Accounting for Derivative Instruments and Hedging Activities - Pre-tax Effects of Economic Hedges not Designated as Cash Flow Hedges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Unrealized Mark To Market Results [Abstract]
Reversal of previously recognized unrealized (gains)/losses on settled positions related to economic hedges	$ (432)	$ 106	$ (1,734)
Reversal of acquired loss positions related to economic hedges	47	5	20
Net unrealized gains/(losses) on open positions related to economic hedges	39	95	(1,149)
Total unrealized mark-to-market (losses)/gains for economic hedging activities	(346)	206	(2,863)
Reversal of previously recognized unrealized losses/(gains) on settled positions related to trading activity	2	(1)	13
Net unrealized gains on open positions related to trading activity	3	2	25
Total unrealized mark-to-market gains for trading activity	5	1	38
Total unrealized (losses)/gains - commodities and foreign exchange	(341)	207	(2,825)
Credit Risk Related Contingent Features [Abstract]
Collateral required contracts with credit rating contingent features in a net liability position	207
Additional collateral required	55
Adequate Assurance Clauses
Credit Risk Related Contingent Features [Abstract]
Collateral required for contracts in net liability positions that have adequate assurance clauses	1,000
Interest rate contracts
Unrealized Mark To Market Results [Abstract]
Total impact to statement of operations	(10)	3	4
Commodities | Operating revenue
Unrealized Mark To Market Results [Abstract]
Total unrealized (losses)/gains - commodities and foreign exchange	17	(2)	182
Commodities | Cost of operations
Unrealized Mark To Market Results [Abstract]
Total unrealized (losses)/gains - commodities and foreign exchange	(338)	186	(2,988)
Foreign exchange | Cost of operations
Unrealized Mark To Market Results [Abstract]
Total unrealized (losses)/gains - commodities and foreign exchange	(20)	23	(19)
Commodity and foreign exchange
Unrealized Mark To Market Results [Abstract]
Total unrealized (losses)/gains - commodities and foreign exchange	(341)	207	(2,825)
Derivative Contract-NPNS
Unrealized Mark To Market Results [Abstract]
Reversal of previously recognized unrealized (gains)/losses on settled positions related to economic hedges	(286)	37
Consumer Financing Program
Unrealized Mark To Market Results [Abstract]
Total impact to statement of operations	$ (21)	$ (14)	$ (16)