Operating Segments (Schedule of Segment Reporting Information, by Segment, Virginia Power) (Detail) - USD ($) $ in Millions			1 Months Ended	12 Months Ended
		Nov. 30, 2020	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating Revenue				$ 13,964	$ 14,172	$ 14,401
Depreciation, depletion and amortization				2,478	2,332	2,283
Interest income				101	107	97
Interest and related charges				1,354	1,377	1,486
Income tax expense		$ 336	$ 173	425	83	209
Net income (loss)				3,288	(401)	1,358
Capital expenditures				6,061	6,331	5,321
Total assets			99,590	99,590	95,905
Dominion Energy Virginia
Segment Reporting Information [Line Items]
Operating Revenue				7,999	7,787	8,157
Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenue				184	1,163	832
Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue	[1]			7,470	7,763	8,108
Depreciation, depletion and amortization				1,364	1,252	1,223
Interest income				11	11	11
Interest and related charges	[1]			534	516	524
Income tax expense				397	229	264
Net income (loss)				1,712	1,021	1,149
Capital expenditures				3,756	3,372	2,981
Total assets			47,932	47,932	43,654
Virginia Electric and Power Company | Dominion Energy Virginia
Segment Reporting Information [Line Items]
Operating Revenue				7,976	7,763	8,137
Depreciation, depletion and amortization				1,296	1,245	1,215
Interest income				11	11	11
Interest and related charges				535	524	529
Income tax expense				467	500	481
Net income (loss)				1,914	1,884	1,783
Capital expenditures				3,756	3,372	2,981
Total assets			47,900	47,900	43,700
Virginia Electric and Power Company | Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenue				(506)	0	(29)
Depreciation, depletion and amortization				68	7	8
Interest income				0	0	0
Interest and related charges				(1)	(8)	(5)
Income tax expense				(70)	(271)	(217)
Net income (loss)				(202)	(863)	(634)
Capital expenditures				0	0	$ 0
Total assets			$ 0	$ 0	$ 0

[1] See Note 25 for amounts attributable to affiliates.