Hedging Activities and Fair Value Measurements, Recurring Fair Value Measurements (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financial assets [Abstract]
Value before application of CME Rule 814	$ 798	$ 728
Impact of CME Rule 814	(223)	(278)
Total commodity derivatives	575	450
Total	575	450
Financial liabilities [Abstract]
Interest rate derivatives		31
Commodity derivatives:
Value before application of CME Rule 814	716	625
Impact of CME Rule 814	(221)	(154)
Total commodity derivatives	495	471
Total	495	502
Net value before application of CME Rule 814 to commodity hedging portfolio	82
Level 1 [Member]
Financial assets [Abstract]
Value before application of CME Rule 814	355	431
Impact of CME Rule 814	(56)	(147)
Total commodity derivatives	299	284
Total	299	284
Financial liabilities [Abstract]
Interest rate derivatives		0
Commodity derivatives:
Value before application of CME Rule 814	291	317
Impact of CME Rule 814	(43)	(22)
Total commodity derivatives	248	295
Total	248	295
Level 2 [Member]
Financial assets [Abstract]
Value before application of CME Rule 814	443	297
Impact of CME Rule 814	(167)	(131)
Total commodity derivatives	276	166
Total	276	166
Financial liabilities [Abstract]
Interest rate derivatives		31
Commodity derivatives:
Value before application of CME Rule 814	404	308
Impact of CME Rule 814	(157)	(132)
Total commodity derivatives	247	176
Total	247	207
Level 3 [Member]
Financial assets [Abstract]
Value before application of CME Rule 814	0	0
Impact of CME Rule 814	0	0
Total commodity derivatives	0	0
Total	0	0
Financial liabilities [Abstract]
Interest rate derivatives		0
Commodity derivatives:
Value before application of CME Rule 814	21	0
Impact of CME Rule 814	(21)	0
Total commodity derivatives	0	0
Total	$ 0	$ 0