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				9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2021	Sep. 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	$ (483)			$ 33		$ (862)	$ 30
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	7			(2)		23	3
Purchased commodities [Member] \| Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) from commodity derivatives	$ 405			$ (27)		$ 550	$ (29)