Hedging Activities and Fair Value Measurements - Schedule of Gains and Losses on Derivative Instruments and Related Hedged Items (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ 58	$ 71	$ (44)	$ 48
Commodity Derivative Instruments | Location, Statement of Income, Balance [Axis]: us-gaap:OperatingCostsAndExpenses | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	0	3	(3)	1
Commodity Derivative Instruments | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	58	68	(41)	47
Fair value hedge | Commodity Derivative Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	0	3	(3)	4
Fair value hedge | Commodity Derivative Instruments | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Hedged Item	0	(2)	11	(2)
Cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Change in Value Recognized in Other Comprehensive Income (Loss) on Derivative	7	12	(301)	36
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) to Income	(182)	61	(139)	36
Cash flow hedge | Commodity Derivative Instruments | Location, Statement of Income, Balance [Axis]: us-gaap:OperatingCostsAndExpenses
Derivative Instruments, Gain (Loss) [Line Items]
Change in Value Recognized in Other Comprehensive Income (Loss) on Derivative	(25)	(19)	(50)	(15)
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) to Income	(11)	(8)	(21)	(20)
Cash flow hedge | Commodity Derivative Instruments | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues
Derivative Instruments, Gain (Loss) [Line Items]
Change in Value Recognized in Other Comprehensive Income (Loss) on Derivative	32	19	(251)	37
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) to Income	(173)	67	(122)	53
Cash flow hedge | Interest Rate Derivative Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Change in Value Recognized in Other Comprehensive Income (Loss) on Derivative	0	12	0	14
Cash flow hedge | Interest Rate Derivative Instruments | Location, Statement of Income, Balance [Axis]: us-gaap:InterestExpenseNonoperating
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) to Income	$ 2	$ 2	$ 4	$ 3