Loans - Consumer Loans excluding Credit Card, Geographic Region (Details 6c) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	$ 712,898	$ 718,997	$ 675,437
Residential real estate, excluding PCI [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	160,788	163,660
Residential real estate, excluding PCI [Member] | California [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	34,700	35,409
Residential real estate, excluding PCI [Member] | New York [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	25,244	25,419
Residential real estate, excluding PCI [Member] | Florida [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	9,450	9,769
Residential real estate, excluding PCI [Member] | Illinois [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	9,370	9,593
Residential real estate, excluding PCI [Member] | Texas [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	7,817	8,037
Residential real estate, excluding PCI [Member] | New Jersey [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	6,295	6,428
Residential real estate, excluding PCI [Member] | Arizona [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	5,109	5,284
Residential real estate, excluding PCI [Member] | Washington [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	4,585	4,696
Residential real estate, excluding PCI [Member] | Ohio [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	3,621	3,750
Residential real estate, excluding PCI [Member] | Michigan [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	3,491	3,599
Residential real estate, excluding PCI [Member] | All Other States [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	51,106	51,676
Subprime Mortgage [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	9,289	9,664
Subprime Mortgage [Member] | California [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,409	1,463
Subprime Mortgage [Member] | New York [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,180	1,217
Subprime Mortgage [Member] | Florida [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,142	1,206
Subprime Mortgage [Member] | Illinois [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	372	391
Subprime Mortgage [Member] | Texas [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	290	300
Subprime Mortgage [Member] | New Jersey [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	441	461
Subprime Mortgage [Member] | Arizona [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	190	199
Subprime Mortgage [Member] | Washington [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	203	209
Subprime Mortgage [Member] | Ohio [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	225	234
Subprime Mortgage [Member] | Michigan [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	236	246
Subprime Mortgage [Member] | All Other States [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	3,601	3,738
Prime Mortgages, including option ARMs [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	76,292	76,196
Prime Mortgages, including option ARMs [Member] | California [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	17,887	18,029
Prime Mortgages, including option ARMs [Member] | New York [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	10,457	10,200
Prime Mortgages, including option ARMs [Member] | Florida [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	4,448	4,565
Prime Mortgages, including option ARMs [Member] | Illinois [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	3,889	3,922
Prime Mortgages, including option ARMs [Member] | Texas [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	2,862	2,851
Prime Mortgages, including option ARMs [Member] | New Jersey [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	2,045	2,042
Prime Mortgages, including option ARMs [Member] | Arizona [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,164	1,194
Prime Mortgages, including option ARMs [Member] | Washington [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,852	1,878
Prime Mortgages, including option ARMs [Member] | Ohio [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	432	441
Prime Mortgages, including option ARMs [Member] | Michigan [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	890	909
Prime Mortgages, including option ARMs [Member] | All Other States [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	30,366	30,165
Home Equity Senior Lien [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	21,202	21,765
Home Equity Senior Lien [Member] | California [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	3,002	3,066
Home Equity Senior Lien [Member] | New York [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	2,972	3,023
Home Equity Senior Lien [Member] | Florida [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	967	992
Home Equity Senior Lien [Member] | Illinois [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,460	1,495
Home Equity Senior Lien [Member] | Texas [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	2,901	3,027
Home Equity Senior Lien [Member] | New Jersey [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	677	687
Home Equity Senior Lien [Member] | Arizona [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,303	1,339
Home Equity Senior Lien [Member] | Washington [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	702	714
Home Equity Senior Lien [Member] | Ohio [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,694	1,747
Home Equity Senior Lien [Member] | Michigan [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,016	1,044
Home Equity Senior Lien [Member] | All Other States [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	4,508	4,631
Home Equity Junior Lien [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	54,005	56,035
Home Equity Junior Lien [Member] | California [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	12,402	12,851
Home Equity Junior Lien [Member] | New York [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	10,635	10,979
Home Equity Junior Lien [Member] | Florida [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	2,893	3,006
Home Equity Junior Lien [Member] | Illinois [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	3,649	3,785
Home Equity Junior Lien [Member] | Texas [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,764	1,859
Home Equity Junior Lien [Member] | New Jersey [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	3,132	3,238
Home Equity Junior Lien [Member] | Arizona [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	2,452	2,552
Home Equity Junior Lien [Member] | Washington [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,828	1,895
Home Equity Junior Lien [Member] | Ohio [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,270	1,328
Home Equity Junior Lien [Member] | Michigan [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	1,349	1,400
Home Equity Junior Lien [Member] | All Other States [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Geographic Region [Line Items]
Retained loans	$ 12,631	$ 13,142