Fair Value (Schedule of Availability of Significant Unobservable Inputs by Balance Sheet Classification) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Assets:
Investment securities available for sale	$ 99,174		$ 109,682
Asset-backed securities, student loans
Assets:
Investment securities available for sale	14,542	[1]	16,421	[1]
Asset-backed securities, credit cards
Assets:
Investment securities available for sale	8,210		9,986
Asset-backed securities, other
Assets:
Investment securities available for sale	5,064		4,677
Non-U.S. debt securities, mortgage-backed securities
Assets:
Investment securities available for sale	11,029		11,405
Non-U.S. debt securities, asset-backed securities
Assets:
Investment securities available for sale	5,390		6,218
Non-U.S. debt securities, other
Assets:
Investment securities available for sale	4,727		4,306
State and political subdivisions
Assets:
Investment securities available for sale	10,263		7,551
Collateralized mortgage obligations
Assets:
Investment securities available for sale	5,269		4,954
Other U.S.debt securities
Assets:
Investment securities available for sale	4,980		5,298
Pricing Methods with Significant Unobservable Market Inputs (Level 3)
Assets:
Assets, fair value disclosure	7,564		6,980
Liabilities:
Liabilities, fair value disclosure	26		115
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Derivative instruments, liabilities
Liabilities:
Derivative instruments, foreign exchange contracts, liabilities	17		106
Derivative instruments, other, liabilities	9		9
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Derivative instruments, assets
Assets:
Derivative instruments, foreign exchange contracts, assets	19		113
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | U.S. Treasury and federal agencies, mortgage-backed securities
Assets:
Investment securities available for sale	716		825
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, student loans
Assets:
Investment securities available for sale	423		588
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, credit cards
Assets:
Investment securities available for sale	24		67
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, other
Assets:
Investment securities available for sale	4,532		3,994
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. debt securities, mortgage-backed securities
Assets:
Investment securities available for sale	375		555
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. debt securities, asset-backed securities
Assets:
Investment securities available for sale	798		524
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. debt securities, other
Assets:
Investment securities available for sale	464		140
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | State and political subdivisions
Assets:
Investment securities available for sale	43		48
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Collateralized mortgage obligations
Assets:
Investment securities available for sale	162		117
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Other U.S.debt securities
Assets:
Investment securities available for sale	8		9
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member]
Assets:
Assets, fair value disclosure	191	[2]	343	[2]
Liabilities:
Liabilities, fair value disclosure	26	[2]	115	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Derivative instruments, liabilities
Liabilities:
Derivative instruments, foreign exchange contracts, liabilities	17	[2]	106	[2]
Derivative instruments, other, liabilities	9	[2]	9	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Derivative instruments, assets
Assets:
Derivative instruments, foreign exchange contracts, assets	19	[2]	113	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | U.S. Treasury and federal agencies, mortgage-backed securities
Assets:
Investment securities available for sale	0	[2]	0	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Asset-backed securities, student loans
Assets:
Investment securities available for sale	13	[2]	12	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Asset-backed securities, credit cards
Assets:
Investment securities available for sale	24	[2]	67	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Asset-backed securities, other
Assets:
Investment securities available for sale	92	[2]	103	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Non-U.S. debt securities, mortgage-backed securities
Assets:
Investment securities available for sale	0	[2]	0	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Non-U.S. debt securities, asset-backed securities
Assets:
Investment securities available for sale	0	[2]	0	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Non-U.S. debt securities, other
Assets:
Investment securities available for sale	0	[2]	0	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | State and political subdivisions
Assets:
Investment securities available for sale	43	[2]	48	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Collateralized mortgage obligations
Assets:
Investment securities available for sale	0	[2]	0	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Readily Available [Member] | Other U.S.debt securities
Assets:
Investment securities available for sale	0	[2]	0	[2]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member]
Assets:
Assets, fair value disclosure	7,373	[3]	6,637	[3]
Liabilities:
Liabilities, fair value disclosure	0	[3]	0	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Derivative instruments, liabilities
Liabilities:
Derivative instruments, foreign exchange contracts, liabilities	0	[3]	0	[3]
Derivative instruments, other, liabilities	0	[3]	0	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Derivative instruments, assets
Assets:
Derivative instruments, foreign exchange contracts, assets	0	[3]	0	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | U.S. Treasury and federal agencies, mortgage-backed securities
Assets:
Investment securities available for sale	716	[3]	825	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Asset-backed securities, student loans
Assets:
Investment securities available for sale	410	[3]	576	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Asset-backed securities, credit cards
Assets:
Investment securities available for sale	0	[3]	0	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Asset-backed securities, other
Assets:
Investment securities available for sale	4,440	[3]	3,891	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Non-U.S. debt securities, mortgage-backed securities
Assets:
Investment securities available for sale	375	[3]	555	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Non-U.S. debt securities, asset-backed securities
Assets:
Investment securities available for sale	798	[3]	524	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Non-U.S. debt securities, other
Assets:
Investment securities available for sale	464	[3]	140	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | State and political subdivisions
Assets:
Investment securities available for sale	0	[3]	0	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Collateralized mortgage obligations
Assets:
Investment securities available for sale	162	[3]	117	[3]
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Significant Unobservable Inputs Not Readily Available [Member] | Other U.S.debt securities
Assets:
Investment securities available for sale	$ 8	[3]	$ 9	[3]

[1] Substantially composed of securities guaranteed by the federal government with respect to at least 97% of defaulted principal and accrued interest on the underlying loans.

[2] Information with respect to these model-priced financial assets and liabilities is provided above in a separate table.

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