Income Taxes - Reconciliation of our Uncertain Tax Positions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Uncertain tax positions -
Balance January 1	$ 208	$ 215	$ 224
Gross increases in tax positions in current period	6	4	12
Gross increases in tax positions in prior period	2	14	4
Gross decreases in tax positions in prior period	(67)	(7)	(5)
Gross decreases - settlements	0	0	(12)
Gross decreases - statute of limitations expired	(21)	(18)	(8)
Balance December 31	$ 128	$ 208	$ 215