Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees, Other Commitments (Details) (New Markets Tax Credit [Member], USD $)	3 Months Ended
	Mar. 31, 2015	Aug. 31, 2008
New Markets Tax Credit [Member]
Other Commitments [Line Items]
Membership interest in U.S Bank New Markets Tax Credit Fund (in hundredths)		99.90%
Equity contributions to be made to the Fund	$ 283,700,000
Net tax benefits to be received from the Fund	302,000,000
Difference between equity contributions and total benefits received will be recognized over the life of the Fund as net tax benefits	18,300,000
Future equity contributions to the NMTC Fund [Abstract]
Nine months ending Dec. 31, 2015	4,091,000
Year ending Dec. 31, 2016	2,707,000
Year ending Dec. 31, 2017	2,707,000
Total	9,505,000
Total future equity contributions	9,505,000
Future equity contributions due within the next 12 months	4,100,000
Tax Benefits in Excess of Capital Contributions	27,000,000
Tax benefits not utilized	120,200,000
Equity contributions, imputed interest rate 6%[Abstract]
Equity contributions - imputed interst rate (in hundredths)	6.00%
Principal payment schedule above:	9,505,000
Less: unamortized discount	726,000
Total	$ 8,779,000
Period of recognition of gross investment amortization expense (in years)	9 years
Remaining period of recognition of gross investment amortization expense (in years)	3 years