Loans (Details Textuals) (USD $)	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Loans [Line Items]
Retained loans	$ 712,898,000,000	$ 718,997,000,000	$ 675,437,000,000
Loans (Numeric) [Abstract]
Prime mortgage loans repurchased from Government National Mortgage Association pools, which are insured by U.S. government agencies	15,800,000,000	15,600,000,000
Mortgage loans that are insured by U.S. government agencies excluded from the percentage of 30 plus days past due to retained loans	12,700,000,000	12,600,000,000
Deferred loan costs	2,700,000,000	2,700,000,000
Non performing wholesale loans restructured	837,000,000		640,000,000
Modified loans repurchased from U.S.government agencies excluded from troubled debt restructurings	4,700,000,000		4,300,000,000
Student and other loans that are 30 or more days past due and still accruing which are insured by U.S. government agencies under the Federal Family Education Loan Program	1,045,000,000	989,000,000
Total other consumer [Member]
Loans [Line Items]
Retained loans	79,921,000,000	79,221,000,000
Auto [Member]
Loans [Line Items]
Retained loans	$ 48,245,000,000	$ 47,426,000,000