Operating Segments (Schedule of Segment Reporting Information, by Segment) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Operating Revenue	[1]	$ 4,496	$ 3,858
Net income (loss)		(270)	(680)
Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue	[2]	1,930	1,965
Net income (loss)		(280)	20
Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Operating Revenue	[3]	556	566
Net income (loss)		169	190
Net Income from discontinued operations			54
Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		(341)	(334)
Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		4,496	3,858
Adjustments&Eliminations
Segment Reporting Information [Line Items]
Operating Revenue			(33)
Eliminations
Segment Reporting Information [Line Items]
Operating Revenue		(341)	(367)
Dominion Energy Virginia
Segment Reporting Information [Line Items]
Operating Revenue		1,938	2,001
Net income (loss)		429	361
Dominion Energy Virginia | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue		1,930	1,994
Net income (loss)		427	358
Dominion Energy Virginia | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		(3)	(4)
Dominion Energy Virginia | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		1,935	1,997
Gas, Transmission & Storage
Segment Reporting Information [Line Items]
Operating Revenue		644	984
Net income (loss)		221	222
Gas, Transmission & Storage | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Operating Revenue		556	566
Net income (loss)		174	138
Net Income from discontinued operations			0
Gas, Transmission & Storage | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		57	54
Gas, Transmission & Storage | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		701	1,038
Distribution
Segment Reporting Information [Line Items]
Operating Revenue		887	917
Net income (loss)		225	205
Distribution | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		3	4
Distribution | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		890	921
Dominion Energy South Carolina
Segment Reporting Information [Line Items]
Operating Revenue		713	689
Net income (loss)		94	71
Dominion Energy South Carolina | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		1
Dominion Energy South Carolina | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		714	689
Contracted Generation
Segment Reporting Information [Line Items]
Operating Revenue		286	352
Net income (loss)		59	102
Contracted Generation | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		4	3
Contracted Generation | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		290	355
Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenue		28	(1,052)
Net income (loss)		(1,298)	(1,641)
Corporate and Other | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Operating Revenue		0	(29)
Net income (loss)		(707)	(338)
Corporate and Other | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Operating Revenue		0	0
Net income (loss)		(5)	52
Net Income from discontinued operations			54
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue		279	277
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue		$ 307	$ (775)

[1] See Note 10 for amounts attributable to related parties.

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

[3] See Note 19 for amounts attributable to related parties.