Income Taxes - Summary of Income Tax Provision (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 0.0	$ 0.0	$ (0.9)
State	(3.3)	5.4	0.8
Foreign	2.0	6.8	6.0
Current income tax expense (benefit)	(1.3)	12.2	5.9
Deferred:
Federal	0.0	0.0	(13.3)
State	0.0	0.0	0.0
Foreign	(3.0)	(1.1)	0.1
Deferred income tax benefit	(3.0)	(1.1)	(13.2)
Income tax expense (benefit)	(4.3)	11.1	(7.3)
Domestic	(104.7)	13.6	(30.5)
Foreign	(3.6)	17.7	12.4
Income (loss) before income taxes	$ (108.3)	$ 31.3	$ (18.1)