Operating Segments (Schedule of Segment Reporting Information, by Segment, Virginia Power) (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) attributable to Dominion Energy		163	778	1,759	1,036
Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue	[1]	2,645	2,875	7,280	7,217
Net income (loss) attributable to Dominion Energy		473	571	1,158	975
Dominion Energy Virginia | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue		2,645	2,865	7,280	7,200
Net income (loss) attributable to Dominion Energy		532	618	1,308	1,576
Corporate and Other | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue		0	10	0	17
Net income (loss) attributable to Dominion Energy		$ (59)	$ (47)	$ (150)	$ (601)

[1] See Note 19 for amounts attributable to affiliates.