2.2.0.25falsefalse40606 - Disclosure - Investment Securities (Maturity Ranges of ARS Portfolio) (Details)truefalseIn Millions, unless otherwise specifiedfalse1falsefalseUSDfalsefalse12/31/2010
USD ($)
USD ($) / shares
$As_Of_12_31_2010http://www.sec.gov/CIK0001141391instant2010-12-31T00:00:000001-01-01T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0Unit16Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$3true0ma_HeldToMaturityDebtMaturitiesParAmountAbstractmafalsenadurationHeld to Maturity, Debt Maturities, Par Amount [Abstract]falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00false<
ShowCurrencySymbol>falsefalsefalsefalseOtherxbrli:stringItemTypestringHeld to Maturity, Debt Maturities, Par Amount [Abstract]falsefalse4false0ma_HeldToMaturityDebtMaturitiesWithinTenYearsParAmountmafalsedebitinstantHeld to Maturity, Debt Maturities, within Ten Years, Par Amountfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse40000004falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemon
etaryHeld to Maturity, Debt Maturities, within Ten Years, Par AmountNo authoritative reference available.falsefalse5false0ma_HeldToMaturityDebtMaturitiesAfterTenYearsThroughTwentyYearsParAmountmafalsedebitinstantHeld to Maturity, Debt Maturities, After Ten Years Through Twenty Years, Par Amountfalsefalsefalsefalsefalsefalsefalse<
IsBeginningBalance>falsefalsefalseverboselabel1truefalsefalse1100000011falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryHeld to Maturity, Debt Maturities, After Ten Years Through Twenty Years, Par AmountNo aut
horitative reference available.falsefalse6false0ma_HeldToMaturityDebtMaturitiesAfterTwentyYearsThroughThirtyYearsParAmountmafalsedebitinstantHeld to Maturity, Debt Maturities, After Twenty Years Through Thirty Years, Par Amountfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse8100000081falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryHeld to Maturity, Debt Maturities, After Twenty Years Through Thirty Years, Par AmountNo authoritative reference available.falsefalse7false0ma_HeldToMaturityDebtMaturitiesAfterThirtyYearsParAmountmafalsedebitinstantHeld to Maturity, Debt Maturities, After Thirty Years, Par Amountfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse2200000022falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryHeld to Maturity, Debt Maturities, After Thirty Years, Par AmountNo authoritative reference available.falsefalse8false0ma_HeldToMaturityDebtMaturitiesParAmountmafalsedebitinstantHeld to Maturity, Debt Maturities, Par Amountfalsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse118000000118falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryHeld to Maturity, Debt Maturities, Par AmountNo authoritative reference available.truefalse9true0ma_HeldToMaturityDebtMaturitiesPercentAbstractmafalsenadurationHeld to Maturity, Debt Maturities, Percent [Abstract]falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeld to Maturity, Debt Maturities, Percent [Abstract]falsefalse10false0ma_HeldToMaturityDebtMaturitiesWithinTenYearsRelativePercentFromTotalPortfoliomafalsenainstantHeld to Maturity, Debt Maturities, within Ten Years, Relative Percent From Total Portfoliofalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.030.03falsefalsefalsefalsefalseOtherus-types:percentItemTypepureHeld to Maturity, Debt Maturities, within Ten Years, Relative Percent From Total PortfolioNo authoritative reference available.falsefalse11false0ma_HeldToMaturityDebtMaturitiesAfterTenYearsThroughTwentyYearsRelativePercentFromTotalPortfoliomafalsenainstantHeld to Maturity, Debt Maturities, After Ten Years Through Twenty Years, Relative Percent From Total Portfoliofalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverb
oselabel1truetruefalse0.090.09falsefalsefalsefalsefalseOtherus-types:percentItemTypepureHeld to Maturity, Debt Maturities, After Ten Years Through Twenty Years, Relative Percent From Total PortfolioNo authoritative reference available.falsefalse12false0ma_HeldToMaturityDebtMaturitiesAfterTwentyYearsThroughThirtyYearsRelativePercentFromTotalPortfoliomafalsenainstantHeld to Maturity, Debt Maturities, After Twenty Years Through Thirty Years, Relative Percent From Total Portfoliofalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1<
/Id>truetruefalse0.690.69falsefalsefalsefalsefalseOtherus-types:percentItemTypepureHeld to Maturity, Debt Maturities, After Twenty Years Through Thirty Years, Relative Percent From Total PortfolioNo authoritative reference available.falsefalse13false0ma_HeldToMaturityDebtMaturitiesAfterThirtyYearsRelativePercentFromTotalPortfoliomafalsenainstantHeld to Maturity, Debt Maturities, After Thirty Years, Relative Percent From Total Portfoliofalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.190.19falsefalsefalsefalsefalseOtherus-types:percentItemTypepureHeld to Maturity, Debt Maturities, After Thirty Years, Relative Percent From Total PortfolioNo authoritative reference available.falsefalse14false0ma_HeldToMaturityDebtMaturitiesPercentmafalsenainstantHeld to Maturity, Debt Maturities, Percentfalsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truetruefalse11falsefalsefalsefalsefalseOtherus-types:percentItemTypepureHeld to Maturity, Debt Maturities, PercentNo authoritative reference available.truefalse112Investment Securities (Maturity Ranges of ARS Portfolio) (Details) (USD $)MillionsUnKnownUnKnownUnKnowntruetrue
