Reconciliation of Income Tax Provision (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax provision at statutory rate	$ 379.8	$ 115.5	$ 128.7
Impact of goodwill impairment	0.0	21.4	0.0
Other non-deductible expenses, net	(1.2)	8.2	10.3
State income taxes, net of federal benefit	60.7	24.3	25.7
Income tax provision, excluding other reconciling items	439.3	169.4	164.7
Change in valuation allowance, net	(0.2)	0.3	0.2
Adjustments and settlements	(0.2)	0.7	0.4
Federal and state tax credits	(1.0)	(0.7)	(0.9)
Other, net	(2.8)	(1.4)	(2.6)
Income tax provision	$ 435.1	$ 168.3	$ 161.8
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax provision at statutory rate, %	21.00%	21.00%	21.00%
Impact of goodwill impairment, %	0.00%	3.90%	0.00%
Other non-deductible expenses, net, %	(0.10%)	1.50%	1.70%
State income taxes, net of federal benefit, %	3.40%	4.40%	4.20%
Income tax provision, excluding other reconciling items, %	24.30%	30.80%	26.90%
Change in valuation allowance, net, %	0.00%	0.10%	0.00%
Adjustments and settlements, %	0.00%	0.10%	0.10%
Federal and state tax credits, %	0.00%	(0.10%)	(0.20%)
Other, net, %	(0.20%)	(0.30%)	(0.40%)
Income tax provision, %	24.10%	30.60%	26.40%