Operating Segments (Schedule of Segment Reporting Information, by Segment, Virginia Power) (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) attributable to Dominion Energy		711	1,008
Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue	[1]	2,167	1,830
Net income (loss) attributable to Dominion Energy		357	374
Dominion Energy Virginia
Segment Reporting Information [Line Items]
Operating Revenue		2,169	1,985
Dominion Energy Virginia | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue		2,165	1,981
Net income (loss) attributable to Dominion Energy		516	432
Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenue		72	100
Corporate and Other | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue		2	(151)
Net income (loss) attributable to Dominion Energy		$ (159)	$ (58)

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