Income Taxes (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Income Taxes (Narrative) (Detail) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Taxes [Line Items]
Income tax benefit	$ 3	$ 35	$ 36	$ 68
Dominion Energy South Carolina, Inc. [Member]
Income Taxes [Line Items]
Income tax benefit			$ (14)

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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+ Details

DOMINION ENERGY SOUTH CAROLINA, INC. 10-Q