Hedging Activities and Fair Value Measurements - Schedule of Recurring Fair Value Measurements (Details) - Fair Value, Recurring - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Commodity derivatives:
Impact of CME Rule 814	$ (309)	$ (223)
Total commodity derivatives	476	575
Total	476	575
Commodity derivatives:
Impact of CME Rule 814	(271)	(221)
Total commodity derivatives	418	495
Total	418	495
Commodity Derivative Before CME Rule 814
Commodity derivatives:
Total commodity derivatives	785	798
Commodity derivatives:
Total commodity derivatives	689	716
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Commodity derivatives:
Impact of CME Rule 814	(98)	(56)
Total commodity derivatives	178	299
Total	178	299
Commodity derivatives:
Impact of CME Rule 814	(28)	(43)
Total commodity derivatives	166	248
Total	166	248
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Commodity Derivative Before CME Rule 814
Commodity derivatives:
Total commodity derivatives	276	355
Commodity derivatives:
Total commodity derivatives	194	291
Significant Other Observable Inputs (Level 2)
Commodity derivatives:
Impact of CME Rule 814	(211)	(167)
Total commodity derivatives	298	276
Total	298	276
Commodity derivatives:
Impact of CME Rule 814	(242)	(157)
Total commodity derivatives	252	247
Total	252	247
Significant Other Observable Inputs (Level 2) | Commodity Derivative Before CME Rule 814
Commodity derivatives:
Total commodity derivatives	509	443
Commodity derivatives:
Total commodity derivatives	494	404
Significant Unobservable Inputs (Level 3)
Commodity derivatives:
Impact of CME Rule 814	0	0
Total commodity derivatives	0	0
Total	0	0
Commodity derivatives:
Impact of CME Rule 814	(1)	(21)
Total commodity derivatives	0	0
Total	0	0
Significant Unobservable Inputs (Level 3) | Commodity Derivative Before CME Rule 814
Commodity derivatives:
Total commodity derivatives	0	0
Commodity derivatives:
Total commodity derivatives	$ 1	$ 21