | | | | | | | | | | | | | | | |
<?xml version="1.0" encoding="windows-1252"?> |
<FilingSummary> |
| <Version> 3.8.0.1 </Version> |
| <ProcessingTime/> |
| <ReportFormat> html </ReportFormat> |
| <ContextCount> 1552 </ContextCount> |
| <ElementCount> 946 </ElementCount> |
| <EntityCount> 1 </EntityCount> |
| <FootnotesReported> true </FootnotesReported> |
| <SegmentCount> 316 </SegmentCount> |
| <ScenarioCount> 0 </ScenarioCount> |
| <TuplesReported> false </TuplesReported> |
| <UnitCount> 12 </UnitCount> |
| <MyReports> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R1.htm </HtmlFileName> |
| | | <LongName> 0001000 - Document - Document and Entity Information </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DocumentAndEntityInformation </Role> |
| | | <ShortName> Document and Entity Information </ShortName> |
| | | <MenuCategory> Cover </MenuCategory> |
| | | <Position> 1 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R2.htm </HtmlFileName> |
| | | <LongName> 1002000 - Statement - Consolidated Income Statement </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ConsolidatedIncomeStatement </Role> |
| | | <ShortName> Consolidated Income Statement </ShortName> |
| | | <MenuCategory> Statements </MenuCategory> |
| | | <Position> 2 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R3.htm </HtmlFileName> |
| | | <LongName> 1002501 - Statement - Consolidated Income Statement (Parenthetical) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ConsolidatedIncomeStatementParenthetical </Role> |
| | | <ShortName> Consolidated Income Statement (Parenthetical) </ShortName> |
| | | <MenuCategory> Statements </MenuCategory> |
| | | <Position> 3 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R4.htm </HtmlFileName> |
| | | <LongName> 1003000 - Statement - Consolidated Comprehensive Income Statement </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ConsolidatedComprehensiveIncomeStatement </Role> |
| | | <ShortName> Consolidated Comprehensive Income Statement </ShortName> |
| | | <MenuCategory> Statements </MenuCategory> |
| | | <Position> 4 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R5.htm </HtmlFileName> |
| | | <LongName> 1003501 - Statement - Consolidated Comprehensive Income Statement (Parenthetical) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ConsolidatedComprehensiveIncomeStatementParenthetical </Role> |
| | | <ShortName> Consolidated Comprehensive Income Statement (Parenthetical) </ShortName> |
| | | <MenuCategory> Statements </MenuCategory> |
| | | <Position> 5 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R6.htm </HtmlFileName> |
| | | <LongName> 1004000 - Statement - Consolidated Balance Sheet </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ConsolidatedBalanceSheet </Role> |
| | | <ShortName> Consolidated Balance Sheet </ShortName> |
| | | <MenuCategory> Statements </MenuCategory> |
| | | <Position> 6 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R7.htm </HtmlFileName> |
| | | <LongName> 1004501 - Statement - Consolidated Balance Sheet (Parenthetical) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ConsolidatedBalanceSheetParenthetical </Role> |
| | | <ShortName> Consolidated Balance Sheet (Parenthetical) </ShortName> |
| | | <MenuCategory> Statements </MenuCategory> |
| | | <Position> 7 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R8.htm </HtmlFileName> |
| | | <LongName> 1005000 - Statement - Consolidated Statement of Cash Flows </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ConsolidatedStatementOfCashFlows </Role> |
| | | <ShortName> Consolidated Statement of Cash Flows </ShortName> |
| | | <MenuCategory> Statements </MenuCategory> |
| | | <Position> 8 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R9.htm </HtmlFileName> |
| | | <LongName> 1006000 - Statement - Consolidated Statement of Changes in Equity </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ConsolidatedStatementOfChangesInEquity </Role> |
| | | <ShortName> Consolidated Statement of Changes in Equity </ShortName> |
| | | <MenuCategory> Statements </MenuCategory> |
| | | <Position> 9 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R10.htm </HtmlFileName> |
| | | <LongName> 1006501 - Statement - Consolidated Statement of Changes in Equity (Parenthetical) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ConsolidatedStatementOfChangesInEquityParenthetical </Role> |
| | | <ShortName> Consolidated Statement of Changes in Equity (Parenthetical) </ShortName> |
| | | <MenuCategory> Statements </MenuCategory> |
| | | <Position> 10 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R11.htm </HtmlFileName> |
| | | <LongName> 2101100 - Disclosure - Summary of significant accounting and reporting policies </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SummaryOfSignificantAccountingAndReportingPolicies </Role> |
| | | <ShortName> Summary of significant accounting and reporting policies </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 11 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R12.htm </HtmlFileName> |
| | | <LongName> 2102100 - Disclosure - Accounting change and new accounting guidance </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/AccountingChangeAndNewAccountingGuidance </Role> |
| | | <ShortName> Accounting change and new accounting guidance </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 12 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R13.htm </HtmlFileName> |
| | | <LongName> 2103100 - Disclosure - Acquisitions </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/Acquisitions </Role> |
| | | <ShortName> Acquisitions </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 13 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R14.htm </HtmlFileName> |
| | | <LongName> 2104100 - Disclosure - Securities </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/Securities </Role> |
| | | <ShortName> Securities </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 14 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R15.htm </HtmlFileName> |
| | | <LongName> 2105100 - Disclosure - Loans and asset quality </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQuality </Role> |
| | | <ShortName> Loans and asset quality </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 15 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R16.htm </HtmlFileName> |
| | | <LongName> 2106100 - Disclosure - Goodwill and intangible assets </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/GoodwillAndIntangibleAssets </Role> |
| | | <ShortName> Goodwill and intangible assets </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 16 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R17.htm </HtmlFileName> |
| | | <LongName> 2107100 - Disclosure - Other assets </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/OtherAssets </Role> |
| | | <ShortName> Other assets </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 17 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R18.htm </HtmlFileName> |
| | | <LongName> 2108100 - Disclosure - Deposits </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/Deposits </Role> |
| | | <ShortName> Deposits </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 18 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R19.htm </HtmlFileName> |
| | | <LongName> 2109100 - Disclosure - Net interest revenue </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/NetInterestRevenue </Role> |
| | | <ShortName> Net interest revenue </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 19 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R20.htm </HtmlFileName> |
| | | <LongName> 2110100 - Disclosure - Income taxes </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/IncomeTaxes </Role> |
| | | <ShortName> Income taxes </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 20 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R21.htm </HtmlFileName> |
