Derivative Instruments - Balance Sheet Classification (Details) € in Millions, $ in Millions	Mar. 31, 2020 EUR (€)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 EUR (€)	Dec. 31, 2019 USD ($)	Mar. 31, 2019 EUR (€)	Mar. 31, 2019 USD ($)
Derivatives, Fair Value
Total asset derivatives		$ 92		$ 38		$ 47
Total liability derivatives		13		24		10
Current derivative asset		30		8		23
Current derivative liability		8				3
Noncurrent derivative asset		62		30		24
Noncurrent derivative liability		5		24		7
Derivatives designated as hedging instruments
Derivatives, Fair Value
Total asset derivatives		82		36		45
Total liability derivatives		8		24		9
Derivatives designated as hedging instruments | Commodity forward contracts
Derivatives, Fair Value
Notional amount		12		13		20
Total asset derivatives				1		3
Total liability derivatives		2
Derivatives designated as hedging instruments | Interest rate swaps - fair value hedges
Derivatives, Fair Value
Notional amount | €	€ 725		€ 725		€ 725
Total asset derivatives		11		8		18
Total liability derivatives				2
Derivatives designated as hedging instruments | Interest rate swaps - cash flow hedges
Derivatives, Fair Value
Notional amount		105		105		180
Total liability derivatives		2		1		1
Derivatives designated as hedging instruments | Cash flow hedges of foreign exchange risk
Derivatives, Fair Value
Notional amount		1,424		1,424		797
Total asset derivatives		66		25		18
Total liability derivatives		4		21		4
Derivatives designated as hedging instruments | Net investment hedges
Derivatives, Fair Value
Notional amount | €	€ 160		€ 160
Total asset derivatives		5		2		6
Total liability derivatives						4
Derivatives not designated as hedging instruments | Foreign exchange contracts
Derivatives, Fair Value
Notional amount		306		283		625
Total asset derivatives		10		$ 2		2
Total liability derivatives		$ 5				$ 1