Income Taxes - Income Taxes at Federal Statutory Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Amount
Tax Expense at Federal Statutory Rate	$ 255	$ 407	$ 84
State taxes, net of federal benefit	39	70	8
Deferred adjustments	2	(6)	(5)
Nondeductible items	0	2	7
Other, net	(5)	(2)	(1)
Total income tax expense	$ 291	$ 471	$ 93
Percent
Tax Expense at Federal Statutory Rate	21.00%	21.00%	21.00%
State taxes, net of federal benefit	3.20%	3.60%	1.70%
Deferred adjustments	0.20%	(0.30%)	(1.10%)
Nondeductible items	0.00%	0.10%	1.70%
Other, net	(0.40%)	(0.10%)	(0.30%)
Total income tax expense	24.00%	24.30%	23.00%