1.0.0.3 false Statement Of Financial Position Unclassified - Deposit Based Operations (USD $) In Millions false 1 $ false false iso4217_USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 iso4217_USD_per_shares Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 shares Standard http://www.xbrl.org/2003/instance shares 0 false 2 $ false false iso4217_USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 iso4217_USD_per_shares Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 shares Standard http://www.xbrl.org/2003/instance shares 0 5 3 us-gaap_AssetsAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 6 4 us-gaap_CashAndDueFromBanks us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 true true 6988000000 6988 false false 2 true true 13354000000 13354 false false No definition available. No authoritative reference available. false 7 4 us-gaap_InterestBearingDepositsInBanks us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 25003000000 25003 false false 2 false true 65316000000 65316 false false No definition available. No authoritative reference available. false 8 4 us-gaap_CashAndSecuritiesSegregatedUnderFederalAndOtherRegulations us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 23712000000 23712 false false 2 false true 24039000000 24039 false false No definition available. No authoritative reference available. false 9 4 us-gaap_FinancialInstrumentsOwnedAtFairValueAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 10 5 us-gaap_FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 62215000000 62215 false false 2 false true 28012000000 28012 false false No definition available. No authoritative reference available. false 11 5 us-gaap_FinancialInstrumentsOwnedOtherSovereignGovernmentObligationsAtFairValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 25445000000 25445 false false 2 false true 21084000000 21084 false false No definition available. No authoritative reference available. false 12 5 us-gaap_FinancialInstrumentsOwnedCorporateDebtAtFairValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 90454000000 90454 false false 2 false true 87294000000 87294 false false No definition available. No authoritative reference available. false 13 5 us-gaap_FinancialInstrumentsOwnedCorporateEquitiesAtFairValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 57968000000 57968 false false 2 false true 42321000000 42321 false false No definition available. No authoritative reference available. false 14 5 us-gaap_FinancialInstrumentsOwnedDerivativesAndOtherContractualAgreementsAtFairValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 49081000000 49081 false false 2 false true 89418000000 89418 false false No definition available. No authoritative reference available. false 15 5 us-gaap_FinancialInstrumentsOwnedPrincipalInvestmentsAtFairValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 9286000000 9286 false false 2 false true 10385000000 10385 false false No definition available. No authoritative reference available. false 16 5 us-gaap_FinancialInstrumentsOwnedPhysicalCommoditiesAtFairValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 5329000000 5329 false false 2 false true 2126000000 2126 false false No definition available. No authoritative reference available. false 17 5 us-gaap_FinancialInstrumentsOwnedAtFairValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 299778000000 299778 false false 2 false true 280640000000 280640 false false No definition available. No authoritative reference available. true 18 4 us-gaap_SecuritiesReceivedAsCollateral us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 13656000000 13656 false false 2 false true 5231000000 5231 false false No definition available. No authoritative reference available. false 19 4 us-gaap_FederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 143208000000 143208 false false 2 false true 122709000000 122709 false false No definition available. No authoritative reference available. false 20 4 us-gaap_SecuritiesBorrowed us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 167501000000 167501 false false 2 false true 88052000000 88052 false false No definition available. No authoritative reference available. false 21 4 ms_ReceivablesNetAbstract ms false na duration string Receivables, Net [Abstract] false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false Receivables, Net [Abstract] false 22 5 us-gaap_AccountsReceivableNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 27594000000 27594 false false 2 false true 29265000000 29265 false false No definition available. No authoritative reference available. false 23 5 us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 5719000000 5719 false false 2 false true 6250000000 6250 false false No definition available. No authoritative reference available. false 24 5 us-gaap_LoansAndLeasesReceivableOther us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 7259000000 7259 false false 2 false true 6547000000 6547 false false No definition available. No authoritative reference available. false 25 5 us-gaap_AccruedFeesAndOtherRevenueReceivable us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 11164000000 11164 false false 2 false true 7258000000 7258 false false No definition available. No authoritative reference available. false 26 4 us-gaap_OtherInvestmentsAndSecuritiesAtCost us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 3752000000 3752 false false 2 false true 3709000000 3709 false false No definition available. No authoritative reference available. false 27 4 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 7067000000 7067 false false 2 false true 5095000000 5095 false false No definition available. No authoritative reference available. false 28 4 us-gaap_Goodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 7162000000 7162 false false 2 false true 2256000000 2256 false false No definition available. No authoritative reference available. false 29 4 us-gaap_IntangibleAssetsNetExcludingGoodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 5054000000 5054 false false 2 false true 906000000 906 false false No definition available. No authoritative reference available. false 30 4 us-gaap_OtherAssets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 16845000000 16845 false false 2 false true 16137000000 16137 false false No definition available. No authoritative reference available. false 31 4 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 771462000000 771462 false false 2 false true 676764000000 676764 false false No definition available. No authoritative reference available. true 32 3 us-gaap_LiabilitiesAndStockholdersEquityAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 33 4 us-gaap_ShortTermBorrowings us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2378000000 2378 false false 2 false true 10102000000 10102 false false No definition available. No authoritative reference available. false 34 4 us-gaap_Deposits us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 62215000000 62215 false false 2 false true 51355000000 51355 false false No definition available. No authoritative reference available. false 35 4 us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValueAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 