| | | <LongName> 2111100 - Disclosure - Long-Term Debt </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LongTermDebt </Role> |
| | | <ShortName> Long-Term Debt </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 21 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R22.htm </HtmlFileName> |
| | | <LongName> 2112100 - Disclosure - Variable interest entities and securitization </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/VariableInterestEntitiesAndSecuritization </Role> |
| | | <ShortName> Variable interest entities and securitization </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 22 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R23.htm </HtmlFileName> |
| | | <LongName> 2113100 - Disclosure - Shareholders' equity </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ShareholdersEquity </Role> |
| | | <ShortName> Shareholders' equity </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 23 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R24.htm </HtmlFileName> |
| | | <LongName> 2114100 - Disclosure - Other comprehensive income (loss) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/OtherComprehensiveIncomeLoss </Role> |
| | | <ShortName> Other comprehensive income (loss) </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 24 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R25.htm </HtmlFileName> |
| | | <LongName> 2115100 - Disclosure - Stock-based compensation </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/StockBasedCompensation </Role> |
| | | <ShortName> Stock-based compensation </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 25 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R26.htm </HtmlFileName> |
| | | <LongName> 2116100 - Disclosure - Employee benefit plans </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlans </Role> |
| | | <ShortName> Employee benefit plans </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 26 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R27.htm </HtmlFileName> |
| | | <LongName> 2117100 - Disclosure - Company Financial Information (Parent Corporation) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporation </Role> |
| | | <ShortName> Company Financial Information (Parent Corporation) </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 27 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R28.htm </HtmlFileName> |
| | | <LongName> 2118100 - Disclosure - Fair value measurement </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueMeasurement </Role> |
| | | <ShortName> Fair value measurement </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 28 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R29.htm </HtmlFileName> |
| | | <LongName> 2119100 - Disclosure - Fair value option </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueOption </Role> |
| | | <ShortName> Fair value option </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 29 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R30.htm </HtmlFileName> |
| | | <LongName> 2120100 - Disclosure - Commitments and contingent liabilities </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CommitmentsAndContingentLiabilities </Role> |
| | | <ShortName> Commitments and contingent liabilities </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 30 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R31.htm </HtmlFileName> |
| | | <LongName> 2121100 - Disclosure - Derivative instruments </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstruments </Role> |
| | | <ShortName> Derivative instruments </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 31 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R32.htm </HtmlFileName> |
| | | <LongName> 2122100 - Disclosure - Lines of business </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LinesOfBusiness </Role> |
| | | <ShortName> Lines of business </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 32 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R33.htm </HtmlFileName> |
| | | <LongName> 2123100 - Disclosure - International Operations </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/InternationalOperations </Role> |
| | | <ShortName> International Operations </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 33 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R34.htm </HtmlFileName> |
| | | <LongName> 2124100 - Disclosure - Supplemental information to the Consolidated Statement of Cash Flows </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SupplementalInformationToConsolidatedStatementOfCashFlows </Role> |
| | | <ShortName> Supplemental information to the Consolidated Statement of Cash Flows </ShortName> |
| | | <MenuCategory> Notes </MenuCategory> |
| | | <Position> 34 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R35.htm </HtmlFileName> |
| | | <LongName> 2201201 - Disclosure - Summary of significant accounting and reporting policies (Policies) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SummaryOfSignificantAccountingAndReportingPoliciesPolicies </Role> |
| | | <ShortName> Summary of significant accounting and reporting policies (Policies) </ShortName> |
| | | <MenuCategory> Policies </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/AccountingChangeAndNewAccountingGuidance </ParentRole> |
| | | <Position> 35 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R36.htm </HtmlFileName> |
| | | <LongName> 2301302 - Disclosure - Summary of significant accounting and reporting policies (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SummaryOfSignificantAccountingAndReportingPoliciesTables </Role> |
| | | <ShortName> Summary of significant accounting and reporting policies (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/SummaryOfSignificantAccountingAndReportingPolicies </ParentRole> |
| | | <Position> 36 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R37.htm </HtmlFileName> |
| | | <LongName> 2304301 - Disclosure - Securities (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesTables </Role> |
| | | <ShortName> Securities (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/Securities </ParentRole> |
| | | <Position> 37 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R38.htm </HtmlFileName> |
| | | <LongName> 2305301 - Disclosure - Loans and asset quality (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityTables </Role> |
| | | <ShortName> Loans and asset quality (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/LoansAndAssetQuality </ParentRole> |
| | | <Position> 38 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R39.htm </HtmlFileName> |
| | | <LongName> 2306301 - Disclosure - Goodwill and intangible assets (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/GoodwillAndIntangibleAssetsTables </Role> |
| | | <ShortName> Goodwill and intangible assets (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/GoodwillAndIntangibleAssets </ParentRole> |
| | | <Position> 39 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R40.htm </HtmlFileName> |
| | | <LongName> 2307301 - Disclosure - Other assets (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/OtherAssetsTables </Role> |
| | | <ShortName> Other assets (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/OtherAssets </ParentRole> |
| | | <Position> 40 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R41.htm </HtmlFileName> |
| | | <LongName> 2309301 - Disclosure - Net interest revenue (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/NetInterestRevenueTables </Role> |
| | | <ShortName> Net interest revenue (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/NetInterestRevenue </ParentRole> |
| | | <Position> 41 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R42.htm </HtmlFileName> |
| | | <LongName> 2310301 - Disclosure - Income taxes (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/IncomeTaxesTables </Role> |
| | | <ShortName> Income taxes (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/IncomeTaxes </ParentRole> |
