Income Taxes - Reconciliation Rollforward of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of gross unrecognized tax benefits
Beginning balance	$ 110	$ 100	$ 92
Additions based on tax positions related to current year	21	11	15
Reductions based on tax positions related to the current year	(1)	(1)
Additions for tax positions of prior years	5	10	39
Reductions for tax positions of prior years	(8)	(4)	(17)
Reductions due to lapse of statute of limitations	(1)	(5)
Audit settlements	(1)	(1)	(29)
Ending balance	125	110	100
Unrecognized tax benefits, net of federal tax benefits, that would affect the effective tax rate if recognized	95	80	67
Interest and penalties related to unrecognized tax benefits
Increase in interest and penalties	0	2
Decrease in interest and penalties			$ 2
Payable related to accrued interest and penalties	10	$ 10
Minimum
Reconciliation of gross unrecognized tax benefits
Estimated decrease in gross amount of unrecognized tax benefits reasonably possible in next 12 months	50
Maximum
Reconciliation of gross unrecognized tax benefits
Estimated decrease in gross amount of unrecognized tax benefits reasonably possible in next 12 months	$ 60