Operating Revenue (Schedule of Operating Revenue) (Parenthetical) (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		$ 4,655	$ 3,434	$ 12,996	$ 10,358
Other revenues	[1],[2]	(269)	(258)	(735)	(274)
GT&S Transaction
Public Utilities General Disclosures [Line Items]
Revenue associated with discontinued operations			1		3
NGL Midstream | Transferred at a Point in Time
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		10	9	35	24
Renewable Energy Investment Tax Credits
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		21	16	32	29
Alternative Revenue Programs
Public Utilities General Disclosures [Line Items]
Other revenues		20	3	90	50
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		2,959	1,987	7,394	5,517
Other revenues	[1],[3]	(84)	(11)	(177)	30
Virginia Electric and Power Company | Renewable Energy Investment Tax Credits
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		13	13	13	22
Virginia Electric and Power Company | Alternative Revenue Programs
Public Utilities General Disclosures [Line Items]
Other revenues		$ 20	$ 3	$ 47	$ 41

[1] Includes alternative revenue of $20 million and $3 million at Dominion Energy and $20 million and $3 million at Virginia Power for the three months ended September 30, 2022 and 2021, respectively, and $90 million and $50 million at Dominion Energy and $47 million and $41 million at Virginia Power for the nine months ended September 30, 2022 and 2021, respectively.

[2] Includes revenue associated with services provided to discontinued operations of $1 million and $3 million for the three and nine months ended September 30, 2021, respectively.

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