Schedule II - Valuation And Qualifying Accounts (Details) - Allowance for doubtful accounts - 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]
Balance at beginning of period	$ 105	$ 103	$ 100
Charged to costs & expenses	31	30	31
Impact of currency	4	(1)	(4)
Charged to other accounts	14	0	1
Write-offs, write-downs & deductions	(20)	(27)	(25)
Balance at end of period	$ 134	$ 105	$ 103