Financial Instruments, Derivatives and Hedging Activities - Balance Sheet Location (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Designated as Hedging Instrument
Fair value of derivatives
Fair value of derivative instruments, Assets	$ 19	$ 17
Fair value of derivative instruments, Liabilities	57	25
Fair value of derivative instruments, Net Assets/(Liabilities)	(38)	(8)
Designated as Hedging Instrument | Accounts receivable, net
Fair value of derivatives
Fair value of derivative instruments, Assets	11	12
Designated as Hedging Instrument | Other assets
Fair value of derivatives
Fair value of derivative instruments, Assets	8	5
Designated as Hedging Instrument | Accounts payable and accrued liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	53	17
Designated as Hedging Instrument | Non-current liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	4	8
Designated as Hedging Instrument | Commodity Contracts
Fair value of derivatives
Fair value of derivative instruments, Assets	1	6
Fair value of derivative instruments, Liabilities	40	17
Fair value of derivative instruments, Net Assets/(Liabilities)	(39)	(11)
Designated as Hedging Instrument | Commodity Contracts | Accounts receivable, net
Fair value of derivatives
Fair value of derivative instruments, Assets	1	5
Designated as Hedging Instrument | Commodity Contracts | Other assets
Fair value of derivatives
Fair value of derivative instruments, Assets		1
Designated as Hedging Instrument | Commodity Contracts | Accounts payable and accrued liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	37	13
Designated as Hedging Instrument | Commodity Contracts | Non-current liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	3	4
Designated as Hedging Instrument | Foreign Currency Forward Contracts
Fair value of derivatives
Fair value of derivative instruments, Assets	14	10
Fair value of derivative instruments, Liabilities	13	8
Fair value of derivative instruments, Net Assets/(Liabilities)	1	2
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Accounts receivable, net
Fair value of derivatives
Fair value of derivative instruments, Assets	10	7
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Other assets
Fair value of derivatives
Fair value of derivative instruments, Assets	4	3
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Accounts payable and accrued liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	12	4
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Non-current liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	1	4
Designated as Hedging Instrument | Interest Rate Contracts
Fair value of derivatives
Fair value of derivative instruments, Assets	4	1
Fair value of derivative instruments, Liabilities	4
Fair value of derivative instruments, Net Assets/(Liabilities)		1
Designated as Hedging Instrument | Interest Rate Contracts | Other assets
Fair value of derivatives
Fair value of derivative instruments, Assets	4	1
Designated as Hedging Instrument | Interest Rate Contracts | Accounts payable and accrued liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	4
Not Designated as Hedging Instrument
Fair value of derivatives
Fair value of derivative instruments, Assets	13	7
Fair value of derivative instruments, Liabilities	20	11
Fair value of derivative instruments, Net Assets/(Liabilities)	(7)	(4)
Not Designated as Hedging Instrument | Accounts receivable, net
Fair value of derivatives
Fair value of derivative instruments, Assets	13	6
Not Designated as Hedging Instrument | Other assets
Fair value of derivatives
Fair value of derivative instruments, Assets		1
Not Designated as Hedging Instrument | Accounts payable and accrued liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	19	9
Not Designated as Hedging Instrument | Non-current liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	1	2
Not Designated as Hedging Instrument | Commodity Contracts
Fair value of derivatives
Fair value of derivative instruments, Assets		2
Fair value of derivative instruments, Liabilities	9	1
Fair value of derivative instruments, Net Assets/(Liabilities)	(9)	1
Not Designated as Hedging Instrument | Commodity Contracts | Accounts receivable, net
Fair value of derivatives
Fair value of derivative instruments, Assets		2
Not Designated as Hedging Instrument | Commodity Contracts | Accounts payable and accrued liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	9	1
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts
Fair value of derivatives
Fair value of derivative instruments, Assets	13	5
Fair value of derivative instruments, Liabilities	11	10
Fair value of derivative instruments, Net Assets/(Liabilities)	2	(5)
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts | Accounts receivable, net
Fair value of derivatives
Fair value of derivative instruments, Assets	13	4
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts | Other assets
Fair value of derivatives
Fair value of derivative instruments, Assets		1
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts | Accounts payable and accrued liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	10	8
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts | Non-current liabilities
Fair value of derivatives
Fair value of derivative instruments, Liabilities	$ 1	$ 2