Derivative Instruments - Balance Sheet Classification (Details) € in Millions, $ in Millions	Sep. 30, 2021 USD ($)	Sep. 30, 2021 EUR (€)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 EUR (€)
Derivatives, Fair Value
Total asset derivatives	$ 21		$ 25		$ 30
Total liability derivatives	87		170		100
Current derivative asset	15		13		16
Current derivative liability	4		15		13
Noncurrent derivative asset	6		12		14
Noncurrent derivative liability	83		155		87
Derivatives designated as hedging instruments
Derivatives, Fair Value
Total asset derivatives	20		24		27
Total liability derivatives	83		167		94
Derivatives designated as hedging instruments | Interest rate swaps - fair value hedges
Derivatives, Fair Value
Notional amount | €		€ 725		€ 725		€ 725
Total asset derivatives	9		17		16
Total liability derivatives	1
Derivatives designated as hedging instruments | Cash flow hedges of foreign exchange risk
Derivatives, Fair Value
Notional amount	878		978		1,100
Total asset derivatives	9		6		9
Total liability derivatives	54		115		67
Derivatives designated as hedging instruments | Net investment hedges
Derivatives, Fair Value
Notional amount | €		€ 311		€ 311		€ 311
Total asset derivatives	2		1		2
Total liability derivatives	28		52		27
Derivatives not designated as hedging instruments | Foreign exchange contracts
Derivatives, Fair Value
Notional amount	291		247		247
Total asset derivatives	1		1		3
Total liability derivatives	$ 4		$ 3		$ 6