Income Taxes - Schedule of a Reconciliation of the Provision for Income Taxes at the U.S. Federal Statutory Income Tax Rate to the Actual Income Tax Provision (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of provision for income taxes at U.S. federal statutory income tax rate to effective income tax rate
(Benefit) provision for taxes at U.S. federal statutory rate	$ (5.8)	$ 79.7	$ 70.0
State and local taxes, net of federal benefit	(4.2)	3.6	7.2
Foreign effective rate differential	(1.9)	5.1	4.6
Tax credits	(3.0)	(8.8)	(7.8)
Change in valuation allowance	(39.5)	(1.9)	(3.4)
Remeasurement of deferred taxes	3.5	0.4	(9.0)
Transition tax on undistributed foreign earnings			1.6
Excess tax benefits on stock-based compensation	(0.9)	(4.9)	(4.6)
Other	(4.3)	1.0	(0.5)
(Decrease) increase in reserves for uncertain tax positions	(4.9)	1.2	(1.3)
Global intangible low taxed income		1.4	5.7
Total income tax (benefit) expense	$ (61.0)	$ 76.8	$ 62.5