Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees, New Markets Tax Credits (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Aug. 31, 2008
Equity contributions with an imputed interest rate [Abstract]
Equity contributions - imputed interest rate (in hundredths)	6.00%
Tax Credit Fund Investment, Net, Liability	$ 0	$ 41,840,000
Tax Credit Fund Investment, Net, Asset	7,251,000	0
New Markets Tax Credit [Member]
Other Commitments [Line Items]
Equity contributions - Total	9,966,000
New Markets Tax Credits [Abstract]
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 [Abstract]
2015	4,552,000
2016	2,707,000
2017	2,707,000
Total	9,966,000
Equity contributions with an imputed interest rate [Abstract]
Less: unamortized discount	862,000
Total	9,104,000
Tax benefits in excess of capital contributions	25,900,000
Tax benefits not utilized	119,400,000
Period (in years) over which gross investment amortization expense is recognized	9 years
Remaining period (in years) of recognition of gross investment amortization expense	3 years
Contributions Made to Tax Credit Fund	55,300,000
Reduction to Gross Liability of Tax Credit Fund	$ 52,600,000