Goodwill and Identifiable Intangible Assets and Liabilities - Schedule of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Roll Forward]
Balance at beginning of period	$ 2,583
Goodwill recorded in connection with the Energy Harbor Merger	224
Balance at end of period	2,807	$ 2,583
Retail Reporting Unit
Goodwill [Roll Forward]
Balance at beginning of period	2,461
Balance at end of period	2,461	2,461
Goodwill, expected tax deductible amount	$ 1,944	$ 1,944
Goodwill, expected tax deductible term	15 years	15 years
Texas Generation Reporting Unit
Goodwill [Roll Forward]
Balance at beginning of period	$ 122
Balance at end of period	$ 122	$ 122