Loans TDR Modifications (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014 contracts		Jun. 30, 2013 contracts		Jun. 30, 2014 contracts		Jun. 30, 2013 contracts
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	1,732	[1]	2,544	[1]	3,455	[1]	4,869	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	$ 4	[1],[2]	$ 18	[1],[3]	$ 4	[1],[3]	$ 18	[1],[4]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	46	[1],[5]	61	[1],[4]	93	[1],[5]	123	[1],[4]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	57	[1]	118	[1]	114	[1]	208	[1]
Financing Receivable, Amount Restructured During Period	107	[1]	197	[1]	211	[1]	349	[1]
Consumer Indirect [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	712	[1]	831	[1]	1,551	[1]	1,734	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	14	[1]	16	[1]	30	[1]	33	[1]
Financing Receivable, Amount Restructured During Period	14	[1]	16	[1]	30	[1]	33	[1]
Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	27	[1]	29	[1]	43	[1]	96	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0		18	[1],[3]	0		18	[1],[3]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		0		0		2	[1],[4]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	12	[1]	15	[1]	14	[1]	49	[1]
Financing Receivable, Amount Restructured During Period	12	[1]	33	[1]	14	[1]	69	[1]
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	2	[1]	1	[1]	4	[1]	5	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	3	[1],[2]	0		3	[1],[2]	0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		0		0		4	[1],[4]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		0		3	[1]	1	[1]
Financing Receivable, Amount Restructured During Period	3	[1]	0		6	[1]	5	[1]
Residential Nonguaranteed [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	365	[1]	637	[1]	678	[1]	913	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	1	[1],[2]	0		1	[1],[2]	0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	43	[1],[5]	36	[1],[4]	86	[1],[5]	61	[1],[4]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	11	[1]	53	[1]	28	[1]	70	[1]
Financing Receivable, Amount Restructured During Period	55	[1]	89	[1]	115	[1]	131	[1]
Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	471	[1]	755	[1]	904	[1]	1,438	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	2	[1],[5]	17	[1],[4]	5	[1],[5]	36	[1],[4]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	20	[1]	31	[1]	38	[1]	48	[1]
Financing Receivable, Amount Restructured During Period	22	[1]	48	[1]	43	[1]	84	[1]
Residential Construction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	4	[1]	104	[1]	10	[1]	217	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	1	[1],[5]	7	[1],[4]	1	[1],[5]	18	[1],[4]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		2	[1]	0		4	[1]
Financing Receivable, Amount Restructured During Period	1	[1]	9	[1]	1	[1]	22	[1]
Consumer Other Direct [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	21	[1]	32	[1]	38	[1]	80	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		1	[1]	1	[1]	3	[1]
Financing Receivable, Amount Restructured During Period	0		1	[1]	1	[1]	3	[1]
Consumer Credit Card Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	130	[1]	155	[1]	227	[1]	386	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		1	[1],[4]	1	[1],[5]	2	[1],[4]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period	$ 0		$ 1	[1]	$ 1	[1]	$ 2	[1]

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

[2] Restructured loans which had forgiveness of amounts contractually due under the terms of the loan typically have had multiple concessions including rate modifications and/or term extensions. The total amount of charge-offs associated with principal forgiveness during both the three and six months ended June 30, 2014 was immaterial.

[3] Restructured loans which had forgiveness of amounts contractually due under the terms of the loan typically have had multiple concessions including rate modifications and/or term extensions. The total amount of charge-offs associated with principal forgiveness during both the three and six months ended June 30, 2013, was $2 million.

[4] 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 and six months ended June 30, 2013.

[5] 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 and six months ended June 30, 2014.