Regulatory Matters (Narrative) (Detail) $ in Millions	1 Months Ended						3 Months Ended	6 Months Ended	12 Months Ended
	May 31, 2023 USD ($)	Apr. 30, 2023 USD ($)	Mar. 31, 2023 USD ($) Project Components mi kV	Feb. 28, 2023 USD ($)	Jan. 31, 2023 USD ($)	Oct. 31, 2022 USD ($) MW	Mar. 31, 2023 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)		Dec. 31, 2011	Dec. 31, 2008
Public Utilities General Disclosures [Line Items]
Regulatory liabilities			$ 651				$ 651		$ 946	[1]
North Carolina Regulation | Public Service Company Of North Carolina
Public Utilities General Disclosures [Line Items]
Application date							2023-03
North Carolina Regulation | Public Service Company Of North Carolina | Rider D
Public Utilities General Disclosures [Line Items]
Increase(Decrease) in gas cost				$ (56)
Approval date				2023-03
North Carolina Regulation | Public Service Company Of North Carolina | Rider DSM
Public Utilities General Disclosures [Line Items]
Increase (Decrease) in customer usage tracker			23
Ohio Regulation | PIR Program
Public Utilities General Disclosures [Line Items]
Application date							2023-02
Percentage of pipeline system replaced												25.00%
Total gross plant investment estimated cost									225
Proposed revenue requirement									305
Cumulative gross plant investment estimated cost									2,400
Ohio Regulation | CEP Program
Public Utilities General Disclosures [Line Items]
Application date							2023-03
Total gross plant investment estimated cost									195
Proposed revenue requirement									1,300
Cumulative gross plant investment estimated cost									151
Percentage of debt rate on capital investments											6.50%
Ohio Regulation | Subsequent Event [Member] | PIR Program
Public Utilities General Disclosures [Line Items]
Increases of annual capital expenditures percentage		3.00%
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Regulatory liabilities			309				$ 309		$ 506	[2]
Virginia Electric and Power Company | Annual Fuel Factor | Forecast
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement	$ (13)
Virginia Electric and Power Company | Utility Scale Solar
Public Utilities General Disclosures [Line Items]
Proposed cost of project						$ 1,200
Targeted capacity provided by legislation | MW						474
Virginia Electric and Power Company | Energy Storage
Public Utilities General Disclosures [Line Items]
Targeted capacity provided by legislation | MW						16
Virginia Electric and Power Company | Electric Distribution Grid Transformation Projects
Public Utilities General Disclosures [Line Items]
Proposed cost of project			1,100				1,100
Proposed operations and maintenance investment			$ 71
Number of electric distribution grid transformation projects | Project			14
Number of electric distribution grid transformation projects components | Components			6
Virginia Electric and Power Company | Virginia Regulation | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement							(541)
Estimated under-recovered balances								$ 578
Public utilities collection of requested under-recovered projected fuel expense period								3 years
Virginia Electric and Power Company | Virginia Regulation | Annual Fuel Factor | Forecast
Public Utilities General Disclosures [Line Items]
Total revenue requirement	$ 2,300
Rate year beginning	2023-07
Increase (decrease) in revenue requirement	$ 631
Fuel cost requirement	3,300
Estimated under-recovered balances	$ 1,300
Virginia Electric and Power Company | Virginia Regulation | Subsequent Event [Member]
Public Utilities General Disclosures [Line Items]
Authorized return percentage		9.70%
Authorized return percentage credited to customers bills		100.00%
Capitalization ratio		52.10%
Virginia Electric and Power Company | Virginia Regulation | Subsequent Event [Member] | Base Rate Case
Public Utilities General Disclosures [Line Items]
Total revenue requirement		$ 350
Virginia Electric and Power Company | Biennial Review | Subsequent Event [Member]
Public Utilities General Disclosures [Line Items]
Authorized return percentage		9.35%
Credited to customers bills percentage		85.00%
Virginia Electric and Power Company | Triennial Review | Subsequent Event [Member]
Public Utilities General Disclosures [Line Items]
Credited to customers bills percentage		85.00%
Dominion Energy South Carolina Inc | South Carolina Regulation | Electric Other
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement				$ 24
Dominion Energy South Carolina Inc | South Carolina Regulation | Rider DSM
Public Utilities General Disclosures [Line Items]
Annual transportation cost rate adjustment, approval amount requested to recover amount					$ 46
Dominion Energy South Carolina Inc | South Carolina Regulation | Cost Of Fuel
Public Utilities General Disclosures [Line Items]
Increase (decrease) in annual base fuel component recoveries							121
Dominion Energy South Carolina Inc | South Carolina Regulation | Electric Transmission Project
Public Utilities General Disclosures [Line Items]
Application date			2023-03
Type of Line | kV			230
Miles of Lines | mi			19
Cost Estimate			$ 55				$ 55
Dominion Energy South Carolina Inc | South Carolina Regulation | Subsequent Event [Member] | Cost Of Fuel
Public Utilities General Disclosures [Line Items]
Increase (decrease) in annual base fuel component recoveries		$ 176
Dominion Energy South Carolina Inc | South Carolina Regulation | Subsequent Event [Member] | Natural Gas Base Rate Member
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement		$ 19
Percentage of earned return		10.38%
Authorized return percentage		10.25%
Questar Gas Company | Utah Regulation
Public Utilities General Disclosures [Line Items]
Increase(Decrease) in gas cost			$ 92	$ 164
Approval date				2023-02

[1] Dominion Energy’s Consolidated Balance Sheet at December 31, 2022 has been derived from the audited Consolidated Balance Sheet at that date.

[2] Virginia Power’s Consolidated Balance Sheet at December 31, 2022 has been derived from the audited Consolidated Balance Sheet at that date.