2.2.0.25falsefalse40308 - Disclosure - Investment Securities (Schedule of Activity in the Accretable Yield Related to Acquired Debt Securities) (Details)truefalseIn Millionsfalse1falsefalseUSDfalsefalse1/1/2010 - 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$5false0us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse279000000279falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan for loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that
the investor will be unable to collect all contractually required payments receivable.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 03-3
-Paragraph 16
-Subparagraph a(2)
falsefalse6false0us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldAccretionus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-45000000-45falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCurrent period recognition due to accretion of the excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan for loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which i
t is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 03-3
-Paragraph 16
-Subparagraph a(2)
falsefalse7false0stt_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesSalessttfalsecreditdurationCertain Loans Acquired In Transfer Accounted For As Debt Securities Salesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-220000000-220[1]falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCertain Loans Acquired In Transfer Accounted For As Debt Securities SalesNo authoritative reference available.falsefalse8false0stt_AvailableForSaleSecuritiesGrossUnrealizedLossCreditDeteriorationsttfalsedebitdurationAvailable for sale securities, gross unrealized loss, credit deteriorationfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-13000000-13falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAvailable for sale securities, gross unrealized loss, credit deteriorationNo authoritative reference available.falsefalse9false0us-gaap_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse10000001falsetrue
falsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan for loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 03-3
-Paragraph 16
-Subparagraph a(2)
falsefalse1
Associated with the December 2010 repositioning of the investment portfolio. 15Investment Securities (Schedule of Activity in the Accretable Yield Related to Acquired Debt Securities) (Details) (USD $)MillionsUnKnownUnKnownUnKnownfalsetrue
