2.2.0.25falsefalse42101 - Disclosure - Expenses (Details)truefalsefalse1falsefalseUSDfalsefalse4/1/2010 - 6/30/2010
USD ($)
USD ($) / shares
$Duration_4_1_2010_To_6_30_2010http://www.sec.gov/CIK0000093751duration2010-04-01T00:00:002010-06-30T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2falsefalseUSDfalsefalse1/1/2009 - 12/31/2009
USD ($)
USD ($) / shares
$Duration_1_1_2009_To_12_31_2009http://www.sec.gov/CIK0000093751duration2009-01-01T00:00:002009-12-31T00:00:00Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$3falsefalseUSDfalsefalse1/1/2008 - 12/31/2008
USD ($)
USD ($) / shares
$Duration_1_1_2008_To_12_31_2008http://www.sec.gov/CIK0000093751duration2008-01-01T00:00:002008-12-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$4falsefalseUSDfalsefalse12/31/2007
USD ($)
$As_Of_12_31_2007http://www.sec.gov/CIK0000093751instant2007-12-31T00:00:000001-01-01T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$5false0stt_AggregatePreTaxSecuritiesLendingChargesttfalsedebitdurationAggregate Pre Tax Securities Lending Chargefalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse414000000414000000
falsetruefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00false<
/IsIndependantCurrency>falsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate Pre Tax Securities Lending ChargeNo authoritative reference available.falsefalse6false0us-gaap_LegalFeesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalse
false90000009000000falsefalsefalsefalsefalse2truefalsefalse250000000250000000falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9
falsefalse7false0stt_NetAssetValuePerUnderlyingCashCollateralPoolssttfalsenadurationNet asset value per underlying cash collateral poolsfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse11falsetruefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefal
sefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseEPSus-types:perShareItemTypedecimalNet asset value per underlying cash collateral poolsNo authoritative reference available.falsetrue8false0stt_OneTimeCashContributionToSsgaLendingFundssttfalsedebitdurationOne Time Cash Contribution To The SSgA Lending Fundsfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse330000000330000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryOne Time Cash Contribution To The SSgA Lending FundsNo authoritative reference available.falsefalse9false0stt_IncreaseInLitigationReservesttfalsedebitinstantIncrease in litigation reservefalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse
2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4truefalsefalse250000000250000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncrease in litigation reserveNo authoritative reference available.falsefalse10false0stt_Provi
sionForLegalFeessttfalsedebitdurationProvision for legal feesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse250000000250000000falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryProvision for legal feesNo authoritative reference available.falsefalse11false0stt_ElectedToPurchaseAssetAndMortgageBackedSecuritiessttfalsedebitinstantElected to purchase asset and mortgage backed securitiesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse24900000002490000000falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryElected to purchase asset and mortgage backed securitiesNo authoritative reference available.falsefalse12false0stt_AggregateAmountToImproveRatioOfMarketValueOfAccountsPortfolioHoldingssttfalsedebitdurationAggregate amount to improve the ratio of the market value of the accounts' portfolio holdingfalsefalsefalsefalse<
IsTuple>falsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse450000000450000000falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate amount to improve the ratio of the market value of the accounts' portfolio holdingNo authoritative reference available.falsefalse13false0stt_ProvisionForInvestmentSecuritiesAvailableForS
alesttfalsedebitinstantProvision for investment securities available-for-salefalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse450000000450000000falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryProvision for investment securities available-for-saleNo authoritati
ve reference available.falsefalse14false0stt_ReserveForDeclineInMarketValueOfCollateralSecuritiessttfalsedebitinstantReserve for decline in market value of collateral securitiesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse7500000075000000falsetruefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse200000000200000000falsetruefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryReserve for decline in market value of collateral securitiesNo authoritative reference available.falsefalse410Expenses (Details) (USD $)NoRoundingUnKnownNoRoundingUnKnownfalsetrue
