Income Taxes - Summary of Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 0.0	$ (1.4)	$ 2.2
Foreign	1.8	3.5	1.9
State and local	6.1	3.7	5.5
Total current	7.9	5.8	9.6
Deferred:
Federal	22.5	15.9	(7.0)
Foreign	(7.1)	0.4	(1.9)
State and local	(2.9)	(6.0)	(1.0)
Total deferred	12.5	10.3	(9.9)
Total income tax provision (benefit)	$ 20.4	$ 16.1	$ (0.3)