Fair value, before effects of master netting arrangements, of a financial liability or 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 liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Fair Value of Financial Instruments - Recurring Fair Value (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value, gross liability	$ 186						$ 186		$ 92
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Change in unrealized losses included in earnings for derivatives held as of September 30, 2020	8	$ 4	$ (12)	$ (1)	$ 5	$ (2)
Fair Value, Recurring \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value, gross liability	169						169		83
Fair Value, Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value, gross liability	17						17		9
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	(17)		$ (9)	(7)		$ 0	(9)	$ 0
Total losses for the period included in earnings	0			(2)			(8)	(2)
Purchases	0			0			0	(7)
Ending balance	(17)	$ (17)		(9)	$ (7)		(17)	(9)
Change in unrealized losses included in earnings for derivatives held as of September 30, 2020	0						8
Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value, gross liability	17						17		9
Commodity contracts \| Fair Value, Recurring \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value, gross liability	0						0		0
Commodity contracts \| Fair Value, Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value, gross liability	17						17		9
Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value, gross liability	169						169		83
Interest rate contracts \| Fair Value, Recurring \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value, gross liability	169						169		83
Interest rate contracts \| Fair Value, Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value, gross liability	$ 0						$ 0		$ 0