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		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Derivatives not designated as hedging instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ (22)	$ (17)	$ 26	$ (10)
Commodity Derivative Instruments | Revenue | Derivatives not designated as hedging instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	(17)	(13)	30	(5)
Commodity Derivative Instruments | Operating costs and expenses | Derivatives not designated as hedging instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	(5)	(4)	(4)	(5)
Fair value hedge
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	0	1	4	2
Gain (Loss) Recognized in Income on Hedged Item	(2)	0	(4)	5
Fair value hedge | Commodity Derivative Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ 0	$ 1	$ 4	$ 2
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Revenues	Revenues	Revenues	Revenues
Fair value hedge | Commodity Derivative Instruments | Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Hedged Item	$ (2)	$ 0	$ (4)	$ 5
Cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Change in Value Recognized in Other Comprehensive Income (Loss) on Derivative	65	206	101	125
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) to Income	37	79	73	129
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	(4)	14	(2)
Cash flow hedge | Interest Rate Derivative Instruments | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) to Income	2	2	5	5
Cash flow hedge | Commodity Derivative Instruments | Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Change in Value Recognized in Other Comprehensive Income (Loss) on Derivative	77	261	114	186
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) to Income	47	96	100	176
Cash flow hedge | Commodity Derivative Instruments | Operating costs and expenses
Derivative Instruments, Gain (Loss) [Line Items]
Change in Value Recognized in Other Comprehensive Income (Loss) on Derivative	(12)	(51)	(27)	(59)
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) to Income	$ (12)	$ (19)	$ (32)	$ (52)