| | | <Position> 42 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R43.htm </HtmlFileName> |
| | | <LongName> 2311301 - Disclosure - Long-Term Debt (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LongTermDebtTables </Role> |
| | | <ShortName> Long-Term Debt (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/LongTermDebt </ParentRole> |
| | | <Position> 43 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R44.htm </HtmlFileName> |
| | | <LongName> 2312301 - Disclosure - Variable interest entities and securitization (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/VariableInterestEntitiesAndSecuritizationTables </Role> |
| | | <ShortName> Variable interest entities and securitization (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/VariableInterestEntitiesAndSecuritization </ParentRole> |
| | | <Position> 44 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R45.htm </HtmlFileName> |
| | | <LongName> 2313301 - Disclosure - Shareholders' equity (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ShareholdersEquityTables </Role> |
| | | <ShortName> Shareholders' equity (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/ShareholdersEquity </ParentRole> |
| | | <Position> 45 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R46.htm </HtmlFileName> |
| | | <LongName> 2314301 - Disclosure - Other comprehensive income (loss) (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/OtherComprehensiveIncomeLossTables </Role> |
| | | <ShortName> Other comprehensive income (loss) (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/OtherComprehensiveIncomeLoss </ParentRole> |
| | | <Position> 46 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R47.htm </HtmlFileName> |
| | | <LongName> 2315301 - Disclosure - Stock-based compensation (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/StockBasedCompensationTables </Role> |
| | | <ShortName> Stock-based compensation (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/StockBasedCompensation </ParentRole> |
| | | <Position> 47 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R48.htm </HtmlFileName> |
| | | <LongName> 2316301 - Disclosure - Employee benefit plans (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansTables </Role> |
| | | <ShortName> Employee benefit plans (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/EmployeeBenefitPlans </ParentRole> |
| | | <Position> 48 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R49.htm </HtmlFileName> |
| | | <LongName> 2317301 - Disclosure - Company Financial Information (Parent Corporation) (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporationTables </Role> |
| | | <ShortName> Company Financial Information (Parent Corporation) (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporation </ParentRole> |
| | | <Position> 49 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R50.htm </HtmlFileName> |
| | | <LongName> 2318301 - Disclosure - Fair value measurement (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueMeasurementTables </Role> |
| | | <ShortName> Fair value measurement (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/FairValueMeasurement </ParentRole> |
| | | <Position> 50 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R51.htm </HtmlFileName> |
| | | <LongName> 2319301 - Disclosure - Fair value option (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueOptionTables </Role> |
| | | <ShortName> Fair value option (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/FairValueOption </ParentRole> |
| | | <Position> 51 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R52.htm </HtmlFileName> |
| | | <LongName> 2320301 - Disclosure - Commitments and contingent liabilities (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CommitmentsAndContingentLiabilitiesTables </Role> |
| | | <ShortName> Commitments and contingent liabilities (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/CommitmentsAndContingentLiabilities </ParentRole> |
| | | <Position> 52 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R53.htm </HtmlFileName> |
| | | <LongName> 2321301 - Disclosure - Derivative instruments (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstrumentsTables </Role> |
| | | <ShortName> Derivative instruments (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/DerivativeInstruments </ParentRole> |
| | | <Position> 53 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R54.htm </HtmlFileName> |
| | | <LongName> 2322301 - Disclosure - Lines of business (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LinesOfBusinessTables </Role> |
| | | <ShortName> Lines of business (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/LinesOfBusiness </ParentRole> |
| | | <Position> 54 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R55.htm </HtmlFileName> |
| | | <LongName> 2323301 - Disclosure - International Operations (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/InternationalOperationsTables </Role> |
| | | <ShortName> International Operations (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/InternationalOperations </ParentRole> |
| | | <Position> 55 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R56.htm </HtmlFileName> |
| | | <LongName> 2324301 - Disclosure - Supplemental information to the Consolidated Statement of Cash Flows (Tables) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SupplementalInformationToConsolidatedStatementOfCashFlowsTables </Role> |
| | | <ShortName> Supplemental information to the Consolidated Statement of Cash Flows (Tables) </ShortName> |
| | | <MenuCategory> Tables </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/SupplementalInformationToConsolidatedStatementOfCashFlows </ParentRole> |
| | | <Position> 56 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R57.htm </HtmlFileName> |
| | | <LongName> 2401403 - Disclosure - Summary of significant accounting and reporting policies - Additional Information (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SummaryOfSignificantAccountingAndReportingPoliciesAdditionalInformationDetails </Role> |
| | | <ShortName> Summary of significant accounting and reporting policies - Additional Information (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 57 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R58.htm </HtmlFileName> |
| | | <LongName> 2401404 - Disclosure - Summary of significant accounting and reporting policies - Equity Method Investments (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SummaryOfSignificantAccountingAndReportingPoliciesEquityMethodInvestmentsDetails </Role> |
| | | <ShortName> Summary of significant accounting and reporting policies - Equity Method Investments (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 58 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R59.htm </HtmlFileName> |
| | | <LongName> 2402401 - Disclosure - Accounting change and new accounting guidance (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/AccountingChangeAndNewAccountingGuidanceDetails </Role> |
| | | <ShortName> Accounting change and new accounting guidance (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 59 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R60.htm </HtmlFileName> |
| | | <LongName> 2403401 - Disclosure - Acquisitions (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/AcquisitionsDetails </Role> |
| | | <ShortName> Acquisitions (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/Acquisitions </ParentRole> |
| | | <Position> 60 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R61.htm </HtmlFileName> |
| | | <LongName> 2404402 - Disclosure - Securities - Amortized Cost, Gross Unrealized Gains and Losses and Fair Value (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesAmortizedCostGrossUnrealizedGainsAndLossesAndFairValueDetail </Role> |
| | | <ShortName> Securities - Amortized Cost, Gross Unrealized Gains and Losses and Fair Value (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 61 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R62.htm </HtmlFileName> |
