Operating Segments (Schedule of Segment Reporting Information, by Segment) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Operating Revenue		$ 5,252	$ 4,279
Net Income (Loss) from discontinued operations including noncontrolling interest	[1]	(5)	19
Net income (loss) attributable to Dominion Energy		997	711
Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		5,252	4,279
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		0	0
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0
Net income (loss) attributable to Dominion Energy		0	0
Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		0	0
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(254)	(240)
Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(254)	(240)
Dominion Energy Virginia
Segment Reporting Information [Line Items]
Operating Revenue		2,388	2,169
Dominion Energy Virginia | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		2,389	2,172
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0
Net income (loss) attributable to Dominion Energy		386	518
Dominion Energy Virginia | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		(1)	(3)
Gas Distribution
Segment Reporting Information [Line Items]
Operating Revenue		1,368	1,230
Gas Distribution | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		1,367	1,229
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0
Net income (loss) attributable to Dominion Energy		278	294
Gas Distribution | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		1	1
Dominion Energy South Carolina
Segment Reporting Information [Line Items]
Operating Revenue		845	799
Dominion Energy South Carolina | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		844	798
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0
Net income (loss) attributable to Dominion Energy		91	109
Dominion Energy South Carolina | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		1	1
Contracted Assets
Segment Reporting Information [Line Items]
Operating Revenue		311	249
Contracted Assets | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		308	245
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0
Net income (loss) attributable to Dominion Energy		156	101
Contracted Assets | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		3	4
Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenue		594	72
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		344	(165)
Net Income (Loss) from discontinued operations including noncontrolling interest		(5)	19
Net income (loss) attributable to Dominion Energy		86	(311)
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		$ 250	$ 237

[1] Includes income tax expense (benefit) of $(1) million and $6 million for the three months ended three months ended March 31, 2023 and 2022, respectively.