Operating Segments (Schedule of Segment Reporting Information, by Segment) (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Operating Revenue		$ 3,596	$ 3,038	$ 7,875	$ 6,908
Net Income (Loss) from discontinued operations including noncontrolling interest	[1]	(1)	26	18	54
Net income (loss) attributable to Dominion Energy		(453)	285	258	1,293
Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		3,596	3,037	7,875	6,906
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		0	11	0	28
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	1	0	2
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(231)	(250)	(471)	(501)
Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(231)	(239)	(471)	(473)
Dominion Energy Virginia
Segment Reporting Information [Line Items]
Operating Revenue		2,172	1,747	4,341	3,732
Dominion Energy Virginia | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		2,175	1,752	4,347	3,739
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		440	431	958	865
Dominion Energy Virginia | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		(3)	(5)	(6)	(7)
Gas Distribution
Segment Reporting Information [Line Items]
Operating Revenue		565	455	1,795	1,431
Gas Distribution | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		565	453	1,794	1,428
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		125	95	419	346
Gas Distribution | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		0	2	1	3
Dominion Energy South Carolina
Segment Reporting Information [Line Items]
Operating Revenue		815	681	1,614	1,435
Dominion Energy South Carolina | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		812	679	1,610	1,431
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		124	84	233	186
Dominion Energy South Carolina | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		3	2	4	4
Contracted Assets
Segment Reporting Information [Line Items]
Operating Revenue		167	274	416	563
Contracted Assets | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		161	257	406	525
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		20	104	121	254
Contracted Assets | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		6	17	10	38
Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenue		108	120	180	220
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		(117)	(115)	(282)	(245)
Net Income (Loss) from discontinued operations including noncontrolling interest		(1)	26	18	54
Net income (loss) attributable to Dominion Energy		(1,162)	(429)	(1,473)	(358)
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		$ 225	$ 235	$ 462	$ 465

[1] Includes income tax expense (benefit) of $(2) million and $4 million for the three months ended June 30, 2022 and 2021, respectively, and $4 million and $11 million for the six months ended June 30, 2022 and 2021, respectively.