Loans TDR Modifications (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 contracts		Mar. 31, 2013 contracts
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	1,723	[1]	2,325	[1]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	$ 47	[1],[2]	$ 62	[1],[3]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	57	[1]	89	[1]
Financing Receivable, Amount Restructured During Period	104	[1]	151	[1]
Consumer Indirect [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	839	[1]	903	[1]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		0
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	16	[1]	17	[1]
Financing Receivable, Amount Restructured During Period	16	[1]	17	[1]
Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	16	[1]	67	[1]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		2	[1],[3]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	2	[1]	35	[1]
Financing Receivable, Amount Restructured During Period	2	[1]	37	[1]
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	2	[1]	4	[1]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		3	[1],[3]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	3	[1]	0
Financing Receivable, Amount Restructured During Period	3	[1]	3	[1]
Residential Nonguaranteed [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	313	[1]	276	[1]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	43	[1],[2]	25	[1],[3]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	18	[1]	17	[1]
Financing Receivable, Amount Restructured During Period	61	[1]	42	[1]
Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	433	[1]	683	[1]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	3	[1],[2]	19	[1],[3]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	18	[1]	18	[1]
Financing Receivable, Amount Restructured During Period	21	[1]	37	[1]
Residential Construction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	6	[1]	113	[1]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		12	[1],[3]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		1	[1]
Financing Receivable, Amount Restructured During Period	0		13	[1]
Consumer Other Direct [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	17	[1]	48	[1]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		0
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		1	[1]
Financing Receivable, Amount Restructured During Period	0		1	[1]
Consumer Credit Card Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	97	[1]	231	[1]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	1	[1],[2]	1	[1],[3]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		0
Financing Receivable, Amount Restructured During Period	$ 1	[1]	$ 1	[1]

[1] Includes loans modified under the terms of a TDR that were charged-off during the period.

[2] Restructured loans which had a modification of the loan's contractual interest rate may also have had an extension of the loan's contractual maturity date and/or other concessions. The financial effect of modifying the interest rate on the loans modified as a TDR was immaterial to the financial statements during the three months ended March 31, 2014.

[3] Restructured loans which had a modification of the loan's contractual interest rate may also have had an extension of the loan's contractual maturity date and/or other concessions. The financial effect of modifying the interest rate on the loans modified as a TDR was immaterial to the financial statements during the three months ended March 31, 2013.