Risk Management, Derivative Instruments and Hedging Activities - Statements of Operations Presentation (Details) - USD ($) $ in Millions	5 Months Ended	7 Months Ended	12 Months Ended
	May 17, 2023	Dec. 31, 2023	Dec. 31, 2024	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gain (loss) on commodity contracts	$ (63)	$ 52	$ 62	$ 625
Realized and unrealized gain (loss) on interest rate contracts	732	179	307	(120)
Interest rate derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Realized and unrealized gain (loss) on interest rate contracts	0	(4)	9	30
Energy Revenues
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Realized gain (loss) on commodity contracts	644	360	317	(613)
Fuel and Energy Purchases
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Realized gain (loss) on commodity contracts	(34)	(91)	(35)	127
Operating Revenues
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gain (loss) on commodity contracts	60	55	42	677
Energy Expenses
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gain (loss) on commodity contracts	$ (123)	$ (3)	$ 20	$ (52)