Income Taxes - Provision (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ (12.0)	$ 25.1	$ 61.9
Foreign	77.0	90.0	49.9
State	0.4	(0.4)	4.1
Total current	65.4	114.7	115.9
Deferred:
Federal	(1.2)	(4.4)	127.8
Foreign	42.7	(30.4)	(14.4)
State	4.6	(9.1)	(0.4)
Total deferred	46.1	(43.9)	113.0
Total	$ 111.5	$ 70.8	$ 228.9