Operating Segments (Schedule of Segment Reporting Information, by Segment) (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Operating Revenue		$ 3,794	$ 3,596	$ 9,046	$ 7,875
Net Income (Loss) from discontinued operations including noncontrolling interest	[1]	13	(1)	8	18
Net income (loss) attributable to Dominion Energy		599	(453)	1,596	258
Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		3,794	3,596	9,046	7,875
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		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		(251)	(231)	(505)	(471)
Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(251)	(231)	(505)	(471)
Dominion Energy Virginia
Segment Reporting Information [Line Items]
Operating Revenue		2,253	2,172	4,641	4,341
Dominion Energy Virginia | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		2,254	2,175	4,643	4,347
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		391	440	777	958
Dominion Energy Virginia | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		(1)	(3)	(2)	(6)
Gas Distribution
Segment Reporting Information [Line Items]
Operating Revenue		626	565	1,994	1,795
Gas Distribution | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		626	565	1,993	1,794
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		103	125	381	419
Gas Distribution | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		0	0	1	1
Dominion Energy South Carolina
Segment Reporting Information [Line Items]
Operating Revenue		773	815	1,618	1,614
Dominion Energy South Carolina | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		771	812	1,615	1,610
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		68	124	159	233
Dominion Energy South Carolina | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		2	3	3	4
Contracted Assets
Segment Reporting Information [Line Items]
Operating Revenue		132	167	443	416
Contracted Assets | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		127	161	435	406
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0	0	0
Net income (loss) attributable to Dominion Energy		11	20	167	121
Contracted Assets | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		5	6	8	10
Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenue		261	108	855	180
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		16	(117)	360	(282)
Net Income (Loss) from discontinued operations including noncontrolling interest		13	(1)	8	18
Net income (loss) attributable to Dominion Energy		26	(1,162)	112	(1,473)
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		$ 245	$ 225	$ 495	$ 462

[1] Includes income tax expense (benefit) of $4 million and $(2) million for the three months ended June 30, 2023 and 2022, respectively, and $3 million and $4 million for the six months ended June 30, 2023 and 2022, respectively.