1.0.0.3 false Statement Of Shareholders Equity And Other Comprehensive Income (Parenthetical) (USD $) In Millions, except Per Share data 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 false 3 $ 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_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 true true 2158000000 2158 false false 2 true true -2866000000 -2866 false false 3 true true -276000000 -276 false false No definition available. No authoritative reference available. false 6 3 stt_OtherComprehensiveIncomeUnrealizedGainLossOnFairValueHedgesOfAvailableForSaleSecuritiesTax stt false debit duration monetary The tax effect from the appreciation or loss in value of the total of fair value hedges of available-for-sale securities... false false false false false false false false false 1 false true 82000000 82 false false 2 false true -116000000 -116 false false 3 false true -37000000 -37 false false The tax effect from the appreciation or loss in value of the total of fair value hedges of available-for-sale securities during the period being reported on. No authoritative reference available. false 7 3 us-gaap_OtherComprehensiveIncomeReclassificationAdjustmentForHeldToMaturityTransferredToAvailableForSaleSecuritiesTax us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -237000000 -237 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. No authoritative reference available. false 8 3 us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false true -96000000 -96 false false 2 false true -91000000 -91 false false 3 false true 62000000 62 false false No definition available. No authoritative reference available. false 9 3 us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 7000000 7 false false 2 false true -10000000 -10 false false 3 false true -7000000 -7 false false No definition available. No authoritative reference available. false 10 3 stt_RelatedTaxesOtherComprehensiveIncomeUnrealizedGainLossOnHedgesOfNetInvestmentsInNonUSSubsidiariesNetOfTax stt false credit duration monetary Related taxes, Other Comprehensive Income, Unrealized Gain (Loss) on Hedges of Net Investments in Non-US Subsidiaries, Net of... false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -4000000 -4 false false Related taxes, Other Comprehensive Income, Unrealized Gain (Loss) on Hedges of Net Investments in Non-US Subsidiaries, Net of Tax No authoritative reference available. false 11 3 us-gaap_OtherComprehensiveIncomeMinimumPensionLiabilityNetAdjustmentTax us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 23000000 23 false false 2 false true -48000000 -48 false false 3 false true 28000000 28 false false No definition available. No authoritative reference available. false 12 3 us-gaap_CommonStockDividendsPerShareDeclared us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 0.04 0.04 false false 2 true true 0.95 0.95 false false 3 true true 0.88 0.88 false false No definition available. No authoritative reference available. false 13 3 us-gaap_TreasuryStockAcquiredAverageCostPerShare us-gaap true na duration decimal No definition available. false false false false false false false false true 1 false false 0 0 false false 2 true true 75 75 false false 3 true true 75 75 false false No definition available. No authoritative reference available. false 14 3 us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true -52000000 -52 false false 2 true true 52000000 52 false false 3 true true 52000000 52 false false No definition available. No authoritative reference available. false false 3 10 false Millions UnKnown NoRounding false true