Created by potrace 1.16, written by Peter Selinger 2001-2019beatandraise.com

STATE STREET CORP

Statements

Exhibits

d10k.htmdex1013.htmdex1015.htmdex1016.htmdex1020.htmdex12.htmdex21.htmdex23.htmdex311.htmdex312.htmdex32.htmstt-20101231.xmlR19.xmlR143.xmlR131.xmlR44.xmlR80.xmlR97.xmlR35.xmlR106.xmlR120.xmlR112.xmlR51.xmlR116.xmlR29.xmlR11.xmlR10.xmlR109.xmlR60.xmlR30.xmlR100.xmlR139.xmlR54.xmlR8.xmlR36.xmlR41.xmlR79.xmlR66.xmlR72.xmlR58.xmlR22.xmlR89.xmlR74.xmlR31.xmlR45.xmlR133.xmlR138.xmlR43.xmlR73.xmlR124.xmlR49.xmlR105.xmlR53.xmlR92.xmlR18.xmlR107.xmlR86.xmlR98.xmlR123.xmlR94.xmlR32.xmlR108.xmlR82.xmlR67.xmlR57.xmlR12.xmlR3.xmlR113.xmlR142.xmlR134.xmlR14.xmlR125.xmlR90.xmlR48.xmlR78.xmlR15.xmlR24.xmlR69.xmlR119.xmlR20.xmlR136.xmlR4.xmlR114.xmlR83.xmlR77.xmlR27.xmlR101.xmlR39.xmlR127.xmlR75.xmlR128.xmlR81.xmlR96.xmlR68.xmlR118.xmlR135.xmlR70.xmlR50.xmlR33.xmlR16.xmlR28.xmlR102.xmlR76.xmlR52.xmlR62.xmlR122.xmlR130.xmlR9.xmlR6.xmlR61.xmlR88.xmlR91.xmlR85.xmlR5.xmlR23.xmlR115.xmldefnref.xmlR95.xmlR84.xmlR121.xmlR46.xmlR21.xmlR99.xmlR87.xmlR13.xmlR34.xmlR26.xmlR93.xmlR59.xmlR129.xmlR64.xmlR1.xmlR2.xmlR132.xmlR103.xmlR37.xmlR63.xmlR56.xmlR144.xmlR111.xmlFinancial_Report.xlsR110.xmlR55.xmlR47.xmlR141.xmlR38.xmlR25.xmlR7.xmlR117.xmlR65.xmlR137.xmlR126.xmlR40.xmlR71.xmlR42.xmlR17.xmlR140.xmlR104.xml

Graphics

g129640g17i54.jpgg129640g29z78.jpgg129640g82i98.jpg
NotesSupport
aboutterms
2.2.0.25truefalse41402 - Disclosure - Fair Value (Fair Value Measurements Using Significant Unobservable Inputs) (Details)truefalseIn Millionsfalse1falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Student Loans [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_201052432842http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseStudent Loans [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_StudentLoansMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12 Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Student Loans [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009865http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseStudent Loans [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_StudentLoansMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse0 0falsefalsefalsefalsefalse1falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Student Loans [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_201052432842http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseStudent Loans [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_StudentLoansMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12 Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Student Loans [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009865http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseStudent Loans [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_StudentLoansMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse2false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus- gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse31750000003175falsetruefalsefalsefalse2truefalsefalse74750000007475falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse3false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse90000009falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse4false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel 1truefalsefalse8100000081falsefalsefalsefalsefalse2truefalsefalse226000000226falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse5false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-317000000-317falsefalsefalsefalsefalse2truefalsefalse-188000000-188falsefalsefalsefalse< /hasSegments>falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse6false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-1714000000-1714falsefalsefalsefalsefalse2truefalsefalse-4338000000-4338falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse7false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse12340000001234falsefalsefalsefalsefalse2truefalsefalse31750000003175falsefalsefalsefalsefa lseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse8false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails< Id>1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Credit Cards [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_20105243283http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseCredit Cards [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_CreditCardsMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Credit Cards [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009862http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseCredit Cards [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_CreditCardsMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse9false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse327000000327falsefalsefalsefalsefalse2truefalsefalse2400000024falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation p urposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse10false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse1700000017falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefals eMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse11false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-17000000-17falsefalsefalsefalsefalse2truefalsefalse1500000015falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse12false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-31000000-31falsefalsefalsefalsefalse2truefalsefalse235000000235falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse13false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-268000000-268falsefalsefalsefalsefalse2truefalsefalse5300000053falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse14false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse2800000028falsefalsefalsefalsefalse2truefalsefalse327000000327falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse15false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse5falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Sub-Prime [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_201052432843http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseSub-Prime [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_SubPrimeMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$6falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Sub-Prime [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009866http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseSub-Prime [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_SubPrimeMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse16false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus- gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse30000003false falsefalsefalsefalse2truefalsefalse50000005falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginn ing and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse17false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse10000001falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse< /hasScenarios>Monetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse18false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-2000000-2falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse19false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsef alsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse20false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-4000000-4falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse21false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse30000003falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse22false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse7falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Other Asset-Backed Securities [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_20105243284http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseOther Asset-Backed Securities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_OtherAssetBackedSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$8falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Other