Fair Value Fair Value (Schedule of Availability of Significant Unobservable Inputs by Balance Sheet Classification) (Details) (Fair Value, Inputs, Level 3 [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Assets, Fair Value Disclosure	$ 6,980
Liabilities, Fair Value Disclosure	115
Derivative Financial Instruments, Liabilities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [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, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	113
Mortgage Backed Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	825
Asset-backed Securities, Student Loans [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	588
Asset-backed Securities, Credit Cards [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	67
Asset-backed Securities, Other [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	3,994
Non-US Debt Securities, Mortgage-Backed Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	555
Non-US Debt Securities, Asset-Backed Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	524
Non-US Debt Securities, Other [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	140
US States and Political Subdivisions Debt Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	48
Collateralized Mortgage Obligations [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	117
Other U.S. Debt Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	9
Significant Unobservable Inputs Readily Available [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [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, Measurements, Availability of Significant Unobservable Inputs [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, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	113	[1]
Significant Unobservable Inputs Readily Available [Member] | Mortgage Backed Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0
Significant Unobservable Inputs Readily Available [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [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, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	67	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed Securities, Other [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	103	[1]
Significant Unobservable Inputs Readily Available [Member] | Non-US Debt Securities, Mortgage-Backed Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0	[1]
Significant Unobservable Inputs Readily Available [Member] | Non-US Debt Securities, Asset-Backed Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0	[1]
Significant Unobservable Inputs Readily Available [Member] | Non-US Debt Securities, Other [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0	[1]
Significant Unobservable Inputs Readily Available [Member] | US States and Political Subdivisions Debt Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	48	[1]
Significant Unobservable Inputs Readily Available [Member] | Collateralized Mortgage Obligations [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0	[1]
Significant Unobservable Inputs Readily Available [Member] | Other U.S. Debt Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0	[1]
Significant Unobservable Inputs Not Readily Available [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Assets, Fair Value Disclosure	6,637	[2]
Liabilities, Fair Value Disclosure	0	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0
Significant Unobservable Inputs Not Readily Available [Member] | Derivative Financial Instruments, Assets [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Mortgage Backed Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	825	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	576	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Asset-backed Securities, Credit Cards [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Asset-backed Securities, Other [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	3,891	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Non-US Debt Securities, Mortgage-Backed Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	555	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Non-US Debt Securities, Asset-Backed Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	524	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Non-US Debt Securities, Other [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	140	[2]
Significant Unobservable Inputs Not Readily Available [Member] | US States and Political Subdivisions Debt Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Collateralized Mortgage Obligations [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	117	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Other U.S. Debt Securities [Member]
Fair Value, Measurements, Availability of Significant Unobservable Inputs [Line Items]
Available-for-sale Securities, Fair Value Disclosure	$ 9	[2]

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

[2] Fair value for these financial assets is measured using non-binding broker or dealer quotes.