Income Taxes - Uncertain Tax Positions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning balance	$ 350.5	$ 377.1
Positions related to the current year	18.2	8.2
Positions related to prior years	28.9	3.1
Settlements with taxing authorities		(3.0)
Lapse of statutes of limitation	(2.2)	(23.5)
Decrease in prior year positions	(1.0)	(12.1)
Cumulative translation adjustment	1.6	0.7
Unrecognized tax benefits, ending balance	$ 396.0	$ 350.5