Loans and Allowance for Credit Losses (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	$ 7,881		$ 7,952
Unpaid Principal Balance	10,618		10,821
Valuation Allowance	964		1,005
Commitments to Lend Additional Funds	91		144
Average recorded investment	7,914	6,511
Interest income recognized	63	50
Commercial Loan [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	568		657
Unpaid Principal Balance	1,400		1,437
Valuation Allowance	54		62
Commitments to Lend Additional Funds	57		68
Average recorded investment	569	547
Interest income recognized	3	1
Commercial Real Estate Loans [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	1,389		1,436
Unpaid Principal Balance	2,350		2,503
Valuation Allowance	105		124
Commitments to Lend Additional Funds	9		25
Average recorded investment	1,524	1,481
Interest income recognized	7	2
Residential Mortgage [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	2,703		2,652
Unpaid Principal Balance	3,290		3,193
Valuation Allowance	487		482
Commitments to Lend Additional Funds	1		2
Average recorded investment	2,638	2,507
Interest income recognized	26	25
Credit Card [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	560		584
Unpaid Principal Balance	560		584
Valuation Allowance	208		219
Average recorded investment	548	459
Interest income recognized	8	3
Other Retail [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	188		188
Unpaid Principal Balance	197		197
Valuation Allowance	56		57
Average recorded investment	180	157
Interest income recognized	2	1
Total loans, excluding GNMA and covered loans [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	5,408		5,517
Unpaid Principal Balance	7,797		7,914
Valuation Allowance	910		944
Commitments to Lend Additional Funds	67		95
Average recorded investment	5,459	5,151
Interest income recognized	46	32
Loans purchased from GNMA [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	1,288		1,265
Unpaid Principal Balance	1,288		1,265
Valuation Allowance	20		18
Average recorded investment	1,277	162
Interest income recognized	15	4
Covered Financing Receivable [Member]
Additional detail of impaired loans by portfolio type
Period-end Recorded Investment	1,185		1,170
Unpaid Principal Balance	1,533		1,642
Valuation Allowance	34		43
Commitments to Lend Additional Funds	24		49
Average recorded investment	1,178	1,198
Interest income recognized	$ 2	$ 14