Income Taxes - Significant Components (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ (0.2)	$ 4.9	$ (3.2)
State and local	1.9	2.7	(0.2)
Foreign	12.2	11.4	5.3
Total current	13.9	19.0	1.9
Deferred:
Federal	7.5	(2.0)	3.8
State and local	(2.9)	(5.5)	1.5
Foreign	(3.6)	(8.7)	0.0
Total deferred	1.0	(16.2)	5.3
Income tax expense (benefit), net	$ 14.9	$ 2.8	$ 7.2