Fair Value Fair Value (Fair Value Inputs, Assets and Liabilities, Quantitative Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Assumptions, Expected Term	10 years 9 months 21 days
Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	6,820
Liabilities, Fair Value Disclosure	155
Fair Value, Inputs, Level 3 [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Expected Recovery	10.00%
Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	511
Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities, Credit Cards [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	119
Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities, Other [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	3,090
Fair Value, Inputs, Level 3 [Member] | Non-US Debt Securities, Other [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	314
Fair Value, Inputs, Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	50
Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	126
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	9
Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Asset-backed Securities, Student Loans [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Credit Spread Risk	1.20%
Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Asset-backed Securities, Credit Cards [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Credit Spread Risk	6.00%
Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Asset-backed Securities, Other [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Credit Spread Risk	1.20%
Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Non-US Debt Securities, Other [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	15.00%
Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | US States and Political Subdivisions Debt Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Credit Spread Risk	1.80%
Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Derivative Financial Instruments, Liabilities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Participant Redemptions	5.00%
Fair Value, Inputs, Level 3 [Member] | Option Model Approach Valuation Technique [Member] | Derivative Financial Instruments, Liabilities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Assumptions, Expected Volatility Rate	11.80%
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	127
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member] | Option Model Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Assumptions, Expected Volatility Rate	11.80%
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	632
Liabilities, Fair Value Disclosure	135
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	315
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities, Credit Cards [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	31
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities, Other [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	104
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Non-US Debt Securities, Other [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	5
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	50
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	126
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	9
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	315
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Asset-backed Securities, Credit Cards [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	31
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Asset-backed Securities, Other [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	104
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Non-US Debt Securities, Other [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	5
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | US States and Political Subdivisions Debt Securities [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	50
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	9
Significant Unobservable Inputs Readily Available [Member] | Fair Value, Inputs, Level 3 [Member] | Option Model Approach Valuation Technique [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	126
Significant Unobservable Inputs Readily Available [Member] | Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	127
Significant Unobservable Inputs Readily Available [Member] | Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member] | Option Model Approach Valuation Technique [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	127