Derivative Instruments - Effect of Derivative Instruments on the Condensed Consolidated Statement of Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Effect of derivative instruments on the Consolidated Balance Sheet
Total	$ (12)	$ (66)	$ 126	$ (457)
Gas contracts
Effect of derivative instruments on the Consolidated Balance Sheet
Cash received (paid) on settlement of derivative instruments	82	(161)	181	(203)
Non-cash gain (loss) on derivative instruments	(96)	133	(54)	(49)
Oil contracts
Effect of derivative instruments on the Consolidated Balance Sheet
Cash received (paid) on settlement of derivative instruments	2	(132)	3	(261)
Non-cash gain (loss) on derivative instruments	$ 0	$ 94	$ (4)	$ 56