Hedging Activities and Fair Value Measurements - Schedule of Recurring Fair Value Measurements (Details) - Fair Value, Recurring - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Commodity derivatives:
Impact of CME Rule 814	$ (410)	$ (489)
Total commodity derivatives	707	460
Total	707	460
Commodity derivatives:
Impact of CME Rule 814	(504)	(379)
Total commodity derivatives	680	363
Total	680	363
Commodity Derivative Before CME Rule 814
Commodity derivatives:
Total commodity derivatives	1,117	949
Commodity derivatives:
Total commodity derivatives	1,184	742
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Commodity derivatives:
Impact of CME Rule 814	(135)	(170)
Total commodity derivatives	179	2
Total	179	2
Commodity derivatives:
Impact of CME Rule 814	(256)	(31)
Total commodity derivatives	194	1
Total	194	1
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Commodity Derivative Before CME Rule 814
Commodity derivatives:
Total commodity derivatives	314	172
Commodity derivatives:
Total commodity derivatives	450	32
Significant Other Observable Inputs (Level 2)
Commodity derivatives:
Impact of CME Rule 814	(275)	(319)
Total commodity derivatives	527	458
Total	527	458
Commodity derivatives:
Impact of CME Rule 814	(248)	(348)
Total commodity derivatives	486	362
Total	486	362
Significant Other Observable Inputs (Level 2) | Commodity Derivative Before CME Rule 814
Commodity derivatives:
Total commodity derivatives	802	777
Commodity derivatives:
Total commodity derivatives	734	710
Significant Unobservable Inputs (Level 3)
Commodity derivatives:
Impact of CME Rule 814	0	0
Total commodity derivatives	1	0
Total	1	0
Commodity derivatives:
Impact of CME Rule 814	0	0
Total commodity derivatives	0	0
Total	0	0
Significant Unobservable Inputs (Level 3) | Commodity Derivative Before CME Rule 814
Commodity derivatives:
Total commodity derivatives	1	0
Commodity derivatives:
Total commodity derivatives	$ 0	$ 0