Income Taxes - Components of Consolidated Income Tax Provision (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current income tax provision -
U.S. federal	$ 199.4	$ 187.3	$ 158.0
State and local	44.3	61.7	50.1
Foreign	0.0	0.0	0.1
Total current provision for taxes	243.7	249.0	208.2
Deferred income tax provision (benefit) -
U.S. federal	3.6	86.9	62.1
State and local	1.6	(0.7)	(2.6)
Foreign	0.0	(0.2)	(0.1)
Total deferred provision for taxes	5.2	86.0	59.4
Total provision for taxes	$ 248.9	$ 335.0	$ 267.6