| | | <LongName> 2404403 - Disclosure - Securities - Net Securities Gains (Losses) (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesNetSecuritiesGainsLossesDetail </Role> |
| | | <ShortName> Securities - Net Securities Gains (Losses) (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 62 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R63.htm </HtmlFileName> |
| | | <LongName> 2404404 - Disclosure - Securities - Fair Value of Investments with Continuous Unrealized Loss Position (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesFairValueOfInvestmentsWithContinuousUnrealizedLossPositionDetail </Role> |
| | | <ShortName> Securities - Fair Value of Investments with Continuous Unrealized Loss Position (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 63 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R64.htm </HtmlFileName> |
| | | <LongName> 2404405 - Disclosure - Securities - Maturity Distribution and Yield of Investment Securities Portfolio (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesMaturityDistributionAndYieldOfInvestmentSecuritiesPortfolioDetail </Role> |
| | | <ShortName> Securities - Maturity Distribution and Yield of Investment Securities Portfolio (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 64 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R65.htm </HtmlFileName> |
| | | <LongName> 2404406 - Disclosure - Securities - Projected Weighted-Average Default Rates and Loss Severities (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesProjectedWeightedAverageDefaultRatesAndLossSeveritiesDetail </Role> |
| | | <ShortName> Securities - Projected Weighted-Average Default Rates and Loss Severities (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 65 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R66.htm </HtmlFileName> |
| | | <LongName> 2404407 - Disclosure - Securities - Pre-Tax Net Securities Gains (Losses) by Type (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesPreTaxNetSecuritiesGainsLossesByTypeDetail </Role> |
| | | <ShortName> Securities - Pre-Tax Net Securities Gains (Losses) by Type (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 66 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R67.htm </HtmlFileName> |
| | | <LongName> 2404408 - Disclosure - Securities - Debt Securities Credit Losses Roll Forward Recorded in Earnings (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesDebtSecuritiesCreditLossesRollForwardRecordedInEarningsDetail </Role> |
| | | <ShortName> Securities - Debt Securities Credit Losses Roll Forward Recorded in Earnings (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 67 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R68.htm </HtmlFileName> |
| | | <LongName> 2404409 - Disclosure - Securities - Pledged assets (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesPledgedAssetsDetails </Role> |
| | | <ShortName> Securities - Pledged assets (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 68 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R69.htm </HtmlFileName> |
| | | <LongName> 2404410 - Disclosure - Securities - Narrative (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SecuritiesNarrativeDetails </Role> |
| | | <ShortName> Securities - Narrative (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 69 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R70.htm </HtmlFileName> |
| | | <LongName> 2405402 - Disclosure - Loans and asset quality - Loan Distribution and Industry Concentrations (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityLoanDistributionAndIndustryConcentrationsDetail </Role> |
| | | <ShortName> Loans and asset quality - Loan Distribution and Industry Concentrations (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 70 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R71.htm </HtmlFileName> |
| | | <LongName> 2405403 - Disclosure - Loans and asset quality - Allowance for Credit Losses Activity (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityAllowanceForCreditLossesActivityDetails </Role> |
| | | <ShortName> Loans and asset quality - Allowance for Credit Losses Activity (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 71 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R72.htm </HtmlFileName> |
| | | <LongName> 2405404 - Disclosure - Loans and asset quality - Nonperforming Assets (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityNonperformingAssetsDetail </Role> |
| | | <ShortName> Loans and asset quality - Nonperforming Assets (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 72 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R73.htm </HtmlFileName> |
| | | <LongName> 2405405 - Disclosure - Loans and asset quality - Lost Interest (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityLostInterestDetail </Role> |
| | | <ShortName> Loans and asset quality - Lost Interest (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 73 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R74.htm </HtmlFileName> |
| | | <LongName> 2405406 - Disclosure - Loans and asset quality - Information about Impaired Loans (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityInformationAboutImpairedLoansDetail </Role> |
| | | <ShortName> Loans and asset quality - Information about Impaired Loans (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 74 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R75.htm </HtmlFileName> |
| | | <LongName> 2405407 - Disclosure - Loans and asset quality - Information about Past Due Loans (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityInformationAboutPastDueLoansDetail </Role> |
| | | <ShortName> Loans and asset quality - Information about Past Due Loans (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 75 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R76.htm </HtmlFileName> |
| | | <LongName> 2405408 - Disclosure - Loans and asset quality - Troubled Debt Restructurings (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityTroubledDebtRestructuringsDetail </Role> |
| | | <ShortName> Loans and asset quality - Troubled Debt Restructurings (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 76 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R77.htm </HtmlFileName> |
| | | <LongName> 2405409 - Disclosure - Loans and asset quality - Credit Risk Profile by Grade (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityCreditRiskProfileByGradeDetail </Role> |
| | | <ShortName> Loans and asset quality - Credit Risk Profile by Grade (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 77 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R78.htm </HtmlFileName> |
| | | <LongName> 2405410 - Disclosure - Loans and asset quality - Additional Information (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LoansAndAssetQualityAdditionalInformationDetails </Role> |
| | | <ShortName> Loans and asset quality - Additional Information (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 78 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R79.htm </HtmlFileName> |
| | | <LongName> 2406402 - Disclosure - Goodwill and intangible assets - Goodwill (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/GoodwillAndIntangibleAssetsGoodwillDetail </Role> |
| | | <ShortName> Goodwill and intangible assets - Goodwill (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 79 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R80.htm </HtmlFileName> |
| | | <LongName> 2406403 - Disclosure - Goodwill and intangible assets - Intangible Assets by Business Segment (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/GoodwillAndIntangibleAssetsIntangibleAssetsByBusinessSegmentDetail </Role> |
| | | <ShortName> Goodwill and intangible assets - Intangible Assets by Business Segment (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 80 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R81.htm </HtmlFileName> |
