Operating Segments (Schedule of Segment Reporting Information, by Segment) (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Operating Revenue		$ 3,810	$ 3,963	$ 10,859	$ 10,135
Net Income (Loss) from discontinued operations including noncontrolling interest	[1]	(554)	152	(105)	775
Net income (loss) attributable to Dominion Energy		163	778	1,759	1,036
Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		3,810	3,963	10,859	10,135
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Total revenue from external customers		0	0	0	0
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		0	0	0	0
Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		0	0	0	0
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(234)	(208)	(704)	(634)
Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(234)	(208)	(704)	(634)
Dominion Energy Virginia | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		2,649	2,870	7,285	7,212
Operating Revenue		2,645	2,865	7,280	7,200
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		532	618	1,308	1,576
Dominion Energy Virginia | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		(4)	(5)	(5)	(12)
Dominion Energy South Carolina | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		944	915	2,559	2,525
Operating Revenue		945	917	2,563	2,531
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		143	175	302	408
Dominion Energy South Carolina | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		1	2	4	6
Contracted Energy | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		226	240	660	645
Operating Revenue		232	245	674	660
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		54	65	123	95
Contracted Energy | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		6	5	14	15
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		(9)	(62)	355	(247)
Operating Revenue		222	144	1,046	378
Net Income (Loss) from discontinued operations including noncontrolling interest		(554)	152	(105)	775
Net income (loss) attributable to Dominion Energy		(566)	(80)	26	(1,043)
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		$ 231	$ 206	$ 691	$ 625

[1] Includes income tax expense of $1.2 billion and $53 million for the three months ended September 30, 2023 and 2022, respectively, and $1.3 billion and $185 million for the nine months ended September 30, 2023 and 2022, respectively.