Revenue - Summary of Components of Operating Revenues (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
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 478	$ 1,165	$ 1,574	$ 3,209
Realized and unrealized gain (loss) on derivative instruments	732	179	307	(120)
Nuclear PTC	0	0	220	0
Other revenue	0	0	14	0
Operating revenues	1,210	1,344	2,115	3,089
Amount of PTC revenue utilized as a credit against Federal Income Taxes payable			70
Capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	108	133	192	377
Operating revenues	108	133	192	377
Electricity sales and ancillary services, ISO/RTO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	281	880	1,144	2,534
Physical electricity sales, bilateral contracts, other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	62	71	147	298
Other revenue from customers
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 27	$ 81	$ 91	$ 0