Risk Management - Effect on Income Statement Not Designated (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Derivative [Line Items]
Gain/(loss) recognized in income on derivatives	$ 15	$ 78	$ (100)	$ (6)
Energy commodity derivative contracts \| Statement of Income Location Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization
Derivative [Line Items]
Gain/(loss) recognized in income on derivatives	(19)	63	(124)	(20)
Energy commodity derivative contracts \| Statement of Income Location Balance [Axis]: us-gaap:IncomeLossFromEquityMethodInvestments
Derivative [Line Items]
Gain/(loss) recognized in income on derivatives	0	2	1	0
Energy commodity derivative contracts \| Statement of Income Location Balance [Axis]: us-gaap:Revenues
Derivative [Line Items]
Gain/(loss) recognized in income on derivatives	34	13	23	16
Interest rate contracts \| Statement of Income Location Balance [Axis]: us-gaap:InterestIncomeExpenseNonoperatingNet
Derivative [Line Items]
Gain/(loss) recognized in income on derivatives	0	0	0	(2)
Derivative Contracts Settled
Derivative [Line Items]
Gain/(loss) recognized in income on derivatives	$ (58)	$ (15)	$ (89)	$ (16)