1.0.0.3 false Statement Of Financial Position Unclassified - Deposit Based Operations (Parenthetical) (USD $) In Millions, except 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 5 3 stt_FairValueHeldToMaturityInvestmentSecuritiesPurchasedUnderMoneyMarketLiquidityFacility stt false debit instant monetary Fair Value, Held To Maturity Investment Securities Purchased Under Money Market Liquidity Facility false false false false false false false false false 1 true true 0 0 false false 2 true true 6100000000 6100 false false Fair Value, Held To Maturity Investment Securities Purchased Under Money Market Liquidity Facility No authoritative reference available. false 6 3 us-gaap_HeldToMaturitySecuritiesFairValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 20928000000 20928 false false 2 false true 14311000000 14311 false false No definition available. No authoritative reference available. false 7 3 us-gaap_LoansAndLeasesReceivableAllowance us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 79000000 79 false false 2 false true 18000000 18 false false No definition available. No authoritative reference available. false 8 3 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 true true 3046000000 3046 false false 2 true true 2758000000 2758 false false No definition available. No authoritative reference available. false 9 3 us-gaap_PreferredStockParOrStatedValuePerShare us-gaap true na instant decimal No definition available. false false false false false false false false true 1 true true 0 0 false false 2 true true 0 0 false false No definition available. No authoritative reference available. false 10 3 us-gaap_PreferredStockSharesAuthorized us-gaap true na instant shares No definition available. false false false false false false false false false 1 false true 3500000 3500000.00 false false 2 false true 3500000 3500000.00 false false No definition available. No authoritative reference available. false 11 3 us-gaap_PreferredStockSharesIssued us-gaap true na instant shares No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 20000 20000.00 false false No definition available. No authoritative reference available. false 12 3 us-gaap_PreferredStockSharesOutstanding us-gaap true na instant shares No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 20000 20000.00 false false No definition available. No authoritative reference available. false 13 3 us-gaap_CommonStockParOrStatedValuePerShare us-gaap true na instant decimal No definition available. false false false false false false false false true 1 true true 1 1 false false 2 true true 1 1 false false No definition available. No authoritative reference available. false 14 3 us-gaap_CommonStockSharesAuthorized us-gaap true na instant shares No definition available. false false false false false false false false false 1 false true 750000000 750000000.00 false false 2 false true 750000000 750000000.00 false false No definition available. No authoritative reference available. false 15 3 us-gaap_CommonStockSharesIssued us-gaap true na instant shares No definition available. false false false false false false false false false 1 false true 495365571 495365571.00 false false 2 false true 431976032 431976032.00 false false No definition available. No authoritative reference available. false 16 3 us-gaap_TreasuryStockShares us-gaap true na instant shares No definition available. false false false false false false false false false 1 false true 431832 431832.00 false false 2 false true 418354 418354.00 false false No definition available. No authoritative reference available. false false 2 12 false Millions NoRounding NoRounding false true