Investment Securities (Schedule of Contractual Maturities of Debt Securities) (Details) (USD $) In Millions	Jun. 30, 2011
Available for sale, Under 1 Year	$ 10,968
Available for sale, 1 to 5 Years	25,149
Available for sale, 6 to 10 Years	29,701
Available for sale, Over 10 Years	28,212
Held to maturity, Under 1 Year	1,737
Held to maturity, 1 to 5 Years	3,349
Held to maturity, 6 to 10 Years	799
Held to maturity, Over 10 Years	5,246
Asset-Backed Securities [Member] | U.S. Treasury and Federal Agencies [Member]
Held to maturity, Under 1 Year	7
Held to maturity, 1 to 5 Years
Held to maturity, 6 to 10 Years
Held to maturity, Over 10 Years	38
U.S. Treasury and Federal Agencies [Member]
Available for sale, Under 1 Year	3,057
Available for sale, 1 to 5 Years	11,150
Available for sale, 6 to 10 Years	10,086
Available for sale, Over 10 Years	4,453
U.S. Treasury and Federal Agencies [Member] | Direct Obligations [Member]
Available for sale, Under 1 Year	3,167
Available for sale, 1 to 5 Years	2,093
Available for sale, 6 to 10 Years	1,533
Available for sale, Over 10 Years	605
U.S. Treasury and Federal Agencies [Member] | Student Loans [Member]
Available for sale, Under 1 Year	119
Available for sale, 1 to 5 Years	4,055
Available for sale, 6 to 10 Years	7,884
Available for sale, Over 10 Years	3,862
U.S. Treasury and Federal Agencies [Member] | Credit Cards [Member]
Available for sale, Under 1 Year	1,810
Available for sale, 1 to 5 Years	6,229
Available for sale, 6 to 10 Years	1,829
Available for sale, Over 10 Years
U.S. Treasury and Federal Agencies [Member] | Other Asset-Backed Securities [Member]
Available for sale, Under 1 Year	139
Available for sale, 1 to 5 Years	664
Available for sale, 6 to 10 Years	361
Available for sale, Over 10 Years	149
U.S. Treasury and Federal Agencies [Member] | Collateralized Mortgage Backed Securities [Member]
Available for sale, Under 1 Year	4
Available for sale, 1 to 5 Years	1,192
Available for sale, 6 to 10 Years	10,415
Available for sale, Over 10 Years	13,924
Held to maturity, Under 1 Year	5
Held to maturity, 1 to 5 Years	75
Held to maturity, 6 to 10 Years	80
Held to maturity, Over 10 Years	172
U.S. Treasury and Federal Agencies [Member] | Residential, Subprime, Financing Receivable [Member]
Available for sale, Under 1 Year	989
Available for sale, 1 to 5 Years	202
Available for sale, 6 to 10 Years	12
Available for sale, Over 10 Years	442
Asset-Backed Securities [Member] | Non-U.S. Debt Securities [Member]
Available for sale, Under 1 Year	68
Available for sale, 1 to 5 Years	2,003
Available for sale, 6 to 10 Years	3,487
Available for sale, Over 10 Years	543
Held to maturity, Under 1 Year
Held to maturity, 1 to 5 Years	45
Held to maturity, 6 to 10 Years	44
Held to maturity, Over 10 Years
Non-U.S. Debt Securities [Member]
Held to maturity, Under 1 Year	1,253
Held to maturity, 1 to 5 Years	1,383
Held to maturity, 6 to 10 Years	350
Held to maturity, Over 10 Years	3,827
Non-U.S. Debt Securities [Member] | Non-U.S. Debt Securities [Member]
Available for sale, Under 1 Year	3,976
Available for sale, 1 to 5 Years	5,030
Available for sale, 6 to 10 Years	3,854
Available for sale, Over 10 Years	7,286
Non-U.S. Debt Securities [Member] | Other Non-U.S. Debt Securities [Member]
Available for sale, Under 1 Year	53
Available for sale, 1 to 5 Years	938
Available for sale, 6 to 10 Years	128
Available for sale, Over 10 Years	1
Held to maturity, Under 1 Year
Held to maturity, 1 to 5 Years	454
Held to maturity, 6 to 10 Years	306
Held to maturity, Over 10 Years	22
Non-U.S. Debt Securities [Member] | Government Securities [Member]
Available for sale, Under 1 Year	3,545
Available for sale, 1 to 5 Years
Available for sale, 6 to 10 Years
Available for sale, Over 10 Years
Non-U.S. Debt Securities [Member] | Collateralized Mortgage Backed Securities [Member]
Available for sale, Under 1 Year	310
Available for sale, 1 to 5 Years	2,089
Available for sale, 6 to 10 Years	239
Available for sale, Over 10 Years	6,742
Held to maturity, Under 1 Year	1,253
Held to maturity, 1 to 5 Years	884
Held to maturity, 6 to 10 Years
Held to maturity, Over 10 Years	3,805
State and Political Subdivisions [Member]
Available for sale, Under 1 Year	457
Available for sale, 1 to 5 Years	2,634
Available for sale, 6 to 10 Years	2,632
Available for sale, Over 10 Years	1,024
Held to maturity, Under 1 Year	57
Held to maturity, 1 to 5 Years	61
Held to maturity, 6 to 10 Years
Held to maturity, Over 10 Years	1
Collateralized Mortgage Obligations [Member]
Available for sale, Under 1 Year	76
Available for sale, 1 to 5 Years	1,206
Available for sale, 6 to 10 Years	494
Available for sale, Over 10 Years	878
Held to maturity, Under 1 Year	415
Held to maturity, 1 to 5 Years	1,830
Held to maturity, 6 to 10 Years	369
Held to maturity, Over 10 Years	1,208
Other U.S. Debt Securities [Member]
Available for sale, Under 1 Year	231
Available for sale, 1 to 5 Years	1,844
Available for sale, 6 to 10 Years	687
Available for sale, Over 10 Years	$ 42