Operating Segments (Schedule of Segment Reporting Information, by Segment) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Operating Revenue		$ 4,279	$ 3,870
Net Income (Loss) from discontinued operations including noncontrolling interest	[1]	19	28
Net income (loss) attributable to Dominion Energy		711	1,008
Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		4,279	3,869
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		0	17
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	1
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(240)	(251)
Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(240)	(234)
Dominion Energy Virginia
Segment Reporting Information [Line Items]
Operating Revenue		2,169	1,985
Dominion Energy Virginia | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		2,172	1,987
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0
Net income (loss) attributable to Dominion Energy		518	434
Dominion Energy Virginia | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		(3)	(2)
Gas Distribution
Segment Reporting Information [Line Items]
Operating Revenue		1,230	976
Gas Distribution | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		1,229	975
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0
Net income (loss) attributable to Dominion Energy		294	251
Gas Distribution | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		1	1
Dominion Energy South Carolina
Segment Reporting Information [Line Items]
Operating Revenue		799	754
Dominion Energy South Carolina | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		798	752
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0
Net income (loss) attributable to Dominion Energy		109	102
Dominion Energy South Carolina | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		1	2
Contracted Assets
Segment Reporting Information [Line Items]
Operating Revenue		249	289
Contracted Assets | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		245	268
Net Income (Loss) from discontinued operations including noncontrolling interest		0	0
Net income (loss) attributable to Dominion Energy		101	150
Contracted Assets | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		4	21
Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenue		72	100
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		(165)	(130)
Net Income (Loss) from discontinued operations including noncontrolling interest		19	28
Net income (loss) attributable to Dominion Energy		(311)	71
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		$ 237	$ 230

[1] Includes income tax expense of $6 million and $7 million for the three months ended March 31, 2022 and 2021, respectively.