Fair Value Measurements and Financial Instruments - Fair Value of Derivative Instruments and Other Financial Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Designated derivative instruments
Derivative assets, designated	$ 5	$ 25
Derivative liabilities, designated	97	73
Other financial instruments
Total other financial instruments	51	14
Other current assets
Other financial instruments
Marketable securities	51	14
Other current assets | Interest rate swap contracts
Designated derivative instruments
Derivative assets, designated	0	0
Other current assets | Foreign currency contracts
Designated derivative instruments
Derivative assets, designated	5	25
Other current assets | Commodity contracts
Designated derivative instruments
Derivative assets, designated	0	0
Other assets | Interest rate swap contracts
Designated derivative instruments
Derivative assets, designated	0	0
Other assets | Foreign currency contracts
Designated derivative instruments
Derivative assets, designated	0	0
Other accruals | Interest rate swap contracts
Designated derivative instruments
Derivative liabilities, designated	6	0
Other accruals | Foreign currency contracts
Designated derivative instruments
Derivative liabilities, designated	23	20
Other accruals | Commodity contracts
Designated derivative instruments
Derivative liabilities, designated	0	0
Other liabilities | Interest rate swap contracts
Designated derivative instruments
Derivative liabilities, designated	11	7
Other liabilities | Foreign currency contracts
Designated derivative instruments
Derivative liabilities, designated	$ 57	$ 46