Financial Instruments and Risk Management - Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value Measurements
Total current derivative contracts, assets	$ 57	$ 36
Total noncurrent derivative contracts, assets	16
Total current derivative contracts, liabilities	64	62
Total noncurrent derivative contracts, liabilities	1	64
Commodity contracts
Fair Value Measurements
Total current derivative contracts, assets	8	10
Total current derivative contracts, liabilities	27	53
Total noncurrent derivative contracts, liabilities	1	2
Foreign currency contracts
Fair Value Measurements
Total current derivative contracts, assets	47	21
Total noncurrent derivative contracts, assets	15
Total current derivative contracts, liabilities	18	6
Cross-currency and other contracts
Fair Value Measurements
Total current derivative contracts, assets	2	5
Total current derivative contracts, liabilities	19	3
Total noncurrent derivative contracts, liabilities		62
Interest rate and other contracts
Fair Value Measurements
Total noncurrent derivative contracts, assets	1
Derivatives Designated As Hedging Instruments
Fair Value Measurements
Total current derivative contracts, assets	13	9
Total noncurrent derivative contracts, assets	16
Total current derivative contracts, liabilities	26	45
Total noncurrent derivative contracts, liabilities	1	64
Derivatives Designated As Hedging Instruments | Commodity contracts
Fair Value Measurements
Total current derivative contracts, assets	7	9
Total current derivative contracts, liabilities	26	42
Total noncurrent derivative contracts, liabilities	1	2
Derivatives Designated As Hedging Instruments | Foreign currency contracts
Fair Value Measurements
Total current derivative contracts, assets	4
Total noncurrent derivative contracts, assets	15
Total current derivative contracts, liabilities		2
Derivatives Designated As Hedging Instruments | Cross-currency and other contracts
Fair Value Measurements
Total current derivative contracts, assets	2
Total current derivative contracts, liabilities		1
Total noncurrent derivative contracts, liabilities		62
Derivatives Designated As Hedging Instruments | Interest rate and other contracts
Fair Value Measurements
Total noncurrent derivative contracts, assets	1
Derivatives Not Designated as Hedging Instruments
Fair Value Measurements
Total current derivative contracts, assets	44	27
Total current derivative contracts, liabilities	38	17
Derivatives Not Designated as Hedging Instruments | Commodity contracts
Fair Value Measurements
Total current derivative contracts, assets	1	1
Total current derivative contracts, liabilities	1	11
Derivatives Not Designated as Hedging Instruments | Foreign currency contracts
Fair Value Measurements
Total current derivative contracts, assets	43	21
Total current derivative contracts, liabilities	18	4
Derivatives Not Designated as Hedging Instruments | Cross-currency and other contracts
Fair Value Measurements
Total current derivative contracts, assets		5
Total current derivative contracts, liabilities	$ 19	$ 2