Income Taxes (Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current:
Federal	$ 72.0	$ 61.7	$ 55.9
State	17.0	14.1	14.2
Foreign	13.4	4.8	9.3
Total current	102.4	80.6	79.4
Deferred:
Federal	(2.6)	(0.7)	15.0
State	(1.5)	1.1	3.9
Foreign	(2.2)	7.1	0.8
Total deferred	(6.3)	7.5	19.7
Total provision for income taxes	$ 96.1	$ 88.1	$ 99.1