| | | <LongName> 2406404 - Disclosure - Goodwill and intangible assets - Intangible Assets by Type (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/GoodwillAndIntangibleAssetsIntangibleAssetsByTypeDetail </Role> |
| | | <ShortName> Goodwill and intangible assets - Intangible Assets by Type (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 81 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R82.htm </HtmlFileName> |
| | | <LongName> 2406405 - Disclosure - Goodwill and intangible assets - Estimated Annual Amortization Expense (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/GoodwillAndIntangibleAssetsEstimatedAnnualAmortizationExpenseDetail </Role> |
| | | <ShortName> Goodwill and intangible assets - Estimated Annual Amortization Expense (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 82 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R83.htm </HtmlFileName> |
| | | <LongName> 2407402 - Disclosure - Other assets - Components of Other Assets (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/OtherAssetsComponentsOfOtherAssetsDetail </Role> |
| | | <ShortName> Other assets - Components of Other Assets (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 83 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R84.htm </HtmlFileName> |
| | | <LongName> 2407403 - Disclosure - Other assets - Qualified Affordable Housing Project Investments (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/OtherAssetsQualifiedAffordableHousingProjectInvestmentsDetails </Role> |
| | | <ShortName> Other assets - Qualified Affordable Housing Project Investments (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 84 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R85.htm </HtmlFileName> |
| | | <LongName> 2407404 - Disclosure - Other assets - Seed Capital and Private Equity Investments (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/OtherAssetsSeedCapitalAndPrivateEquityInvestmentsDetail </Role> |
| | | <ShortName> Other assets - Seed Capital and Private Equity Investments (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 85 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R86.htm </HtmlFileName> |
| | | <LongName> 2408401 - Disclosure - Deposits (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DepositsDetail </Role> |
| | | <ShortName> Deposits (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/Deposits </ParentRole> |
| | | <Position> 86 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R87.htm </HtmlFileName> |
| | | <LongName> 2409402 - Disclosure - Net interest revenue (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/NetInterestRevenueDetails </Role> |
| | | <ShortName> Net interest revenue (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/NetInterestRevenueTables </ParentRole> |
| | | <Position> 87 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R88.htm </HtmlFileName> |
| | | <LongName> 2410402 - Disclosure - Income taxes - Narrative (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/IncomeTaxesNarrativeDetail </Role> |
| | | <ShortName> Income taxes - Narrative (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 88 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R89.htm </HtmlFileName> |
| | | <LongName> 2410403 - Disclosure - Income taxes - Provision (Benefit) for Income Taxes from Continuing Operations (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/IncomeTaxesProvisionBenefitForIncomeTaxesFromContinuingOperationsDetail </Role> |
| | | <ShortName> Income taxes - Provision (Benefit) for Income Taxes from Continuing Operations (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 89 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R90.htm </HtmlFileName> |
| | | <LongName> 2410404 - Disclosure - Income taxes Income taxes - Provisional Tax Expense (Benefit) (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/IncomeTaxesIncomeTaxesProvisionalTaxExpenseBenefitDetails </Role> |
| | | <ShortName> Income taxes Income taxes - Provisional Tax Expense (Benefit) (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 90 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R91.htm </HtmlFileName> |
| | | <LongName> 2410405 - Disclosure - Income taxes - Components of Income (Loss) before Taxes (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/IncomeTaxesComponentsOfIncomeLossBeforeTaxesDetail </Role> |
| | | <ShortName> Income taxes - Components of Income (Loss) before Taxes (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 91 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R92.htm </HtmlFileName> |
| | | <LongName> 2410406 - Disclosure - Income taxes - Components of Net Deferred Tax Liability (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/IncomeTaxesComponentsOfNetDeferredTaxLiabilityDetail </Role> |
| | | <ShortName> Income taxes - Components of Net Deferred Tax Liability (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 92 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R93.htm </HtmlFileName> |
| | | <LongName> 2410407 - Disclosure - Income taxes Income taxes - Reconciliation of Effective Tax Rate (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/IncomeTaxesIncomeTaxesReconciliationOfEffectiveTaxRateDetail </Role> |
| | | <ShortName> Income taxes Income taxes - Reconciliation of Effective Tax Rate (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 93 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R94.htm </HtmlFileName> |
| | | <LongName> 2410408 - Disclosure - Income taxes - Unrecognized Tax Positions (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/IncomeTaxesUnrecognizedTaxPositionsDetail </Role> |
| | | <ShortName> Income taxes - Unrecognized Tax Positions (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 94 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R95.htm </HtmlFileName> |
| | | <LongName> 2411402 - Disclosure - Long-Term Debt - Schedule of Long-term Debt (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LongTermDebtScheduleOfLongTermDebtDetail </Role> |
| | | <ShortName> Long-Term Debt - Schedule of Long-term Debt (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 95 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R96.htm </HtmlFileName> |
| | | <LongName> 2411403 - Disclosure - Long-Term Debt - Additional Information (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LongTermDebtAdditionalInformationDetail </Role> |
| | | <ShortName> Long-Term Debt - Additional Information (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 96 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R97.htm </HtmlFileName> |
| | | <LongName> 2412402 - Disclosure - Variable interest entities and securitization - Assets and Liabilities of VIEs (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/VariableInterestEntitiesAndSecuritizationAssetsAndLiabilitiesOfViesDetail </Role> |
| | | <ShortName> Variable interest entities and securitization - Assets and Liabilities of VIEs (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 97 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R98.htm </HtmlFileName> |
| | | <LongName> 2412403 - Disclosure - Variable interest entities and securitization - Non-consolidated VIEs (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/VariableInterestEntitiesAndSecuritizationNonConsolidatedViesDetail </Role> |
| | | <ShortName> Variable interest entities and securitization - Non-consolidated VIEs (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 98 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R99.htm </HtmlFileName> |
| | | <LongName> 2413402 - Disclosure - Shareholders' equity - Narrative (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ShareholdersEquityNarrativeDetails </Role> |
| | | <ShortName> Shareholders' equity - Narrative (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 99 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R100.htm </HtmlFileName> |
