Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Effective tax rate (percent)	31.10%	32.10%	31.30%	31.60%
Unrecognized tax benefits	$ 25.3		$ 25.3		$ 31.6
Unrecognized tax benefits adjusted	22.2		22.2		28.2
Amount of unrecognized tax benefits where significant change is reasonably possible	1.0		1.0		4.4
Accrued income tax interest and penalties					$ 5.7
Increase (decrease) in accrued income tax interest and penalties	$ 0.0		$ 0.0