SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Translation Adjustment	$ 214
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	29	$ 25	$ 22
Additions - Charged (Credited) To Costs And Expenses	1	10	6
Additions - Charged to Other Accounts	(2)	1	1
Write-offs Net of Recoveries	(12)	(6)	(2)
Translation Adjustment	2	(1)	(2)
Balance at End of Period	18	29	25
Deferred tax asset valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	288	288	3,015
Additions - Charged (Credited) To Costs And Expenses	(5)	8	108
Additions - Charged to Other Accounts	0	0	0
Write-offs Net of Recoveries	(2)	(6)	(2,769)
Translation Adjustment	6	(2)	(66)
Balance at End of Period	$ 287	$ 288	$ 288