Income Taxes - Income Tax Expense by Component (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current:
Federal	$ 267.3	$ 281.8	$ 235.6
State	69.7	75.8	52.9
Foreign	41.6	33.9	27.4
Total current	378.6	391.5	315.9
Deferred:
Domestic	(29.3)	(15.0)	(8.7)
Foreign	(3.4)	(3.2)	2.0
Total deferred	(32.7)	(18.2)	(6.7)
Income tax expense	$ 345.9	$ 373.3	$ 309.2