Loans and Allowance for Credit Losses (Details 6) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Troubled Debt Restructurings
Number of Loans	$ 18,660	$ 20,239,000,000
Pre-Modification Outstanding Recorded Investment	820,000,000	1,318,000,000
Post-Modification Outstanding Recorded Investment	795,000,000	1,314,000,000
Commercial Loan [Member]
Troubled Debt Restructurings
Number of Loans	1,279	1,355,000,000
Pre-Modification Outstanding Recorded Investment	91,000,000	95,000,000
Post-Modification Outstanding Recorded Investment	72,000,000	92,000,000
Commercial Real Estate Loans [Member]
Troubled Debt Restructurings
Number of Loans	111	159,000,000
Pre-Modification Outstanding Recorded Investment	204,000,000	402,000,000
Post-Modification Outstanding Recorded Investment	197,000,000	385,000,000
Residential Mortgage [Member]
Troubled Debt Restructurings
Number of Loans	621	955,000,000
Pre-Modification Outstanding Recorded Investment	111,000,000	195,000,000
Post-Modification Outstanding Recorded Investment	107,000,000	193,000,000
Credit Card [Member]
Troubled Debt Restructurings
Number of Loans	14,218	14,410,000,000
Pre-Modification Outstanding Recorded Investment	80,000,000	88,000,000
Post-Modification Outstanding Recorded Investment	80,000,000	88,000,000
Other Retail [Member]
Troubled Debt Restructurings
Number of Loans	988	1,011,000,000
Pre-Modification Outstanding Recorded Investment	15,000,000	19,000,000
Post-Modification Outstanding Recorded Investment	15,000,000	19,000,000
Total loans, excluding GNMA and covered loans [Member]
Troubled Debt Restructurings
Number of Loans	17,217	17,890,000,000
Pre-Modification Outstanding Recorded Investment	501,000,000	799,000,000
Post-Modification Outstanding Recorded Investment	471,000,000	777,000,000
Loans purchased from GNMA [Member]
Troubled Debt Restructurings
Number of Loans	1,400	2,253,000,000
Pre-Modification Outstanding Recorded Investment	179,000,000	301,000,000
Post-Modification Outstanding Recorded Investment	187,000,000	324,000,000
Covered Financing Receivable [Member]
Troubled Debt Restructurings
Number of Loans	43	96,000,000
Pre-Modification Outstanding Recorded Investment	140,000,000	218,000,000
Post-Modification Outstanding Recorded Investment	$ 137,000,000	$ 213,000,000