| | | <LongName> 2413403 - Disclosure - Shareholders' equity - Preferred Stock Summary (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ShareholdersEquityPreferredStockSummaryDetails </Role> |
| | | <ShortName> Shareholders' equity - Preferred Stock Summary (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 100 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R101.htm </HtmlFileName> |
| | | <LongName> 2413404 - Disclosure - Shareholders' equity - Capital adequacy (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/ShareholdersEquityCapitalAdequacyDetails </Role> |
| | | <ShortName> Shareholders' equity - Capital adequacy (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 101 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R102.htm </HtmlFileName> |
| | | <LongName> 2414402 - Disclosure - Other comprehensive income (loss) - Components (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/OtherComprehensiveIncomeLossComponentsDetails </Role> |
| | | <ShortName> Other comprehensive income (loss) - Components (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/OtherComprehensiveIncomeLossTables </ParentRole> |
| | | <Position> 102 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R103.htm </HtmlFileName> |
| | | <LongName> 2414403 - Disclosure - Other comprehensive income (loss) - Changes in AOCI (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/OtherComprehensiveIncomeLossChangesInAociDetails </Role> |
| | | <ShortName> Other comprehensive income (loss) - Changes in AOCI (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/OtherComprehensiveIncomeLossTables </ParentRole> |
| | | <Position> 103 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R104.htm </HtmlFileName> |
| | | <LongName> 2415402 - Disclosure - Stock-based compensation - Additional Information (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/StockBasedCompensationAdditionalInformationDetail </Role> |
| | | <ShortName> Stock-based compensation - Additional Information (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 104 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R105.htm </HtmlFileName> |
| | | <LongName> 2415403 - Disclosure - Stock-based compensation - Summary of Stock Option Activity (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/StockBasedCompensationSummaryOfStockOptionActivityDetail </Role> |
| | | <ShortName> Stock-based compensation - Summary of Stock Option Activity (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 105 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R106.htm </HtmlFileName> |
| | | <LongName> 2415404 - Disclosure - Stock-based compensation - Stock Options Outstanding (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/StockBasedCompensationStockOptionsOutstandingDetail </Role> |
| | | <ShortName> Stock-based compensation - Stock Options Outstanding (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 106 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R107.htm </HtmlFileName> |
| | | <LongName> 2415405 - Disclosure - Stock-based compensation - Aggregate Intrinsic Value of Options (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/StockBasedCompensationAggregateIntrinsicValueOfOptionsDetail </Role> |
| | | <ShortName> Stock-based compensation - Aggregate Intrinsic Value of Options (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 107 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R108.htm </HtmlFileName> |
| | | <LongName> 2415406 - Disclosure - Stock-based compensation - Nonvested Restricted Stock and Restricted Stock Units Activity (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/StockBasedCompensationNonvestedRestrictedStockAndRestrictedStockUnitsActivityDetail </Role> |
| | | <ShortName> Stock-based compensation - Nonvested Restricted Stock and Restricted Stock Units Activity (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 108 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R109.htm </HtmlFileName> |
| | | <LongName> 2416402 - Disclosure - Employee Benefit Plans - Combined Data for Defined Benefit Pension and Post Retirement Healthcare Plans (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansCombinedDataForDefinedBenefitPensionAndPostRetirementHealthcarePlansDetail </Role> |
| | | <ShortName> Employee Benefit Plans - Combined Data for Defined Benefit Pension and Post Retirement Healthcare Plans (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 109 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R110.htm </HtmlFileName> |
| | | <LongName> 2416403 - Disclosure - Employee Benefit Plans - Net Periodic Benefit (Credit) Cost (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansNetPeriodicBenefitCreditCostDetails </Role> |
| | | <ShortName> Employee Benefit Plans - Net Periodic Benefit (Credit) Cost (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 110 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R111.htm </HtmlFileName> |
| | | <LongName> 2416404 - Disclosure - Employee Benefit Plans - Changes in Other Comprehensive Income (Loss) (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansChangesInOtherComprehensiveIncomeLossDetails </Role> |
| | | <ShortName> Employee Benefit Plans - Changes in Other Comprehensive Income (Loss) (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 111 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R112.htm </HtmlFileName> |
| | | <LongName> 2416405 - Disclosure - Employee Benefit Plans - Amounts Expected to be Recognized in Net Periodic Benefit Income (Cost) (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansAmountsExpectedToBeRecognizedInNetPeriodicBenefitIncomeCostDetails </Role> |
| | | <ShortName> Employee Benefit Plans - Amounts Expected to be Recognized in Net Periodic Benefit Income (Cost) (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 112 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R113.htm </HtmlFileName> |
| | | <LongName> 2416406 - Disclosure - Employee Benefit Plans - Defined Benefit Plan Funded Status of Plan (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansDefinedBenefitPlanFundedStatusOfPlanDetails </Role> |
| | | <ShortName> Employee Benefit Plans - Defined Benefit Plan Funded Status of Plan (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 113 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R114.htm </HtmlFileName> |
| | | <LongName> 2416407 - Disclosure - Employee Benefit Plans - Plans with Obligations in Excess of Plan Assets (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansPlansWithObligationsInExcessOfPlanAssetsDetails </Role> |
| | | <ShortName> Employee Benefit Plans - Plans with Obligations in Excess of Plan Assets (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 114 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R115.htm </HtmlFileName> |
| | | <LongName> 2416408 - Disclosure - Employee Benefit Plans - Benefit Payments and Expected to be Paid (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansBenefitPaymentsAndExpectedToBePaidDetails </Role> |
| | | <ShortName> Employee Benefit Plans - Benefit Payments and Expected to be Paid (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 115 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R116.htm </HtmlFileName> |
| | | <LongName> 2416409 - Disclosure - Employee Benefit Plans - Pension Investment Asset Allocation (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansPensionInvestmentAssetAllocationDetail </Role> |
| | | <ShortName> Employee Benefit Plans - Pension Investment Asset Allocation (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 116 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R117.htm </HtmlFileName> |
| | | <LongName> 2416410 - Disclosure - Employee Benefit Plans - Pension Plan Investment Assets on Recurring Basis (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansPensionPlanInvestmentAssetsOnRecurringBasisDetail </Role> |
| | | <ShortName> Employee Benefit Plans - Pension Plan Investment Assets on Recurring Basis (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 117 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R118.htm </HtmlFileName> |
