Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income before income taxes:
United States	$ 372.0	$ 406.7	$ 360.8
International	81.5	113.8	106.2
Income before income taxes	453.5	520.5	467.0
Provision for income taxes — current:
Federal	60.7	65.0	12.3
State	16.1	16.6	21.8
International	17.4	25.4	17.8
Total provision — current	94.2	107.0	51.9
Provision for income taxes — deferred:
Federal	2.4	8.6	35.0
State	1.0	0.5	9.4
International	(0.1)	(3.0)	4.6
Total provision — deferred	3.3	6.1	49.0
TOTAL PROVISION FOR INCOME TAXES	$ 97.5	$ 113.1	$ 100.9