2.2.0.25falsefalse40401 - Disclosure - Loans and Leases (Narrative) (Details)truefalsefalse1falsefalseUSDfalsefalse1/1/2010 - 12/31/2010 USD ($) USD ($) / shares $Duration_1_1_2010_To_12_31_2010http://www.sec.gov/CIK0000093751duration2010-01-01T00:00:002010-12-31T00:00:00Unit15Standardhttp://xbrl.us/us-types/2009-01-31sqftxbrlus0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit14Dividehttp://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/iso4217USDiso42170Unit14Divide http://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$5false0stt_AggregateShortDurationAdvancessttfalsedebitdurationAggregate Short-Duration advancesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse26300000002630000000falsetruefalsefalsefalse2truefalsefalse20700000002070000000falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate Short-Duration advancesNo authoritative reference availabl e.falsefalse6false0stt_RevolvingCreditFacilityWithBorrowersttfalsedebitdurationRevolving Credit Facility With Borrowerfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse180000000180000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryRevolving Credit Facility With BorrowerNo authoritative reference available.falsefalse7false0us-gaap_LineOfCreditFacilityAmountOutstandingus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse160000000160000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAmount borrowed under the credit facility as of the balance-sheet date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 falsefalse8false0stt_AggregateLoanToBorrowersttfalsedebitdurationAggregate Loan To The Borrowerfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalse false345000000345000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse Monetaryxbrli:monetaryItemTypemonetaryAggregate Loan To The BorrowerNo authoritative reference available.falsefalse9false0stt_AcquiredCommercialRealEstateLoansttfalsedebitinstantAcquired Commercial Real Estate Loanfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse1600000016000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAcquired Commercial Real Estate LoanNo authoritative reference available.falsefalse11false0stt_AggregateOfDebtRestructuringssttfalsecreditdurationAggregate of debt restructuringsfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse307000000307000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate of debt restructuringsNo authoritative reference available.falsefalse12false0stt_LoansOrLeasesContractuallyPastDueDayssttfalsenadurationLoans or leases contractually past-due daysfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse9090falsefalsefalsefalsefalse2truefalsefalse9090falsefalsefalsefalsefalseOtherxbrli:integerItemTypeintegerLoans or leases contractually past-due daysNo authoritative reference available.falsefalse13false0stt_NonAccrualStatusPrincipalInterestPaymentsPastDueDayssttfalsenadurationNon-accrual status principal interest payments past due daysfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truef alsefalse6060falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:integerItemTypeintegerNon-accrual status principal interest payments past due daysNo authoritative reference available.falsefalse14false0stt_CommercialRealEstateLoansOnNonAccrualStatussttfalsecreditinstantCommercial real estate loans on non-accrual statusfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse20000002000000falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCommercial real estate loans on non-accrual statusNo authoritative reference available.falsefalse29Loans and Leases (Narrative) (Details) (USD $)NoRoundingUnKnownUnKnownUnKnowntruetrue