Loans and Allowance for Credit Losses (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	$ 7,523		$ 7,523		$ 7,952
Unpaid Principal Balance	12,538		12,538		10,821
Valuation Allowance	926		926		1,005
Commitments to Lend Additional Funds	106		106		144
Average recorded investment	7,703	6,785	7,810	6,649
Interest income recognized	79	51	142	101
Commercial Loan [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	443		443		657
Unpaid Principal Balance	1,518		1,518		1,437
Valuation Allowance	55		55		62
Commitments to Lend Additional Funds	74		74		68
Average recorded investment	506	503	538	525
Interest income recognized	2	2	5	3
Commercial Real Estate Loans [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	1,286		1,286		1,436
Unpaid Principal Balance	2,924		2,924		2,503
Valuation Allowance	92		92		124
Commitments to Lend Additional Funds	14		14		25
Average recorded investment	1,338	1,517	1,431	1,499
Interest income recognized	10	2	17	4
Residential Mortgage [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	2,671		2,671		2,652
Unpaid Principal Balance	3,299		3,299		3,193
Valuation Allowance	447		447		482
Commitments to Lend Additional Funds	1		1		2
Average recorded investment	2,687	2,541	2,663	2,524
Interest income recognized	30	25	56	50
Credit Card [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	526		526		584
Unpaid Principal Balance	526		526		584
Valuation Allowance	196		196		219
Average recorded investment	543	462	546	461
Interest income recognized	8	3	16	6
Other Retail [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	300		300		188
Unpaid Principal Balance	303		303		197
Valuation Allowance	61		61		57
Commitments to Lend Additional Funds	6		6
Average recorded investment	244	159	212	158
Interest income recognized	2	1	4	2
Total loans, excluding GNMA and covered loans [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	5,226		5,226		5,517
Unpaid Principal Balance	8,570		8,570		7,914
Valuation Allowance	851		851		944
Commitments to Lend Additional Funds	95		95		95
Average recorded investment	5,318	5,182	5,390	5,167
Interest income recognized	52	33	98	65
Loans purchased from GNMA [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	1,352		1,352		1,265
Unpaid Principal Balance	1,352		1,352		1,265
Valuation Allowance	39		39		18
Average recorded investment	1,320	439	1,299	301
Interest income recognized	16	5	31	9
Covered Financing Receivable [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	945		945		1,170
Unpaid Principal Balance	2,616		2,616		1,642
Valuation Allowance	36		36		43
Commitments to Lend Additional Funds	11		11		49
Average recorded investment	1,065	1,164	1,121	1,181
Interest income recognized	$ 11	$ 13	$ 13	$ 27