Allowance for Credit Losses (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Loan and Lease Losses [Roll Forward]
Provision for credit losses	$ 225	$ 3,385	$ 7,574
Loans by Impairment Methodology [Abstract]
Asset-specific	17,745	20,175	19,655
Formula-based	653,371	646,904	633,775
Purchased credit-impaired	53,061	59,756	65,567
Retained loans	724,177	726,835	718,997
Lending-related commitments by impairment methodology
Asset-specific	206	355	865
Formula-based	1,031,466	1,027,633	974,797
Total lending-related commitments	1,031,672	1,027,988	975,662
Impaired collateral-dependent loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for Loan and Lease Losses Write-offs, Net	272	1,050	(238)
Impaired Collateral Dependent Loans [Abstract]
Loans measured at fair value of collateral less cost to sell	3,467	3,717	1,663
Residential Real Estate, Excluding Purchased Credit-Impaired [Member] | Regulatory Guidance Regarding Chapter 7 Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Gross charge-offs		747
Auto [Member] | Regulatory Guidance Regarding Chapter 7 Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Gross charge-offs		53
Allowance for loan losses by impairment methodology [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning balance	21,936	27,609	32,266
Gross charge-offs	7,467	10,906	14,503
Gross (recoveries)	(1,665)	(1,843)	(2,266)
Allowance for Loan and Lease Losses Write-offs, Net	5,802	9,063	12,237
Provision for credit losses	188	3,387	7,612
Other	(5)	3	(32)
Allowance for credit losses, ending balance	16,264	21,936	27,609
Allowance For Lending Related Commitments, by Impairment Methodology [Abstract]
Asset-specific, allowance	1,753	2,729	4,071
Formula-based	10,353	13,496	17,827
Purchased Credit Impaired	4,158	5,711	5,711
Total allowance for loan losses	16,264	21,936	27,609
Allowance for loan losses by impairment methodology [Member] | Purchased Credit-Impaired [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Gross charge-offs	53	0	0
Allowance for lending-related commitments [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning balance	668	673	717
Provision for credit losses	37	2	38
Other	0	(3)	(6)
Allowance for credit losses, ending balance	705	668	673
Allowance For Lending Related Commitments, by Impairment Methodology [Abstract]
Allowance for Lending-Related Commitments, Evaluated at Asset-Specific Impairment Methodology	60	97	150
Allowance for Lending-Related Commitments, Evaluated at Formula-Based Impairment Methodology	645	571	523
Total allowance for loan losses	705	668	673
Consumer, excluding credit card [Member]
Loans by Impairment Methodology [Abstract]
Asset-specific	13,785	13,938	9,892
Formula-based	221,609	218,945	232,989
Purchased credit-impaired	53,055	59,737	65,546
Retained loans	288,449	292,620	308,427
Lending-related commitments by impairment methodology
Asset-specific	0	0	0
Formula-based	56,057	60,156	62,307
Total lending-related commitments	56,057	60,156	62,307
Consumer, excluding credit card [Member] | Purchased Credit-Impaired [Member]
Loans by Impairment Methodology [Abstract]
Retained loans	53,055	59,737
Consumer, excluding credit card [Member] | Impaired collateral-dependent loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for Loan and Lease Losses Write-offs, Net	235	973	(110)
Impaired Collateral Dependent Loans [Abstract]
Loans measured at fair value of collateral less cost to sell	3,105	3,272	830
Consumer, excluding credit card [Member] | Residential Real Estate, Excluding Purchased Credit-Impaired [Member]
Loans by Impairment Methodology [Abstract]
Retained loans	152,129	151,896
Consumer, excluding credit card [Member] | Auto [Member]
Loans by Impairment Methodology [Abstract]
Retained loans	52,757	49,913
Consumer, excluding credit card [Member] | Allowance for loan losses by impairment methodology [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning balance	12,292	16,294	16,471
Gross charge-offs	2,754	4,805	5,419
Gross (recoveries)	(847)	(508)	(547)
Allowance for Loan and Lease Losses Write-offs, Net	1,907	4,297	4,872
Provision for credit losses	(1,872)	302	4,670
Other	(4)	(7)	25
Allowance for credit losses, ending balance	8,456	12,292	16,294
Allowance For Lending Related Commitments, by Impairment Methodology [Abstract]
Asset-specific, allowance	601	729	828
Formula-based	3,697	5,852	9,755
Purchased Credit Impaired	4,158	5,711	5,711
Total allowance for loan losses	8,456	12,292	16,294
Consumer, excluding credit card [Member] | Allowance for loan losses by impairment methodology [Member] | Purchased Credit-Impaired [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Gross charge-offs	53	0	0
