Goodwill and Intangible Assets (Goodwill) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	$ 4,143	$ 4,253
Sale of Hope	[2]		(110)
Goodwill, Ending Balance	[1]	4,143	4,143
Operating Segments | Dominion Energy Virginia
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	2,106	2,106
Sale of Hope	[2]		0
Goodwill, Ending Balance	[1]	2,106	2,106
Operating Segments | Dominion Energy South Carolina
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	1,521	1,521
Sale of Hope	[2]		0
Goodwill, Ending Balance	[1]	1,521	1,521
Operating Segments | Contracted Energy
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	516	516
Sale of Hope	[2]		0
Goodwill, Ending Balance	[1]	516	516
Operating Segments | Corporate and Other
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	0	110
Sale of Hope	[2]		(110)
Goodwill, Ending Balance	[1]	$ 0	$ 0

[1] Goodwill amounts do not contain any accumulated impairment losses.

[2] See Note 3 for additional information.