Income Taxes - Income (Loss) Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
United States	$ 42.1	$ 26.7	$ (86.8)
Foreign	3.6	(1.5)	0.9
Income (loss) from operations before income taxes	$ 45.7	$ 25.2	$ (85.9)