Schedule II, Valuation and Qualifying Accounts (Details) - Allowance for Bad Debts - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Jan. 1		$ 33	$ 23	$ 24
Charged to costs and expenses		24	24	13
Charged to other accounts	[1]	5	5	7
Deductions from reserves	[2]	(17)	(19)	(21)
Balance at Dec. 31		$ 45	$ 33	$ 23

[1] Recovery of amounts previously written-off.

[2] Deductions related primarily to bad debt write-offs.