Loans TDR Modifications (Details) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015 USD ($) contracts		Sep. 30, 2014 USD ($) contracts		Sep. 30, 2015 USD ($) contracts		Sep. 30, 2014 USD ($) contracts
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts | contracts	1,396	[1]	1,575	[2]	4,674	[1]	5,030	[2]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	$ 3	[1],[3]	$ 2	[2],[4]	$ 10	[1],[3]	$ 11	[2],[4]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	40	[1]	28	[2]	118	[1]	114	[2]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	44	[1]	50	[2]	127	[1]	166	[2]
Financing Receivable, Amount Restructured During Period	$ 87	[1]	$ 80	[2]	$ 255	[1]	$ 291	[2]
Commercial and Industrial Sector [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts | contracts	18	[1]	23	[2]	63	[1]	66	[2]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	$ 0		$ 0		$ 0		$ 0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	0		0		1	[1]	0
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		8	[2]	5	[1]	22	[2]
Financing Receivable, Amount Restructured During Period	$ 0		$ 8	[2]	$ 6	[1]	$ 22	[2]
Credit Card Receivable [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts | contracts	157	[1]	123	[2]	529	[1]	350	[2]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	$ 0		$ 0		$ 0		$ 0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	1	[1]	1	[2]	2	[1]	2	[2]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period	$ 1	[1]	$ 1	[2]	$ 2	[1]	$ 2	[2]
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts | contracts					1	[1]	4	[2]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted					$ 0		$ 3	[2],[4]
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		3	[2]
Financing Receivable, Amount Restructured During Period					$ 0		$ 6	[2]
Residential Nonguaranteed [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts | contracts	175	[1]	266	[2]	632	[1]	944	[2]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	$ 3	[1],[3]	$ 2	[2],[4]	$ 10	[1],[3]	$ 8	[2],[4]
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	32	[1]	26	[2]	95	[1]	105	[2]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	10	[1]	8	[2]	20	[1]	38	[2]
Financing Receivable, Amount Restructured During Period	$ 45	[1]	$ 36	[2]	$ 125	[1]	$ 151	[2]
Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts | contracts	419	[1]	503	[2]	1,386	[1]	1,407	[2]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	$ 0		$ 0		$ 0		$ 0
Financing Receivable, Amount Restructured During Period, Rate Modifications Granted	7	[1]	1	[2]	20	[1]	6	[2]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	21	[1]	22	[2]	62	[1]	59	[2]
Financing Receivable, Amount Restructured During Period	$ 28	[1]	$ 23	[2]	$ 82	[1]	$ 65	[2]
Residential Construction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts | contracts	6	[1]	1	[2]	17	[1]	11	[2]
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		1	[2]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0		0		0		0
Financing Receivable, Amount Restructured During Period	$ 0		$ 0		$ 0		$ 1	[2]
Consumer Other Direct [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts | contracts	10	[1]	21	[2]	47	[1]	59	[2]
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		0		1	[1]	1	[2]
Financing Receivable, Amount Restructured During Period	$ 0		$ 0		$ 1	[1]	$ 1	[2]
Consumer Indirect [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts | contracts	611	[1]	638	[2]	1,999	[1]	2,189	[2]
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	13	[1]	12	[2]	39	[1]	43	[2]
Financing Receivable, Amount Restructured During Period	$ 13	[1]	$ 12	[2]	$ 39	[1]	$ 43	[2]

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

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

[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 nine months ended September 30, 2015 was immaterial.

[4] 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 nine months ended September 30, 2014 was immaterial.