Income Taxes - Narrative (Details) - USD ($)	Feb. 26, 2024	Dec. 31, 2023	Dec. 31, 2022	Feb. 01, 2022	Dec. 31, 2021
Income Taxes [Line Items]
Allocation of federal benefits under tax sharing agreement					$ 64,000,000
Deferred income taxes and unamortized ITCs		$ 3,209,000,000	$ 3,031,000,000
Other		917,000,000	731,000,000
Other deferred debits and other assets		1,910,000,000	2,059,000,000
Separation from Parent
Income Taxes [Line Items]
Deferred income taxes and unamortized ITCs				$ 508,000,000
Other		336,000,000	168,000,000	11,000,000
Other deferred debits and other assets		178,000,000	362,000,000	497,000,000
Separation from Parent | Subsequent Event
Income Taxes [Line Items]
Other	$ 152,000,000
Separation from Parent | Affiliated Entities
Income Taxes [Line Items]
Payable for tax liabilities upon separation				103,000,000
Separation from Parent | Accounts Payable | Affiliated Entities
Income Taxes [Line Items]
Payable for tax liabilities upon separation				53,000,000
Separation from Parent | Other Noncurrent Liabilities | Affiliated Entities
Income Taxes [Line Items]
Payable for tax liabilities upon separation		37,000,000	50,000,000	$ 50,000,000
Separation from Parent | Other Receivables, Net, Current | Affiliated Entities
Income Taxes [Line Items]
Payable for tax liabilities upon separation		11,000,000	18,000,000
Separation from Parent | Accounts Payable and Accrued Liabilities | Affiliated Entities
Income Taxes [Line Items]
Payable for tax liabilities upon separation		$ 0	$ 0