Loans Troubled Debt Restructurings (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 contracts		Dec. 31, 2011 contracts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	683	[1]	1,238	[2]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	$ 52	[1]	$ 204	[2]
Commercial and Industrial | Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	84	[1]	71	[2]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	5	[1]	14	[2]
Commercial Real Estate | Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	9	[1]	14	[2]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	5	[1]	22	[2]
Commercial Construction [Member] | Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	10	[1]	32	[2]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	7	[1]	28	[2]
Residential Nonguaranteed [Member] | Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	141	[1]	455	[2]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	20	[1]	108	[2]
Home Equity | Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	164	[1]	220	[2]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	11	[1]	22	[2]
Residential Construction | Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	24	[1]	33	[2]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	3	[1]	7	[2]
Consumer Other Direct | Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	4	[1]	10	[2]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	0	[1]	0	[2]
Consumer Indirect | Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	43	[1]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	0	[1]
Consumer Credit Card | Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	204	[1]	403	[2]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	$ 1	[1]	$ 3	[2]

[1] For the year ended December 31, 2012, this represents defaults on loans that were first modified between the periods January 1, 2011 and December 31, 2012, including loans modified under the terms of a TDR that were charged-off during the periods.

[2] For the year ended December 31, 2011, this represents defaults on loans that were first modified between the periods January 1, 2010 and December 31, 2011, including loans modified under the terms of a TDR that were charged-off during the periods.