36 5 us-gaap_FinancialInstrumentsSoldNotYetPurchasedUSGovernmentAndAgencyObligations us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 20503000000 20503 false false 2 false true 11902000000 11902 false false No definition available. No authoritative reference available. false 37 5 us-gaap_FinancialInstrumentsSoldNotYetPurchasedOtherSovereignGovernmentDebt us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 18244000000 18244 false false 2 false true 9511000000 9511 false false No definition available. No authoritative reference available. false 38 5 us-gaap_FinancialInstrumentsSoldNotYetPurchasedCorporateDebt us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 7826000000 7826 false false 2 false true 9927000000 9927 false false No definition available. No authoritative reference available. false 39 5 us-gaap_FinancialInstrumentsSoldNotYetPurchasedCorporateEquities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 22601000000 22601 false false 2 false true 16840000000 16840 false false No definition available. No authoritative reference available. false 40 5 ms_FinancialInstrumentsSoldNotYetPurchasedDerivativesAndOtherContracts ms false credit instant monetary Fair value as of the balance sheet date of obligations incurred arising from derivative and other contracts. false false false false false false false false false 1 false true 38209000000 38209 false false 2 false true 68554000000 68554 false false Fair value as of the balance sheet date of obligations incurred arising from derivative and other contracts. No authoritative reference available. false 41 5 us-gaap_FinancialInstrumentsSoldNotYetPurchasedPhysicalCommoditiesSold us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 33000000 33 false false No definition available. No authoritative reference available. false 42 5 us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 107383000000 107383 false false 2 false true 116767000000 116767 false false No definition available. No authoritative reference available. true 43 4 us-gaap_ObligationToReturnSecuritiesReceivedAsCollateral us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 13656000000 13656 false false 2 false true 5231000000 5231 false false No definition available. No authoritative reference available. false 44 4 us-gaap_SecuritiesSoldUnderAgreementsToRepurchase us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 159401000000 159401 false false 2 false true 92213000000 92213 false false No definition available. No authoritative reference available. false 45 4 us-gaap_SecuritiesLoaned us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 26246000000 26246 false false 2 false true 14580000000 14580 false false No definition available. No authoritative reference available. false 46 4 us-gaap_OtherSecuredFinancings us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 8102000000 8102 false false 2 false true 12539000000 12539 false false No definition available. No authoritative reference available. false 47 4 us-gaap_PayablesToBrokerDealersAndClearingOrganizationsAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 48 5 us-gaap_AccountsPayableCurrentAndNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 117058000000 117058 false false 2 false true 123617000000 123617 false false No definition available. No authoritative reference available. false 49 5 us-gaap_PayablesToBrokerDealersAndClearingOrganizations us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 5423000000 5423 false false 2 false true 1585000000 1585 false false No definition available. No authoritative reference available. false 50 5 us-gaap_InterestAndDividendsPayableCurrentAndNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2597000000 2597 false false 2 false true 3305000000 3305 false false No definition available. No authoritative reference available. false 51 4 us-gaap_OtherLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 20849000000 20849 false false 2 false true 16179000000 16179 false false No definition available. No authoritative reference available. false 52 4 us-gaap_LongTermDebt us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 193374000000 193374 false false 2 false true 179835000000 179835 false false No definition available. No authoritative reference available. false 53 4 us-gaap_Liabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 718682000000 718682 false false 2 false true 627308000000 627308 false false No definition available. No authoritative reference available. true 56 5 us-gaap_StockholdersEquityAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 57 6 us-gaap_PreferredStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 9597000000 9597 false false 2 false true 19168000000 19168 false false No definition available. No authoritative reference available. false 58 6 us-gaap_CommonStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 15000000 15 false false 2 false true 12000000 12 false false No definition available. No authoritative reference available. false 59 6 us-gaap_AdditionalPaidInCapital us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 8619000000 8619 false false 2 false true 459000000 459 false false No definition available. No authoritative reference available. false 60 6 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 35056000000 35056 false false 2 false true 36154000000 36154 false false No definition available. No authoritative reference available. false 61 6 us-gaap_CommonStockSharesHeldInEmployeeTrust us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 4064000000 4064 false false 2 false true 4312000000 4312 false false No definition available. No authoritative reference available. false 62 6 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -560000000 -560 false false 2 false true -420000000 -420 false false No definition available. No authoritative reference available. false 63 6 us-gaap_TreasuryStockValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true -6039000000 -6039 false false 2 false true -6620000000 -6620 false false No definition available. No authoritative reference available. false 64 6 us-gaap_CommonStockIssuedEmployeeStockTrust us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true -4064000000 -4064 false false 2 false true -4312000000 -4312 false false No definition available. No authoritative reference available. false 65 6 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 46688000000 46688 false false 2 false true 48753000000 48753 false false No definition available. No authoritative reference available. true 66 5 us-gaap_MinorityInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 6092000000 6092 false false 2 false true 703000000 703 false false No definition available. No authoritative reference available. false 67 5 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 52780000000 52780 false false 2 false true 49456000000 49456 false false No definition available. No authoritative reference available. true 68 4 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 true true 771462000000 771462 false false 2 true true 676764000000 676764 false false No definition available. No authoritative reference available. true false 2 62 false Millions UnKnown UnKnown false true