Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees, Other Commitments (Details) - NMTC [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Aug. 31, 2008
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	$ 283.7
Net tax benefits and cash to be received from the Fund	302.0
Difference between equity contributions and total benefits received	18.3
Tax Benefits in Excess of Capital Contributions	17.8
Tax benefits not utilized	$ 99.6
Period of recognition of gross investment amortization expense (in years)	9 years
Remaining period of recognition of gross investment amortization expense (in years)	2 years