Goodwill and Intangible Assets (Goodwill) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	$ 7,405	$ 7,381
Acquisition	[2]		24
Sale of Hope	[2]	(110)
Goodwill, Ending Balance	[1]	7,295	7,405
Operating Segments | Dominion Energy Virginia
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	2,106	2,106
Goodwill, Ending Balance	[1]	2,106	2,106
Operating Segments | Gas Distribution
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	3,512	3,512
Sale of Hope	[2]	(110)
Goodwill, Ending Balance	[1]	3,402	3,512
Operating Segments | Dominion Energy South Carolina
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	1,521	1,521
Goodwill, Ending Balance	[1]	1,521	1,521
Operating Segments | Contracted Assets
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	266	242
Acquisition	[2]		24
Goodwill, Ending Balance	[1]	$ 266	$ 266

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

[2] See Note 3 for more information.