Asset-Backed Securities [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009864http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseOther Asset-Backed Securities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_OtherAssetBackedSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse23false0us-gaap_FairValueMeasurementWithUnobservab leInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse18840000001884falsefalsefalsefalsefalse2truefalsefalse337000000337falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significa nt unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse24false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse9000000090falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefals eMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse25false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse118000000118falsefalsefalsefalsefalse2truefalsefalse4200000042falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse26false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-771000000-771falsefalsefalsefalsefalse2truefalsefalse241000000241falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse27false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-301000000-301falsefalsefalsefalsefalse2truefalsefalse12640000001264falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse28false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse10200000001020falsefalsefalsefalsefalse2truefalsefalse18840000001884falsefalsefalsefalsef alseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse29false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse9falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : State and Political Subdivisions [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_201074http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseState and Political Subdivisions [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_USStatesAndPoliticalSubdivisionsMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$10falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : State and Political Subdivisions [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_20098610http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseState and Political Subdivisions [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_USStatesAndPoliticalSubdivisionsMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse30false0us-gaap_FairValueMeasu rementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse20000002falsefalsefalsefalsefalse2truefalsefalse10000001falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse31false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefa lsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse32false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-1000000-1falsefalsefalsefalsefalse2truefalsefalse20000002falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse33false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse4900000049falsefalsefalsefalsefalse2truefalsefalse-1000000-1falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse34false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse5000000050falsefalsefalsefalsefalse2truefalsefalse20000002falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse35false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse11falsefalseUSDtruefalse{invest_InvestmentAxis} : Collateralized Mortgage Obligations [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_200983http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseCollateralized Mortgage Obligations [Member]invest_InvestmentAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CollateralizedMortgageObligationsMemberinvest_InvestmentAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217< /MeasureSchema>USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse36false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptru edebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse40000004falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse37false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-119000000-119falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse38false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-6000000-6falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse39false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse324000000324falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse40false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-4000000-4falsefalsefalsefalsefalse< /hasScenarios>Monetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse41false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse199000000199falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse42false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse12falsefalseUSDtruefalse{invest_InvestmentAxis} : Collateralized Mortgage Obligations [Member] {us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Mortgage-Backed Securities [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_20106http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseCollateralized Mortgage Obligations [Member]invest_InvestmentAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CollateralizedMortgageObligationsMemberinvest_InvestmentAxisexplicitMemberfalsefalseMortgage-Backed Securities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MortgageBackedSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse43false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse199000000199falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse44false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-35000000-35falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefa lseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse45false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse60000006falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse46false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse362000000362falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse47false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-173000000-173falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefa lseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse48false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse359000000359falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse49false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse13falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Asset-Backed Securities [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_201052432844http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseAsset-Backed Securities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_AssetBackedSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$14falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Asset-Backed Securities [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009867http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseAsset-Backed Securities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_AssetBackedSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse50false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliat ionRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse53890000005389falsefalsefalsefalsefalse2truefalsefalse78410000007841falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable i nputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse51false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse117000000117falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefa lseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse52false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse182000000182falsefalsefalsefalsefalse2truefalsefalse281000000281falsefalsefalsefalse< hasScenarios>falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse53false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-1119000000-1119falsefalsefalsefalsefalse2truefalsefalse288000000288falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse54false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-2287000000-2287falsefalsefalsefalsefalse2truefalsefalse-3021000000-3021falsefalsefalsefalse< hasScenarios>falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse55false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse22820000002282falsefalsefalsefalsefalse2truefalsefalse53890000005389falsefalsefalsefalsef alseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse56false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse15falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Trading Account Assets [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009869http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseTrading Account Assets [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_TradingAccountAssetsMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse57false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationR ecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse366000000366falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) w hich is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse58false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefa lsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse59false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsef alsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse60false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-366000000-366falsefalsefalsefalsefa lseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse61false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse62false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse16falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Mortgage-Backed Securities Issued by U.S. Government Sponsored Enterprises [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_201052432847http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseMortgage-Backed Securities Issued by U.S. Government Sponsored Enterprises [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis explicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$17falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Mortgage-Backed Securities Issued by U.S. Government Sponsored Enterprises [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009868http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseMortgage-Backed Securities Issued by U.S. Government Sponsored Enterprises [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexpli citMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse63false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefa lse5800000058falsefalsefalsefalsefalse2truefalsefalse20000002falsefalsefalsefalsefalseMonetaryxb rli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse64false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-1000000-1falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefals eMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse65false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-1000000-1falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse66false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse659000000659falsefalsefalsefalsefalse2truefalsefalse5600000056falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse67false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-42000000-42falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse68false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse673000000673falsefalsefalsefalsefalse2truefalsefalse5800000058falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse69false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse18falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Foreign Government Debt Securities [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_201052432846http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseForeign Government Debt Securities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignGovernmentDebtSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$19falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Foreign Government Debt Securities [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009812http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseForeign Government Debt Securities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignGovernmentDebtSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse70false0us-gaap_FairValueM easurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse17770000001777falsefalsefalsefalsefalse2truefalsefalse10110000001011falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse71false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse6000000060falsefalsefalsefalsefalse2truefalsefalse1800000018falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse72false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse8400000084falsefalsefalsefalsefalse2truefalsefalse10510000001051falsefalsefalsefalse< hasScenarios>falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse73false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse15510000001551falsefalsefalsefalsefalse2truefalsefalse10710000001071falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse74false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-1332000000-1332falsefalsefalsefalsefalse2truefalsefalse-1374000000-1374falsefalsefalsefalse< hasScenarios>falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse75false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse21400000002140falsefalsefalsefalsefalse2truefalsefalse17770000001777falsefalsefalsefalsef alseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse76false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse20falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Fair Value Measurement With Unobservable Inputs Other U.S. Debt Securities [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009863http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseFair Value Measurement With Unobservable Inputs Other U.S. Debt Securities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_FairValueMeasurementWithUnobservableInputsOtherUsDebtSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMe mberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$21falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Fair Value Measurement With Unobserv able Inputs Other U.S. Debt Securities [Member] 12/31/2010 USD ($) $As_Of_12_31_2010323http://www.sec.gov/CIK0000093751instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseFair Value Measurement With Unobservable Inputs Other U.S. Debt Securities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_FairValueMeasurementWithUnobservableInputsOtherUsDebtSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse77false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse30000003falsefalsefalsefalsefalse2truefalsefalse2800000028falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse78false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefa lsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse79false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-25000000-25falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse80false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefalse< hasScenarios>falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse81false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse30000003falsefalsefalsefalsefalse2truefalsefalse30000003falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse82false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse22falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Total Investment Securities Available-For-Sale [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_201052432845http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseTotal Investment Securities Available-For-Sale [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_AvailableforsaleSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$23falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Total Investment Securities Available-For-Sale [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009811http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseTotal Investment Securities Available-For-Sale [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_AvailableforsaleSecuritiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMember Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse83false0 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse74280000007428falsefalsefalsefalsefalse2truefalsefalse88870000008887falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element r epresents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse84false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse141000000141falsefalsefalsefalsefalse2truefalsefalse-101000000-101falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse85false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse271000000271falsefalsefalsefalsefalse2truefalsefalse13260000001326falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse86false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse14520000001452falsefalsefalsefalsefalse2truefalsefalse17160000001716falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse87false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-3785000000-3785falsefalsefalsefalsefalse2truefalsefalse-4400000000-4400falsefalsefalsefalse< hasScenarios>falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse88false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse55070000005507falsefalsefalsefalsefalse2truefalsefalse74280000007428falsefalsefalsefalsef alseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse89false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails 1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse24falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Other Assets [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_20105http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseOther Assets [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_OtherAssetsMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$25falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Other Assets [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009723http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseOther Assets [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_OtherAssetsMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse90false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse128000000128falsefalsefalsefalsefalse2truefalsefalse760000000760falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconcili ation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse91false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-55000000-55falsefalsefalsefalsefalse2truefalsefalse-366000000-366falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse92false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse93false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse181000000181falsefalsefalsefalsefalse2truefalsefalse-266000000-266falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse94false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefalse< hasScenarios>falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse95false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse254000000254falsefalsefalsefalsefalse2truefalsefalse128000000128falsefalsefalsefalsefalse Monetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse96false0stt_ChangeInUnrealizedGainsLossesRelatedToFinancialInstrumentssttfalsecreditdurationChange In Unrealized Gains Losses Related To Financial Instrumentsfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel< Cells>1truefalsefalse-41000000-41falsefalsefalsefalsefalse2truefalsefalse-71000000-71falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryChange In Unrealized Gains Losses Related To Financial InstrumentsNo authoritative reference available.falsefalse97false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse26falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Other Liabilities [Member] {us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxis} : Fair Value Measurement With Unobservable Inputs Other Liabilities [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_2010224http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseOther Liabilities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_OtherLiabilitiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberfalsefalseFair Value Measurement With Unobservable Inputs Other Liabilities [Member]us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_FairValueMeasurementWithUnobservableInputsOtherLiabilitiesMemberus-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse98false0stt_FairValueLiabilitiessttfalsecreditinstantFair Value, Liabilitiesfalsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse147000000147falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFair Value, LiabilitiesNo authoritative reference available.falsefalse99false0us-gaap_Fair ValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarningsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-72000000-72falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse100false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlementsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse194000000194falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse101false0stt_FairValueLiabilitiessttfalsecreditinstantFair Value, Liabilitiesfalsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse269000000269falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFair Value, LiabilitiesNo authoritative reference available.falsefalse102false0stt_ChangeInUnrealizedGainsLossesRelatedToFinancialInstrumentssttfalsecreditdurationChange In Unrealized Gains Losses Related To Financial Instrumentsfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse-36000000-36falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryChange In Unrealized Gains Losses Related To Financial InstrumentsNo authoritative reference available.falsefalse103false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse27falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Total Assets [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_2010222http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseTotal Assets [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_FairValueMeasurementWithUnobservableInputsAssetsMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$28falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Total Assets [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_200924http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseTotal Assets [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_FairValueMeasurementWithUnobservableInputsAssetsMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse104false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurri ngBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse75560000007556falsefalsefalsefalsefalse2truefalsefalse1001300000010013falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (L evel 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse105false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarningsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse8600000086falsefalsefalsefalsefalse2truefalsefalse-467000000-467falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse106false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse271000000271falsefalsefalsefalsefalse2truefalsefalse13260000001326falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse107false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse16330000001633falsefalsefalsefalsefalse2truefalsefalse14500000001450falsefalsefalsefals efalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse108false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-3785000000-3785falsefalsefalsefalsefalse2truefalsefalse-4766000000-4766falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse109false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse57610000005761falsefalsefalsefalsefalse2truefalsefalse75560000007556falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse110false0stt_ChangeInUnrealizedGainsLossesRelatedToFinancialInstrumentssttfalsecreditdurationChange In Unrealized Gains Losses Related To Financial Instrumentsfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel 1truefalsefalse-41000000-41falsefalsefalsefalsefalse2truefalsefalse-71000000-71falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryChange In Unrealized Gains Losses Related To Financial InstrumentsNo authoritative reference available.falsefalse111false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse0 0falsefalsefalsefalsefalse29falsefalseUSDtruefalse{us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis} : Total Liabilities [Member] {us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxis} : Fair Value Measurement With Unobservable Inputs Liabilities [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_2010223http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseTotal Liabilities [Member]us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_TotalLiabilitiesMemberus-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxisexplicitMemberfalsefalseFair Value Measurement With Unobservable Inputs Liabilities [Member]us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_FairValueMeasurementWithUnobservableInputsLiabilitiesMemberus-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD< CurrencySymbol>$OthernaNo definition available.No authoritative reference available.falsefalse112false0stt_FairValueLiabilitiessttfalsecreditinstantFair Value, Liabilitiesfalsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse147000000147falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFair Value, LiabilitiesNo authoritative reference available.falsefalse113false0us-gaap_FairValueMeasurementWithUnobs ervableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarningsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-72000000-72falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the p eriod (realized and unrealized), arising from liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse114false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlementsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse194000000194falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse115false0stt_FairValueLiabilitiessttfalsecreditinstantFair Value, Liabilitiesfalsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse269000000269falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFair Value, LiabilitiesNo authoritative reference available.falsefalse116false0stt_ChangeInUnrealizedGainsLossesRelatedToFinancialInstrumentssttfalsecreditdurationChange In Unrealized Gains Losses Related To Financial Instrumentsfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse-36000000-36falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryChange In Unrealized Gains Losses Related To Financial InstrumentsNo authoritative reference available.falsefalse117false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse30falsefalseUSDtruefalse{us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxis} : Fair Value Measurement With Unobservable Inputs O ther Liabilities [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_20095http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseFair Value Measurement With Unobservable Inputs Other Liabilities [Member]us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_FairValueMeasurementWithUnobservableInputsOtherLiabilitiesMemberus-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxisexplicit MemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse118false0stt_FairValueLiabilitiessttfalsecreditinstantFair Value, Liabilitiesfalsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse857000000857falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFair Value, LiabilitiesNo authoritative reference available.falsefalse119false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarningsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-445000000-445falsefalse< /ShowCurrencySymbol>falsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse120false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncomeus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsef alsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse121false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlementsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselab el1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-265000000-265falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse122false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel< FootnoteIndexer />1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse123false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse147000000147falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse124false0stt_ChangeInUnrealizedGainsLossesRelatedToFinancialInstrumentssttfalsecreditdurationChange In Unrealized Gains Losses Related To Financial Instrumentsfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel 1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-116000000-116falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryChange In Unrealized Gains Losses Related To Financial InstrumentsNo authoritative reference available.falsefalse125false0natruenanaNo definition available.falsetruefalsefalsefalsefalse falsefalsefalsefalsehttp://www.statestreet.com/taxonomy/role/disclosurefairvaluefairvaluemeasurementsusingsignificantunobservableinputsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse31falsefalseUSDtruefalse{us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxis} : Fair Value Measurement With Unobservable Inputs Liabilities [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_200932http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseFair Value Measurement With Unobservable Inputs Liabilities [Member]us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxisxbrldihttp://xbrl.org/2006/xbrldistt_FairValueMeasurementWithUnobservableInputsLiabilitiesMemberus-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityTypeAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse126false0stt_FairValueLiabilitiessttfalsecreditinstantFair Value, Liabilitiesfalsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse857000000857falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFair Value, Li abilitiesNo authoritative reference available.falsefalse127false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarningsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-445000000-445falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse128false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncomeus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsef alsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents total gains or losses for the period (realized and unrealized), arising from liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) falsefalse129false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlementsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselab el1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-265000000-265falsefalsefalsefalse falseMonetaryxbrli:monetaryItemTypemonetaryThis element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) falsefalse130false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNetus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel< FootnoteIndexer />1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00&nbsp;falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(3) falsefalse131false0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse147000000147falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c falsefalse132false0stt_ChangeInUnrealizedGainsLossesRelatedToFinancialInstrumentssttfalsecreditdurationChange In Unrealized Gains Losses Related To Financial Instrumentsfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel 1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse-116000000-116falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryChange In Unrealized Gains Losses Related To Financial InstrumentsNo authoritative reference available.falsefalse2132Fair Value (Fair Value Measurements Using Significant Unobservable Inputs) (Details) (USD $)MillionsUnKnownUnKnownUnKnownfalsetrue