Allowance for Credit Losses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Allowance for loan losses:
Allowance for loan losses at January 1	$ 27,609	$ 32,266
Net charge-offs	2,853	4,344
Gross (recoveries)	(466)	(624)
Net charge-offs	2,387	3,720
Provision for loan losses	646	1,196
Other	3	8
Ending balance at March 31	25,871	29,750
Allowance for loan losses by impairment methodology:
Asset-specific, allowance	3,610	5,916
Formula-based	16,550	18,893
Purchased Credit Impaired	5,711	4,941
Total allowance for loan losses	25,871	29,750
Loans by impairment methodology:
Asset-specific	18,641	20,988
Formula-based	630,174	583,628
Purchased credit-impaired	64,083	70,821
Retained loans	712,898	675,437	718,997
Impaired collateral-dependent loans:
Loans measured at fair value of collateral less cost to sell	1,639	2,085
Allowance for lending-related commitments
Allowance for lending-related commitments, Beginning balance at January 1	673	717
Provision For Lending Related Commitments	80	(27)
Other	(3)	(2)
Valuation allowances, Ending balance at March 31	750	688
Allowance for lending-related commitments by impairment methodology
Asset-specific	187	184
Formula-based	563	504
Total allowances for lending-related commitments	750	688
Lending-related commitments by impairment methodology
Asset-specific	756	895
Formula-based	996,747	985,039
Total lending related commitments	997,503	985,934	975,662
Wholesale
Allowance for loan losses:
Allowance for loan losses at January 1	4,316	4,761
Net charge-offs	92	253
Gross (recoveries)	(87)	(88)
Net charge-offs	5	165
Provision for loan losses	8	(359)
Other	4	(3)
Ending balance at March 31	4,323	4,234
Allowance for loan losses by impairment methodology:
Asset-specific, allowance	448	1,030
Formula-based	3,875	3,204
Purchased Credit Impaired	0	0
Total allowance for loan losses	4,323	4,234
Loans by impairment methodology:
Asset-specific	2,058	4,498
Formula-based	281,573	225,094
Purchased credit-impaired	22	56
Retained loans	283,653	229,648
Impaired collateral-dependent loans:
Loans measured at fair value of collateral less cost to sell	790	1,221
Consumer Excluding Credit Card
Allowance for loan losses:
Allowance for loan losses at January 1	16,294	16,471
Net charge-offs	1,134	1,460
Gross (recoveries)	(138)	(131)
Net charge-offs	996	1,329
Provision for loan losses	2	1,329
Other	(3)	4
Ending balance at March 31	15,297	16,475
Allowance for loan losses by impairment methodology:
Asset-specific, allowance	760	1,067
Formula-based	8,826	10,467
Purchased Credit Impaired	5,711	4,941
Total allowance for loan losses	15,297	16,475
Loans by impairment methodology:
Asset-specific	10,059	7,254
Formula-based	230,650	242,979
Purchased credit-impaired	64,061	70,765
Retained loans	304,770	320,998
Impaired collateral-dependent loans:
Loans measured at fair value of collateral less cost to sell	849	864
Credit Card
Allowance for loan losses:
Allowance for loan losses at January 1	6,999	11,034
Net charge-offs	1,627	2,631
Gross (recoveries)	(241)	(405)
Net charge-offs	1,386	2,226
Provision for loan losses	636	226
Other	2	7
Ending balance at March 31	6,251	9,041
Allowance for loan losses by impairment methodology:
Asset-specific, allowance	2,402	3,819
Formula-based	3,849	5,222
Purchased Credit Impaired	0	0
Total allowance for loan losses	6,251	9,041
Loans by impairment methodology:
Asset-specific	6,524	9,236
Formula-based	117,951	115,555
Purchased credit-impaired	0	0
Retained loans	124,475	124,791
Impaired collateral-dependent loans:
Loans measured at fair value of collateral less cost to sell	0	0
Impaired collateral dependent loans [Member]
Allowance for loan losses:
Net charge-offs	53	52
Impaired collateral dependent loans [Member] | Wholesale
Allowance for loan losses:
Net charge-offs	24	27
Impaired collateral dependent loans [Member] | Consumer Excluding Credit Card
Allowance for loan losses:
Net charge-offs	29	25
Impaired collateral dependent loans [Member] | Credit Card
Allowance for loan losses:
Net charge-offs	0	0
Wholesale
Allowance for lending-related commitments
Allowance for lending-related commitments, Beginning balance at January 1	666	711
Provision For Lending Related Commitments	81	(27)
Other	(4)	(2)
Valuation allowances, Ending balance at March 31	743	682
Allowance for lending-related commitments by impairment methodology
Asset-specific	187	184
Formula-based	556	498
Total allowances for lending-related commitments	743	682
Lending-related commitments by impairment methodology
Asset-specific	756	895
Formula-based	400,308	354,666
Total lending related commitments	401,064	355,561
Consumer Excluding Credit Card
Allowance for lending-related commitments
Allowance for lending-related commitments, Beginning balance at January 1	7	6
Provision For Lending Related Commitments	(1)	0
Other	1	0
Valuation allowances, Ending balance at March 31	7	6
Allowance for lending-related commitments by impairment methodology
Asset-specific	0	0
Formula-based	7	6
Total allowances for lending-related commitments	7	6
Lending-related commitments by impairment methodology
Asset-specific	0	0
Formula-based	63,121	64,560
Total lending related commitments	63,121	64,560
Credit Card
Allowance for lending-related commitments
Allowance for lending-related commitments, Beginning balance at January 1	0	0
Provision For Lending Related Commitments	0	0
Other	0	0
Valuation allowances, Ending balance at March 31	0	0
Allowance for lending-related commitments by impairment methodology
Asset-specific	0	0
Formula-based	0	0
Total allowances for lending-related commitments	0	0
Lending-related commitments by impairment methodology
Asset-specific	0	0
Formula-based	533,318	565,813
Total lending related commitments	$ 533,318	$ 565,813