Fair Value Fair Value (Fair Value Inputs, Assets and Liabilities, Quantitative Information) (Details) (Fair Value, Inputs, Level 3 [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	6,980
Liabilities, Fair Value Disclosure	115
Derivative Financial Instruments, Liabilities [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	106
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	9
Derivative Financial Instruments, Assets [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	113
Asset-backed Securities, Student Loans [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	588
Asset-backed Securities, Credit Cards [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	67
Asset-backed Securities, Other [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	3,994
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	48
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	6.70%
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	6.70%
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	7.10%
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	1.50%
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	1.90%
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	9.80%
Option Model Approach Valuation Technique [Member] | Derivative Financial Instruments, Assets [Member] | Weighted Average [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Assumptions, Expected Volatility Rate	9.80%
Significant Unobservable Inputs Readily Available [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	343	[1]
Liabilities, Fair Value Disclosure	115	[1]
Significant Unobservable Inputs Readily Available [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	106	[1]
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	9	[1]
Significant Unobservable Inputs Readily Available [Member] | Derivative Financial Instruments, Assets [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	113	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	12	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed Securities, Credit Cards [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	67	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed Securities, Other [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Available-for-sale Securities, Fair Value Disclosure	103	[1]
Significant Unobservable Inputs Readily Available [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	48	[1]
Significant Unobservable Inputs Readily Available [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] | 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	12
Significant Unobservable Inputs Readily Available [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	67
Significant Unobservable Inputs Readily Available [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	103
Significant Unobservable Inputs Readily Available [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	48
Significant Unobservable Inputs Readily Available [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	106
Significant Unobservable Inputs Readily Available [Member] | Option Model Approach Valuation Technique [Member] | Derivative Financial Instruments, Assets [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	113

[1] Information with respect to these model-priced financial assets and liabilities is provided in the preceding table.