| | | <LongName> 2416411 - Disclosure - Employee Benefit Plans - Rollforward of Plan Investment Assets (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansRollforwardOfPlanInvestmentAssetsDetail </Role> |
| | | <ShortName> Employee Benefit Plans - Rollforward of Plan Investment Assets (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 118 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R119.htm </HtmlFileName> |
| | | <LongName> 2416412 - Disclosure - Employee Benefit Plans - Pension Plan Assets Valued Using Net Asset Value (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansPensionPlanAssetsValuedUsingNetAssetValueDetail </Role> |
| | | <ShortName> Employee Benefit Plans - Pension Plan Assets Valued Using Net Asset Value (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 119 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R120.htm </HtmlFileName> |
| | | <LongName> 2416413 - Disclosure - Employee Benefit Plans - Additional Information (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/EmployeeBenefitPlansAdditionalInformationDetail </Role> |
| | | <ShortName> Employee Benefit Plans - Additional Information (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 120 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R121.htm </HtmlFileName> |
| | | <LongName> 2417402 - Disclosure - Company Financial Information (Parent Corporation) - Income Statement (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporationIncomeStatementDetails </Role> |
| | | <ShortName> Company Financial Information (Parent Corporation) - Income Statement (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporationTables </ParentRole> |
| | | <Position> 121 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R122.htm </HtmlFileName> |
| | | <LongName> 2417403 - Disclosure - Company Financial Information (Parent Corporation) - Balance Sheet (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporationBalanceSheetDetails </Role> |
| | | <ShortName> Company Financial Information (Parent Corporation) - Balance Sheet (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporationTables </ParentRole> |
| | | <Position> 122 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R123.htm </HtmlFileName> |
| | | <LongName> 2417404 - Disclosure - Company Financial Information (Parent Corporation) - Cash Flows (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporationCashFlowsDetails </Role> |
| | | <ShortName> Company Financial Information (Parent Corporation) - Cash Flows (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporationTables </ParentRole> |
| | | <Position> 123 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R124.htm </HtmlFileName> |
| | | <LongName> 2417405 - Disclosure - Company Financial Information (Parent Corporation) - Additional Information (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporationAdditionalInformationDetails </Role> |
| | | <ShortName> Company Financial Information (Parent Corporation) - Additional Information (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/CompanyFinancialInformationParentCorporationTables </ParentRole> |
| | | <Position> 124 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R125.htm </HtmlFileName> |
| | | <LongName> 2418402 - Disclosure - Fair value measurement - Narrative (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueMeasurementNarrativeDetails </Role> |
| | | <ShortName> Fair value measurement - Narrative (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 125 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R126.htm </HtmlFileName> |
| | | <LongName> 2418403 - Disclosure - Fair value measurement - Assets and Liabilities on Recurring Basis (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueMeasurementAssetsAndLiabilitiesOnRecurringBasisDetails </Role> |
| | | <ShortName> Fair value measurement - Assets and Liabilities on Recurring Basis (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 126 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R127.htm </HtmlFileName> |
| | | <LongName> 2418404 - Disclosure - Fair value measurement - Certain Items on Recurring Basis (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueMeasurementCertainItemsOnRecurringBasisDetails </Role> |
| | | <ShortName> Fair value measurement - Certain Items on Recurring Basis (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 127 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R128.htm </HtmlFileName> |
| | | <LongName> 2418405 - Disclosure - Fair value measurement - Assets Using Significant Unobservable Inputs (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueMeasurementAssetsUsingSignificantUnobservableInputsDetails </Role> |
| | | <ShortName> Fair value measurement - Assets Using Significant Unobservable Inputs (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 128 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R129.htm </HtmlFileName> |
| | | <LongName> 2418406 - Disclosure - Fair value measurement - Assets on Nonrecurring Basis (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueMeasurementAssetsOnNonrecurringBasisDetails </Role> |
| | | <ShortName> Fair value measurement - Assets on Nonrecurring Basis (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 129 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R130.htm </HtmlFileName> |
| | | <LongName> 2418407 - Disclosure - Fair value measurement - Financial Instruments (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueMeasurementFinancialInstrumentsDetails </Role> |
| | | <ShortName> Fair value measurement - Financial Instruments (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 130 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R131.htm </HtmlFileName> |
| | | <LongName> 2418408 - Disclosure - Fair value measurement - Derivatives (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueMeasurementDerivativesDetails </Role> |
| | | <ShortName> Fair value measurement - Derivatives (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 131 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R132.htm </HtmlFileName> |
| | | <LongName> 2419402 - Disclosure - Fair value option - Assets and Liabilities (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueOptionAssetsAndLiabilitiesDetail </Role> |
| | | <ShortName> Fair value option - Assets and Liabilities (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 132 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R133.htm </HtmlFileName> |
| | | <LongName> 2419403 - Disclosure - Fair value option - Changes in Fair Value of Loans (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueOptionChangesInFairValueOfLoansDetails </Role> |
| | | <ShortName> Fair value option - Changes in Fair Value of Loans (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 133 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R134.htm </HtmlFileName> |
| | | <LongName> 2419404 - Disclosure - Fair value option - Narrative (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/FairValueOptionNarrativeDetails </Role> |
| | | <ShortName> Fair value option - Narrative (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 134 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R135.htm </HtmlFileName> |
| | | <LongName> 2420402 - Disclosure - Commitments and contingent liabilities - Summary of Off-Balance Sheet Credit Risks, Net of Participations (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CommitmentsAndContingentLiabilitiesSummaryOfOffBalanceSheetCreditRisksNetOfParticipationsDetails </Role> |
| | | <ShortName> Commitments and contingent liabilities - Summary of Off-Balance Sheet Credit Risks, Net of Participations (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 135 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R136.htm </HtmlFileName> |
