Derivatives - Schedule of Derivative Instruments in the Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Asset	$ 102	$ 12
Liability	47	6
Net Asset (Liability)	55	6
Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	100	10
Liability	21	6
Net Asset (Liability)	79	4
Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	2	2
Liability	26	0
Net Asset (Liability)	(24)	2
Commodity \| Derivative assets \| Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	100	9
Liability	21	1
Net Asset (Liability)	79	8
Commodity \| Other current liabilities \| Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset		0
Liability		5
Net Asset (Liability)		(5)
Commodity \| Other noncurrent assets \| Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset		1
Liability		0
Net Asset (Liability)		1
Interest Rate \| Deferred credits and other liabilities \| Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	0
Liability	26
Net Asset (Liability)	(26)
Interest Rate \| Other noncurrent assets \| Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Asset	2	2
Liability	0	0
Net Asset (Liability)	$ 2	$ 2

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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