Accounting for Derivative Instruments and Hedging Activities - Fair Value Within the Derivative Instrument Valuation (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Derivative [Line Items]
Derivative Assets	$ 3,757	$ 4,396
Derivative Liabilities	$ 3,360	3,404
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Derivative Instruments and Hedges, Assets
Deferred gains/losses on NPNS contracts - current
Derivative [Line Items]
Derivative Assets	$ 196	376
Derivative Liabilities	71	90
Deferred gains/losses on NPNS contracts - long-term
Derivative [Line Items]
Derivative Assets	426	621
Derivative Liabilities	67	137
Derivative Contract-NPNS
Derivative [Line Items]
Derivative Assets	622	997
Derivative Liabilities	138	227
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets	3,135	3,399
Derivative Liabilities	3,222	3,177
Not Designated as Hedging Instrument | Interest rate contracts - current
Derivative [Line Items]
Derivative Assets	0	0
Derivative Liabilities	4	3
Not Designated as Hedging Instrument | Interest rate contracts long-term
Derivative [Line Items]
Derivative Assets	0	9
Derivative Liabilities	0	0
Not Designated as Hedging Instrument | Foreign exchange contracts - current
Derivative [Line Items]
Derivative Assets	2	15
Derivative Liabilities	1	0
Not Designated as Hedging Instrument | Foreign exchange contracts - long-term
Derivative [Line Items]
Derivative Assets	1	7
Derivative Liabilities	2	1
Not Designated as Hedging Instrument | Commodity contracts - current
Derivative [Line Items]
Derivative Assets	1,991	2,295
Derivative Liabilities	1,997	2,067
Not Designated as Hedging Instrument | Commodity contracts - long-term
Derivative [Line Items]
Derivative Assets	1,141	1,073
Derivative Liabilities	935	903
Not Designated as Hedging Instrument | Consumer Financing Program - current
Derivative [Line Items]
Derivative Assets	0	0
Derivative Liabilities	184	137
Not Designated as Hedging Instrument | Consumer Financing Program - long-term
Derivative [Line Items]
Derivative Assets	0	0
Derivative Liabilities	$ 99	$ 66