Income Taxes - Schedule of Reconciliation of Income Tax Expense (Benefit) Computed by Applying Statutory Federal Income Tax Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Amount
Computed “expected” federal income tax	$ 315	$ 51	$ 189
State income tax, net of federal income tax benefit	24	5	15
Deferred tax adjustment related to change in overall state tax rate	(7)	1	(1)
Valuation allowance	3	(4)	18
Excess executive compensation	15	5	2
Reserve on uncertain tax positions	1	6	0
Uncertain tax positions	(6)	(23)	0
Other, net	(1)	0	(4)
Income tax expense	$ 344	$ 41	$ 219
Rate
Computed “expected” federal income tax	21.00%	21.00%	21.00%
State income tax, net of federal income tax benefit	1.59%	1.86%	1.64%
Deferred tax adjustment related to change in overall state tax rate	(0.46%)	0.50%	(0.07%)
Valuation allowance	0.22%	(1.58%)	1.96%
Excess executive compensation	1.03%	2.18%	0.21%
Reserve on uncertain tax positions	0.05%	2.47%	0.00%
Uncertain tax positions	(0.39%)	(9.63%)	0.00%
Other, net	(0.14%)	0.04%	(0.40%)
Income tax expense	22.90%	16.84%	24.34%