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

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Amount of gain (loss) recognized in earnings in the period from the increase (decrease) in fair value of price risk derivatives not designated as hedging instruments.

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The increase (decrease) during the reporting period in the assets (liabilities) created through trading commodity-based derivative instruments.

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Derivative and Financial Instruments - Commodity Gain (Loss) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Jan. 15, 2021
Commodity Contract [Member] \| Concho Resources Incorporated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) from commodity derivatives		$ (305)		$ (233)
Derivative, Fair Value, Net							$ (456)
Increase (Decrease) in Commodity Contract Assets and Liabilities	$ 69	692
Sales and other operating revenues [Member] \| Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) from commodity derivatives	(100)		$ (50)		$ (379)	$ (3)
Sales and other operating revenues [Member] \| Commodity Contract [Member] \| Concho Resources Incorporated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) from commodity derivatives		(173)		$ (305)
Sales and other operating revenues [Member] \| Accelerated contracts [Member] \| Concho Resources Incorporated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) from commodity derivatives		$ (132)
Other Income (Loss) [Member] \| Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) from commodity derivatives	(1)		3		16	5
Purchased commodities [Member] \| Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) from commodity derivatives	$ 132		$ 24		$ 145	$ (2)