Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Income tax provision	$ 11.9	$ 5.6	$ 15.2	$ 9.1
Uncertain income tax positions	28.4		28.4
Penalties and interest accrued	$ 2.5		2.5
Decrease in unrecognized tax benefits result from resolution of outstanding positions			23.3
Cash refund for income taxes			$ 21.3	$ 0.2