Derivative Instruments - Balance Sheet Classification (Details) € in Millions, $ in Millions	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)
Derivatives, Fair Value
Total asset derivatives	$ 25		$ 38
Total liability derivatives	170		24
Current derivative asset	13		8
Current derivative liability	15
Noncurrent derivative asset	12		30
Noncurrent derivative liability	155		24
Derivatives designated as hedging instruments
Derivatives, Fair Value
Total asset derivatives	24		35
Total liability derivatives	167		24
Derivatives designated as hedging instruments | Interest rate swaps - fair value hedges
Derivatives, Fair Value
Notional amount | €		€ 725		€ 725
Total asset derivatives	17		8
Total liability derivatives			2
Derivatives designated as hedging instruments | Cash flow hedges of foreign exchange risk
Derivatives, Fair Value
Notional amount	978		1,424
Total asset derivatives	6		25
Total liability derivatives	115		21
Derivatives designated as hedging instruments | Interest rate swaps - cash flow hedges
Derivatives, Fair Value
Notional amount	0		105
Total liability derivatives			1
Derivatives designated as hedging instruments | Net investment hedges
Derivatives, Fair Value
Total asset derivatives	1		2
Total liability derivatives	52
Derivatives not designated as hedging instruments | Foreign exchange derivative contracts
Derivatives, Fair Value
Notional amount	247		283
Total asset derivatives	1		$ 3
Total liability derivatives	$ 3
Net investment hedges | Derivatives designated as hedging instruments
Derivatives, Fair Value
Notional amount | €		€ 311		€ 311