Loans and Allowance for Credit Losses (Details 6) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012 Loans	Jun. 30, 2011 Loans	Jun. 30, 2012 Loans	Jun. 30, 2011 Loans
Troubled Debt Restructurings
Number of Loans	15,290	17,526	33,950	37,765
Pre-Modification Outstanding Recorded Investment	$ 676	$ 1,103	$ 1,496	$ 2,421
Post-Modification Outstanding Recorded Investment	690	1,115	1,485	2,429
Commercial Loan [Member]
Troubled Debt Restructurings
Number of Loans	1,048	1,492	2,327	2,847
Pre-Modification Outstanding Recorded Investment	70	153	161	248
Post-Modification Outstanding Recorded Investment	65	144	137	236
Commercial Real Estate Loans [Member]
Troubled Debt Restructurings
Number of Loans	71	106	182	265
Pre-Modification Outstanding Recorded Investment	121	380	325	782
Post-Modification Outstanding Recorded Investment	113	396	310	781
Residential Mortgage [Member]
Troubled Debt Restructurings
Number of Loans	450	868	1,071	1,823
Pre-Modification Outstanding Recorded Investment	74	165	185	360
Post-Modification Outstanding Recorded Investment	74	163	181	356
Credit Card [Member]
Troubled Debt Restructurings
Number of Loans	10,685	12,258	24,903	26,668
Pre-Modification Outstanding Recorded Investment	57	73	137	161
Post-Modification Outstanding Recorded Investment	56	73	136	161
Other Retail [Member]
Troubled Debt Restructurings
Number of Loans	809	1,053	1,797	2,064
Pre-Modification Outstanding Recorded Investment	20	21	35	40
Post-Modification Outstanding Recorded Investment	20	20	35	39
Total loans, excluding GNMA and covered loans [Member]
Troubled Debt Restructurings
Number of Loans	13,063	15,777	30,280	33,667
Pre-Modification Outstanding Recorded Investment	342	792	843	1,591
Post-Modification Outstanding Recorded Investment	328	796	799	1,573
Loans purchased from GNMA [Member]
Troubled Debt Restructurings
Number of Loans	2,177	1,679	3,577	3,932
Pre-Modification Outstanding Recorded Investment	277	221	456	522
Post-Modification Outstanding Recorded Investment	311	235	498	559
Covered Financing Receivable [Member]
Troubled Debt Restructurings
Number of Loans	50	70	93	166
Pre-Modification Outstanding Recorded Investment	57	90	197	308
Post-Modification Outstanding Recorded Investment	$ 51	$ 84	$ 188	$ 297