Financial Instruments - Other Comprehensive Income (Loss) (Details) - Net investment hedge - Other comprehensive income (loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Foreign currency
Derivative Instruments, Gain (Loss)
Gains and (losses) on derivative instruments	$ 0	$ 2	$ 1	$ 2
Cross-currency swaps
Derivative Instruments, Gain (Loss)
Gains and (losses) on derivative instruments	(89)	11	(71)	16
Foreign currency-denominated debt
Derivative Instruments, Gain (Loss)
Gains and (losses) on derivative instruments	$ (24)	$ 23	$ (26)	$ 28