Derivatives - Schedule of Derivative Instruments in the Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Asset	$ 176	$ 12
Liability	21	6
Net Asset (Liability)	155	6
Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	176	10
Liability	1	6
Net Asset (Liability)	175	4
Commodity \| Derivative assets \| Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset	176	9
Liability	1	1
Net Asset (Liability)	175	8
Commodity \| Other Current Liabilities [Member] \| Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset		0
Liability		5
Net Asset (Liability)		(5)
Commodity \| Noncurrent assets \| Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Asset		1
Liability		0
Net Asset (Liability)		1
Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Asset	0	2
Liability	20	0
Net Asset (Liability)	(20)	2
Cash Flow Hedging \| Interest Rate \| Noncurrent assets
Derivatives, Fair Value [Line Items]
Asset		2
Liability		0
Net Asset (Liability)		2
Cash Flow Hedging \| Interest Rate \| Deferred credits and other liabilities
Derivatives, Fair Value [Line Items]
Asset	0
Liability	20
Net Asset (Liability)	(20)
Fair Value, Recurring [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	(155)	(6)
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	29	(3)
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	126	9
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	$ 0	$ 0

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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