Financial Instruments and Risk Management - Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Fair Value Measurements
Total current derivative contracts, assets	$ 41	$ 57
Total noncurrent derivative contracts, assets	73	16
Total current derivative contracts, liabilities	89	64
Total noncurrent derivative contracts, liabilities	5	1
Commodity contracts
Fair Value Measurements
Total current derivative contracts, assets	26	8
Total noncurrent derivative contracts, assets	4
Total current derivative contracts, liabilities	67	27
Total noncurrent derivative contracts, liabilities	4	1
Foreign currency contracts
Fair Value Measurements
Total current derivative contracts, assets	11	47
Total noncurrent derivative contracts, assets	69	15
Total current derivative contracts, liabilities	17	18
Total noncurrent derivative contracts, liabilities	1
Other contracts
Fair Value Measurements
Total current derivative contracts, assets	4	2
Total noncurrent derivative contracts, assets		1
Total current derivative contracts, liabilities	5	19
Derivatives Designated As Hedging Instruments
Fair Value Measurements
Total current derivative contracts, assets	26	13
Total noncurrent derivative contracts, assets	72	16
Total current derivative contracts, liabilities	68	26
Total noncurrent derivative contracts, liabilities	4	1
Derivatives Designated As Hedging Instruments | Commodity contracts
Fair Value Measurements
Total current derivative contracts, assets	26	7
Total noncurrent derivative contracts, assets	4
Total current derivative contracts, liabilities	66	26
Total noncurrent derivative contracts, liabilities	4	1
Derivatives Designated As Hedging Instruments | Foreign currency contracts
Fair Value Measurements
Total current derivative contracts, assets		4
Total noncurrent derivative contracts, assets	68	15
Derivatives Designated As Hedging Instruments | Other contracts
Fair Value Measurements
Total current derivative contracts, assets		2
Total noncurrent derivative contracts, assets		1
Total current derivative contracts, liabilities	2
Derivatives Not Designated as Hedging Instruments
Fair Value Measurements
Total current derivative contracts, assets	15	44
Total noncurrent derivative contracts, assets	1
Total current derivative contracts, liabilities	21	38
Total noncurrent derivative contracts, liabilities	1
Derivatives Not Designated as Hedging Instruments | Commodity contracts
Fair Value Measurements
Total current derivative contracts, assets		1
Total current derivative contracts, liabilities	1	1
Derivatives Not Designated as Hedging Instruments | Foreign currency contracts
Fair Value Measurements
Total current derivative contracts, assets	11	43
Total noncurrent derivative contracts, assets	1
Total current derivative contracts, liabilities	17	18
Total noncurrent derivative contracts, liabilities	1
Derivatives Not Designated as Hedging Instruments | Other contracts
Fair Value Measurements
Total current derivative contracts, assets	4
Total current derivative contracts, liabilities	$ 3	$ 19