Loans - Residential RealEstate - PCI Loans, Delinquency (Details 8a) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Residential Real Estate PCI Loans by Delinquency [Line Items]
Estimated weighted-average life of the portfolio over which net spread will be earned on a declining loan balance	7.5
Purchased Credit Impaired [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Value	$ 65,546	$ 72,763
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	5,711	4,941
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	74,492	86,073
Percentage Of Loans Thirty Plus Days Past Due To Total Retained Loans	23.30%	28.20%
Purchased Credit Impaired [Member] | Current and less than 30 days past due and still accruing [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	57,137	61,802
Purchased Credit Impaired [Member] | Days Past Due, 30 to 149 [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	4,291	6,051
Purchased Credit Impaired [Member] | Days Past Due 150 Or More [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	13,064	18,220
PCI Option ARMs [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Value	22,693	25,584
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	1,494	1,494
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	26,139	30,791
Percentage Of Loans Thirty Plus Days Past Due To Total Retained Loans	31.45%	39.36%
PCI Option ARMs [Member] | Current and less than 30 days past due and still accruing [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	17,919	18,672
PCI Option ARMs [Member] | Days Past Due, 30 to 149 [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,467	2,215
PCI Option ARMs [Member] | Days Past Due 150 Or More [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	6,753	9,904
PCI Home Equity [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Value	22,697	24,459
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	1,908	1,583
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	25,064	28,312
Percentage Of Loans Thirty Plus Days Past Due To Total Retained Loans	9.50%	8.93%
PCI Home Equity [Member] | Current and less than 30 days past due and still accruing [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	22,682	25,783
PCI Home Equity [Member] | Days Past Due, 30 to 149 [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,130	1,348
PCI Home Equity [Member] | Days Past Due 150 Or More [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,252	1,181
PCI Prime Mortgage [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Value	15,180	17,322
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	1,929	1,766
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	16,060	18,928
Percentage Of Loans Thirty Plus Days Past Due To Total Retained Loans	24.36%	31.13%
PCI Prime Mortgage [Member] | Current and less than 30 days past due and still accruing [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	12,148	13,035
PCI Prime Mortgage [Member] | Days Past Due, 30 to 149 [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	912	1,468
PCI Prime Mortgage [Member] | Days Past Due 150 Or More [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	3,000	4,425
PCI Subprime Mortgage [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Value	4,976	5,398
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	380	98
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	7,229	8,042
Percentage Of Loans Thirty Plus Days Past Due To Total Retained Loans	39.30%	46.38%
PCI Subprime Mortgage [Member] | Current and less than 30 days past due and still accruing [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	4,388	4,312
PCI Subprime Mortgage [Member] | Days Past Due, 30 to 149 [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	782	1,020
PCI Subprime Mortgage [Member] | Days Past Due 150 Or More [Member]
Residential Real Estate PCI Loans by Delinquency [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	$ 2,059	$ 2,710