Operating Revenue (Schedule of Operating Revenue) (Parenthetical) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		$ 4,547	$ 3,840
Other revenues	[1],[2]	(268)	30
GT&S Transaction
Public Utilities General Disclosures [Line Items]
Revenue associated with discontinued operations			1
NGL Midstream | Transferred at a Point in Time
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		11	7
Renewable Energy Investment Tax Credits
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		4	6
Alternative Revenue Programs
Public Utilities General Disclosures [Line Items]
Other revenues		30	22
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		2,196	1,807
Other revenues	[1],[3]	(29)	23
Virginia Electric and Power Company | Renewable Energy Investment Tax Credits
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers			4
Virginia Electric and Power Company | Alternative Revenue Programs
Public Utilities General Disclosures [Line Items]
Other revenues		8	$ 20
Virginia Electric and Power Company | Maximum | Renewable Energy Investment Tax Credits
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		$ 1

[1] Includes alternative revenue of $30 million and $22 million at Dominion Energy and $8 million and $20 million at Virginia Power for the three months ended March 31, 2022 and 2021, respectively.

[2] Includes revenue associated with services provided to discontinued operations of $1 million for the three months ended March 31, 2021.

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