Income Taxes - Reconciliation of Statutory and Effective Tax Rates (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Income tax (benefit) provision at statutory rate	$ 13.3	$ 14.4	$ (22.5)
Foreign taxes	0.9	0.9	1.9
State and local income taxes, net of federal income tax	(3.7)	3.6	2.6
Federal and foreign	3.1	1.1	0.5
Enactment of the 2017 Tax Act	0.0	20.8	207.1
Finalization of estimates from Spin-Off	0.0	0.0	(0.9)
Change in valuation allowance	2.6	(1.5)	1.1
Outside basis difference in foreign subsidiaries	(0.9)	0.9	0.0
All other items, net	0.8	1.1	(0.3)
Total income tax provision (benefit)	$ 16.1	$ (0.3)	$ (224.7)