Loans - Consumer Loans excluding Credit Card, Delinquency (Details 6a) (USD $)	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	$ 712,898,000,000	$ 718,997,000,000	$ 675,437,000,000
Prime Mortgage Loans Repurchased From Government National Mortgage Association Pools	15,800,000,000	15,600,000,000
Mortgage Loans Insured By US Government Agencies Excluded From The Percentage Of Thirty Or More Days Past Due To Retained Loans	12,700,000,000	12,600,000,000
Residential real estate, excluding PCI [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	160,788,000,000	163,660,000,000
Percentage of Loans 30 Plus Days Past Due To Total Retained Loans	4.61%	4.97%
Residential real estate, excluding PCI [Member] | Current and less than 30 days past due and still accruing [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	140,645,000,000	142,965,000,000
Residential real estate, excluding PCI [Member] | 30 - 149 Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	5,149,000,000	5,972,000,000
Residential real estate, excluding PCI [Member] | Nonaccrual [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	7,593,000,000	6,530,000,000
Residential real estate, excluding PCI [Member] | 150 or More Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	14,994,000,000	14,723,000,000
Residential real estate, excluding PCI [Member] | Past Due And Still Accruing 90 Days Or More Member
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	0	0
Residential real estate, excluding PCI [Member] | Past Due 90 Days Or More And Government Guaranteed [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	11,841,000,000	11,516,000,000
Home Equity Senior Lien [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	21,202,000,000	21,765,000,000
Percentage of Loans 30 Plus Days Past Due To Total Retained Loans	3.44%	3.55%
Home Equity Senior Lien [Member] | Current and less than 30 days past due and still accruing [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	20,472,000,000	20,992,000,000
Home Equity Senior Lien [Member] | 30 - 149 Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	352,000,000	405,000,000
Home Equity Senior Lien [Member] | Nonaccrual [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	489,000,000	495,000,000
Home Equity Senior Lien [Member] | 150 or More Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	378,000,000	368,000,000
Home Equity Senior Lien [Member] | Past Due And Still Accruing 90 Days Or More Member
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	0	0
Home Equity Senior Lien [Member] | Past Due 90 Days Or More And Government Guaranteed [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	0	0
Home Equity Junior Lien [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	54,005,000,000	56,035,000,000
Percentage of Loans 30 Plus Days Past Due To Total Retained Loans	2.42%	2.68%
Home Equity Junior Lien [Member] | Current and less than 30 days past due and still accruing [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	52,697,000,000	54,533,000,000
Home Equity Junior Lien [Member] | 30 - 149 Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	1,077,000,000	1,272,000,000
Home Equity Junior Lien [Member] | Nonaccrual [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	2,277,000,000	792,000,000
Home Equity Junior Lien [Member] | 150 or More Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	231,000,000	230,000,000
Home Equity Junior Lien [Member] | Past Due And Still Accruing 90 Days Or More Member
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	0	0
Home Equity Junior Lien [Member] | Past Due 90 Days Or More And Government Guaranteed [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	0	0
Prime Mortgages, including option ARMs [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	76,292,000,000	76,196,000,000
Percentage of Loans 30 Plus Days Past Due To Total Retained Loans	4.59%	4.96%
Prime Mortgages, including option ARMs [Member] | Current and less than 30 days past due and still accruing [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	60,051,000,000	59,855,000,000
Prime Mortgages, including option ARMs [Member] | 30 - 149 Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	2,980,000,000	3,475,000,000
Prime Mortgages, including option ARMs [Member] | Nonaccrual [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	3,258,000,000	3,462,000,000
Prime Mortgages, including option ARMs [Member] | 150 or More Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	13,261,000,000	12,866,000,000
Prime Mortgages, including option ARMs [Member] | Past Due And Still Accruing 90 Days Or More Member
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	0	0
Prime Mortgages, including option ARMs [Member] | Past Due 90 Days Or More And Government Guaranteed [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	11,841,000,000	11,516,000,000
Subprime Mortgage [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	9,289,000,000	9,664,000,000
Percentage of Loans 30 Plus Days Past Due To Total Retained Loans	20.07%	21.51%
Subprime Mortgage [Member] | Current and less than 30 days past due and still accruing [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	7,425,000,000	7,585,000,000
Subprime Mortgage [Member] | 30 - 149 Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	740,000,000	820,000,000
Subprime Mortgage [Member] | Nonaccrual [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	1,569,000,000	1,781,000,000
Subprime Mortgage [Member] | 150 or More Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	1,124,000,000	1,259,000,000
Subprime Mortgage [Member] | Past Due And Still Accruing 90 Days Or More Member
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	0	0
Subprime Mortgage [Member] | Past Due 90 Days Or More And Government Guaranteed [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	0	0
Mortgage Loans Insured by US Government Agencies [Member] | Current and less than 30 days past due and still accruing [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	3,100,000,000	3,000,000,000
Mortgage Loans Insured by US Government Agencies [Member] | 30 - 149 Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	2,000,000,000	2,300,000,000
Mortgage Loans Insured by US Government Agencies [Member] | 150 or More Days Past Due [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	10,700,000,000	10,300,000,000
Past Due 90 Days Or More And Government Guaranteed [Member] | Nonaccrual [Member]
Consumer Loans Excluding Credit Card Portfolio Segment, by Class, by Delinquency [Line Items]
Retained loans	$ 7,300,000,000	$ 7,000,000,000