Consumer, excluding credit card [Member] | Allowance for lending-related commitments [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning balance	7	7	6
Provision for credit losses	1	0	(2)
Other	0	0	(1)
Allowance for credit losses, ending balance	8	7	7
Allowance For Lending Related Commitments, by Impairment Methodology [Abstract]
Allowance for Lending-Related Commitments, Evaluated at Asset-Specific Impairment Methodology	0	0	0
Allowance for Lending-Related Commitments, Evaluated at Formula-Based Impairment Methodology	8	7	7
Total allowance for loan losses	8	7	7
Credit card [Member]
Loans by Impairment Methodology [Abstract]
Asset-specific	3,115	4,762	7,214
Formula-based	124,350	123,231	124,961
Purchased credit-impaired	0	0	0
Retained loans	127,465	127,993	132,175
Lending-related commitments by impairment methodology
Asset-specific	0	0	0
Formula-based	529,383	533,018	530,616
Total lending-related commitments	529,383	533,018	530,616
Credit card [Member] | Impaired collateral-dependent loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for Loan and Lease Losses Write-offs, Net	0	0	0
Impaired Collateral Dependent Loans [Abstract]
Loans measured at fair value of collateral less cost to sell	0	0	0
Credit card [Member] | Allowance for loan losses by impairment methodology [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning balance	5,501	6,999	11,034
Gross charge-offs	4,472	5,755	8,168
Gross (recoveries)	(593)	(811)	(1,243)
Allowance for Loan and Lease Losses Write-offs, Net	3,879	4,944	6,925
Provision for credit losses	2,179	3,444	2,925
Other	(6)	2	(35)
Allowance for credit losses, ending balance	3,795	5,501	6,999
Allowance For Lending Related Commitments, by Impairment Methodology [Abstract]
Asset-specific, allowance	971	1,681	2,727
Formula-based	2,824	3,820	4,272
Purchased Credit Impaired	0	0	0
Total allowance for loan losses	3,795	5,501	6,999
Credit card [Member] | Allowance for loan losses by impairment methodology [Member] | Purchased Credit-Impaired [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Gross charge-offs	0	0	0
Credit card [Member] | Allowance for lending-related commitments [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning balance	0	0	0
Provision for credit losses	0	0	0
Other	0	0	0
Allowance for credit losses, ending balance	0	0	0
Allowance For Lending Related Commitments, by Impairment Methodology [Abstract]
Allowance for Lending-Related Commitments, Evaluated at Asset-Specific Impairment Methodology	0	0	0
Allowance for Lending-Related Commitments, Evaluated at Formula-Based Impairment Methodology	0	0	0
Total allowance for loan losses	0	0	0
Wholesale [Member]
Loans by Impairment Methodology [Abstract]
Asset-specific	845	1,475	2,549
Formula-based	307,412	304,728	275,825
Purchased credit-impaired	6	19	21
Retained loans	308,263	306,222	278,395
Lending-related commitments by impairment methodology
Asset-specific	206	355	865
Formula-based	446,026	434,459	381,874
Total lending-related commitments	446,232	434,814	382,739
Wholesale [Member] | Impaired collateral-dependent loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for Loan and Lease Losses Write-offs, Net	37	77	(128)
Impaired Collateral Dependent Loans [Abstract]
Loans measured at fair value of collateral less cost to sell	362	445	833
Wholesale [Member] | Allowance for loan losses by impairment methodology [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning balance	4,143	4,316	4,761
Gross charge-offs	241	346	916
Gross (recoveries)	(225)	(524)	(476)
Allowance for Loan and Lease Losses Write-offs, Net	16	(178)	440
Provision for credit losses	(119)	(359)	17
Other	5	8	(22)
Allowance for credit losses, ending balance	4,013	4,143	4,316
Allowance For Lending Related Commitments, by Impairment Methodology [Abstract]
Asset-specific, allowance	181	319	516
Formula-based	3,832	3,824	3,800
Purchased Credit Impaired	0	0	0
Total allowance for loan losses	4,013	4,143	4,316
Wholesale [Member] | Allowance for loan losses by impairment methodology [Member] | Purchased Credit-Impaired [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Gross charge-offs	0	0	0
Wholesale [Member] | Allowance for lending-related commitments [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit losses, beginning balance	661	666	711
Provision for credit losses	36	2	40
Other	0	(3)	(5)
Allowance for credit losses, ending balance	697	661	666
Allowance For Lending Related Commitments, by Impairment Methodology [Abstract]
Allowance for Lending-Related Commitments, Evaluated at Asset-Specific Impairment Methodology	60	97	150
Allowance for Lending-Related Commitments, Evaluated at Formula-Based Impairment Methodology	637	564	516
Total allowance for loan losses	$ 697	$ 661	$ 666