| | | <LongName> 2420403 - Disclosure - Commitments and contingent liabilities - Standby Letters of Credits by Investment Grade (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CommitmentsAndContingentLiabilitiesStandbyLettersOfCreditsByInvestmentGradeDetails </Role> |
| | | <ShortName> Commitments and contingent liabilities - Standby Letters of Credits by Investment Grade (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 136 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R137.htm </HtmlFileName> |
| | | <LongName> 2420404 - Disclosure - Commitments and contingent liabilities - Significant Industry Concentrations Related to Credit Exposure (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CommitmentsAndContingentLiabilitiesSignificantIndustryConcentrationsRelatedToCreditExposureDetails </Role> |
| | | <ShortName> Commitments and contingent liabilities - Significant Industry Concentrations Related to Credit Exposure (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 137 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R138.htm </HtmlFileName> |
| | | <LongName> 2420405 - Disclosure - Commitments and contingent liabilities - Narrative (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/CommitmentsAndContingentLiabilitiesNarrativeDetails </Role> |
| | | <ShortName> Commitments and contingent liabilities - Narrative (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 138 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R139.htm </HtmlFileName> |
| | | <LongName> 2421402 - Disclosure - Derivative instruments - Narrative (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstrumentsNarrativeDetails </Role> |
| | | <ShortName> Derivative instruments - Narrative (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 139 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R140.htm </HtmlFileName> |
| | | <LongName> 2421403 - Disclosure - Derivative instruments - Ineffectiveness Recorded in Income (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstrumentsIneffectivenessRecordedInIncomeDetails </Role> |
| | | <ShortName> Derivative instruments - Ineffectiveness Recorded in Income (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 140 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R141.htm </HtmlFileName> |
| | | <LongName> 2421404 - Disclosure - Derivative instruments - Impact of Derivative Instruments on the Balance Sheet (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstrumentsImpactOfDerivativeInstrumentsOnBalanceSheetDetails </Role> |
| | | <ShortName> Derivative instruments - Impact of Derivative Instruments on the Balance Sheet (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 141 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R142.htm </HtmlFileName> |
| | | <LongName> 2421405 - Disclosure - Derivative instruments - Impact of Derivative Instruments in the Income Statement (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstrumentsImpactOfDerivativeInstrumentsInIncomeStatementDetails </Role> |
| | | <ShortName> Derivative instruments - Impact of Derivative Instruments in the Income Statement (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 142 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R143.htm </HtmlFileName> |
| | | <LongName> 2421406 - Disclosure - Derivative instruments - Revenue from Foreign Exchange and Other Trading (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstrumentsRevenueFromForeignExchangeAndOtherTradingDetails </Role> |
| | | <ShortName> Derivative instruments - Revenue from Foreign Exchange and Other Trading (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 143 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R144.htm </HtmlFileName> |
| | | <LongName> 2421407 - Disclosure - Derivative instruments - Contracts Falling under Early Termination Provisions (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstrumentsContractsFallingUnderEarlyTerminationProvisionsDetails </Role> |
| | | <ShortName> Derivative instruments - Contracts Falling under Early Termination Provisions (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 144 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R145.htm </HtmlFileName> |
| | | <LongName> 2421408 - Disclosure - Derivative instruments - Offsetting (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstrumentsOffsettingDetails </Role> |
| | | <ShortName> Derivative instruments - Offsetting (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 145 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R146.htm </HtmlFileName> |
| | | <LongName> 2421409 - Disclosure - Derivative instruments - Secured Borrowings (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/DerivativeInstrumentsSecuredBorrowingsDetails </Role> |
| | | <ShortName> Derivative instruments - Secured Borrowings (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 146 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R147.htm </HtmlFileName> |
| | | <LongName> 2422402 - Disclosure - Lines of business - Narrative (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LinesOfBusinessNarrativeDetails </Role> |
| | | <ShortName> Lines of business - Narrative (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 147 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R148.htm </HtmlFileName> |
| | | <LongName> 2422403 - Disclosure - Lines of business - Contribution of Segments to Overall Profitability (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/LinesOfBusinessContributionOfSegmentsToOverallProfitabilityDetails </Role> |
| | | <ShortName> Lines of business - Contribution of Segments to Overall Profitability (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <Position> 148 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R149.htm </HtmlFileName> |
| | | <LongName> 2423402 - Disclosure - International Operations (Details) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/InternationalOperationsDetails </Role> |
| | | <ShortName> International Operations (Details) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/InternationalOperationsTables </ParentRole> |
| | | <Position> 149 </Position> |
| | | </Report> |
| | <Report instance="bk-20171231.xml"> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <HtmlFileName> R150.htm </HtmlFileName> |
| | | <LongName> 2424402 - Disclosure - Supplemental information to the Consolidated Statement of Cash Flows (Detail) </LongName> |
| | | <ReportType> Sheet </ReportType> |
| | | <Role> http://www.bnymellon.com/role/SupplementalInformationToConsolidatedStatementOfCashFlowsDetail </Role> |
| | | <ShortName> Supplemental information to the Consolidated Statement of Cash Flows (Detail) </ShortName> |
| | | <MenuCategory> Details </MenuCategory> |
| | | <ParentRole> http://www.bnymellon.com/role/SupplementalInformationToConsolidatedStatementOfCashFlowsTables </ParentRole> |
| | | <Position> 150 </Position> |
| | | </Report> |
| | <Report> |
| | | <IsDefault> false </IsDefault> |
| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <LongName> All Reports </LongName> |
| | | <ReportType> Book </ReportType> |
| | | <ShortName> All Reports </ShortName> |
| | | </Report> |
| | </MyReports> |
| <InputFiles> |
| | <File> bk-20171231.xml </File> |
| | <File> bk-20171231.xsd </File> |
| | <File> bk-20171231_cal.xml </File> |
| | <File> bk-20171231_def.xml </File> |
| | <File> bk-20171231_lab.xml </File> |
| | <File> bk-20171231_pre.xml </File> |
| | </InputFiles> |
| <SupplementalFiles/> |
| <BaseTaxonomies> |
| | <BaseTaxonomy> http://fasb.org/us-gaap/2017-01-31 </BaseTaxonomy> |
| | <BaseTaxonomy> http://xbrl.sec.gov/dei/2014-01-31 </BaseTaxonomy> |
| | <BaseTaxonomy> http://xbrl.sec.gov/invest/2013-01-31 </BaseTaxonomy> |
| | <BaseTaxonomy> http://xbrl.sec.gov/country/2017-01-31 </BaseTaxonomy> |
| | <BaseTaxonomy> http://xbrl.sec.gov/stpr/2011-01-31 </BaseTaxonomy> |
| | </BaseTaxonomies> |
| <HasPresentationLinkbase> true </HasPresentationLinkbase> |
| <HasCalculationLinkbase> true </HasCalculationLinkbase> |
| </FilingSummary> |