Loans TDR Modifications (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012 contracts		Sep. 30, 2011 contracts		Sep. 30, 2012 contracts		Sep. 30, 2011 contracts
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	2,292	[1]	2,090	[1]	5,647	[1]	4,977	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	$ 10	[1],[2]	$ 11	[1],[3]	$ 24	[1],[2]	$ 87	[1],[3]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	49	[1],[4]	139	[1],[5]	169	[1],[4]	400	[1],[5]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	56	[1]	124	[1]	132	[1]	200	[1]
total modifications	115	[1]	274	[1]	325	[1]	687	[1]
PrincipalForgivenessRestructuringImpact	1		3		2		12
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	159	[6]	323	[7]	486	[6]	993	[7]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	6	[6]	54	[7]	43	[6]	173	[7]
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	87	[1]	208	[1]	270	[1]	391	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	4	[1],[2]	0	[1],[3]	4	[1],[2]	27	[1],[3]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	1	[1],[4]	21	[1],[5]	3	[1],[4]	43	[1],[5]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	6	[1]	30	[1]	21	[1]	39	[1]
total modifications	11	[1]	51	[1]	28	[1]	109	[1]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	38	[6]	23	[7]	63	[6]	43	[7]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	1	[6]	6	[7]	4	[6]	8	[7]
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	4	[1]	9	[1]	27	[1]	34	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	5	[1],[2]	2	[1],[3]	17	[1],[2]	24	[1],[3]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	0	[1],[4]	8	[1],[5]	7	[1],[4]	24	[1],[5]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0	[1]	6	[1]	2	[1]	21	[1]
total modifications	5	[1]	16	[1]	26	[1]	69	[1]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	0	[6]	5	[7]	4	[6]	11	[7]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	0	[6]	21	[7]	4	[6]	21	[7]
Commercial Portfolio Segment [Member] | Commercial Construction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	3	[1]	11	[1]	15	[1]	93	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	1	[1],[2]	9	[1],[3]	3	[1],[2]	36	[1],[3]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	0	[1],[4]	6	[1],[5]	0	[1],[4]	8	[1],[5]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	2	[1]	50	[1]	13	[1]	91	[1]
total modifications	3	[1]	65	[1]	16	[1]	135	[1]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	2	[6]	1	[7]	9	[6]	15	[7]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	0	[6]	0	[7]	6	[6]	24	[7]
Residential Portfolio Segment [Member] | Residential Nonguaranteed [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	279	[1]	304	[1]	703	[1]	832	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0	[1],[2]	0	[1],[3]	0	[1],[2]	0	[1],[3]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	20	[1],[4]	57	[1],[5]	61	[1],[4]	199	[1],[5]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	1	[1]	4	[1]	2	[1]	12	[1]
total modifications	21	[1]	61	[1]	63	[1]	211	[1]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	31	[6]	60	[7]	87	[6]	394	[7]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	2	[6]	19	[7]	16	[6]	95	[7]
Residential Portfolio Segment [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	431	[1]	569	[1]	1,272	[1]	1,312	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0	[1],[2]	0	[1],[3]	0	[1],[2]	0	[1],[3]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	26	[1],[4]	38	[1],[5]	90	[1],[4]	100	[1],[5]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	4	[1]	4	[1]	7	[1]	4	[1]
total modifications	30	[1]	42	[1]	97	[1]	104	[1]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	32	[6]	60	[7]	113	[6]	171	[7]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	2	[6]	6	[7]	9	[6]	17	[7]
Residential Portfolio Segment [Member] | Residential Construction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	165	[1]	266	[1]	340	[1]	316	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0	[1],[2]	0	[1],[3]	0	[1],[2]	0	[1],[3]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	0	[1],[4]	5	[1],[5]	1	[1],[4]	15	[1],[5]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	25	[1]	29	[1]	54	[1]	30	[1]
total modifications	25	[1]	34	[1]	55	[1]	45	[1]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	6	[6]	6	[7]	23	[6]	29	[7]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	1	[6]	1	[7]	3	[6]	6	[7]
Consumer Portfolio Segment [Member] | Consumer Indirect
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	1,000	[1]			1,795	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0	[1],[2]			0	[1],[2]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	0	[1],[4]			0	[1],[4]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	17	[1]			31	[1]
total modifications	17	[1]			31	[1]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	15	[6]			15	[6]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	0	[6]			0	[6]
Consumer Portfolio Segment [Member] | Consumer Other Direct [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	42	[1]	7	[1]	81	[1]	58	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0	[1],[2]	0	[1],[3]	0	[1],[2]	0	[1],[3]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	0	[1],[4]	0	[1],[5]	0	[1],[4]	0	[1],[5]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	1	[1]	1	[1]	2	[1]	3	[1]
total modifications	1	[1]	1	[1]	2	[1]	3	[1]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	2	[6]	2	[7]	4	[6]	9	[7]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	0	[6]	0	[7]	0	[6]	0	[7]
Consumer Portfolio Segment [Member] | Consumer Credit Card Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Restructured During Period, Number Of Contracts	281	[1]	716	[1]	1,144	[1]	1,941	[1]
Financing Receivable, Amount Restructured During Period, Principal Forgiveness Granted	0	[1],[2]	0	[1],[3]	0	[1],[2]	0	[1],[3]
Financing Receivable, Amount Restructured During Period, Other Concessions Granted	2	[1],[4]	4	[1],[5]	7	[1],[4]	11	[1],[5]
Financing Receivable, Amount Restructured During Period, Term Extension and/or Other Concessions Granted	0	[1]	0	[1]	0	[1]	0	[1]
total modifications	2	[1]	4	[1]	7	[1]	11	[1]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts	33	[6]	166	[7]	168	[6]	321	[7]
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default	$ 0	[6]	$ 1	[7]	$ 1	[6]	$ 2	[7]

[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 was during the three and nine months ended September 30, 2012 was $1 million and $2 million, respectively.

[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 the three and nine months ended September 30, 2011 was $3 million and $12 million, respectively.

[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 nine months ended September 30, 2012.

[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 nine months ended September 30, 2011.

[6] For the three and nine months ended September 30, 2012, this represents defaults on loans that were first modified between the periods July 1, 2011 and September 30, 2012, and January 1, 2011 and September 30, 2012, respectively, including loans modified under the terms of a TDR that were charged-off during the periods.

[7] For the three and nine months ended September 30, 2011, this represents defaults on loans that were first modified between the periods July 1, 2010 and September 30, 2011, and January 1, 2010 and September 30, 2011, respectively, including loans modified under the terms of a TDR that were charged-off during the periods.