Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Income taxes
Effective tax rate (as a percent)	14.90%	3.70%	13.10%	4.10%
Valuation allowance	$ 11		$ 11		$ 11
Gross unrecognized tax benefits	37		37		37
Unrecognized tax benefits, net of federal tax benefits, that would affect the effective tax rate if recognized	20		20		20
Amount of decrease in unrecognized tax benefits reasonably possible within next 12 months	32		32
Interest and penalties recognized in income tax provision	0	$ 0	0	$ 0
Payable related to accrued interest and penalties	3		3		3
State deferred tax assets
Income taxes
Valuation allowance	2		2		2
State net operating losses
Income taxes
Valuation allowance	9		9		$ 9
State
Income taxes
Deferred tax assets, loss carryforwards	$ 9		$ 9