Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income tax expense	$ 6.0	$ 10.7	$ 11.3	$ 14.0
Pre-tax earnings (loss)	$ 22.2	$ 28.0	$ 43.4	$ 38.0
Effective tax rate (as a percent)			26.10%	36.90%