Income Taxes - Schedule of the Components of Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal and state	$ 21.9	$ 15.7	$ 51.1
Foreign	26.2	19.5	18.2
Total current expense	48.1	35.2	69.3
Deferred:
Federal and state	(55.6)	(15.5)	(27.9)
Foreign	(7.7)	5.6	(2.1)
Total deferred benefit	(63.3)	(9.9)	(30.0)
Income taxes	$ (15.2)	$ 25.3	$ 39.3