Schedule II - Valuation and Qualifying Accounts - Summary of Valuation Allowance (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Beginning balance			$ 14
Charged to costs and expenses				$ 14
Ending balance				14
Ending balance				14
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Beginning balance		$ 10	11	5
Charged to costs and expenses		4	2	11
Charged to other accounts		3
Deductions	[1]	(1)	(3)	(5)
Ending balance		16	10	11
Ending balance		16	10	11
SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member]
Beginning balance		15	14
Charged to costs and expenses		7	1
Ending balance		22	15	14
Ending balance		$ 22	$ 15	$ 14

[1] Deductions from allowance for doubtful accounts represent write-offs of receivable balances not considered collectible. The deduction from the valuation allowance for deferred tax assets represents changes in estimates of our future taxable income and our estimated future usage of certain net operating loss carryforwards, as well as expiration of certain net operating loss carryforwards.