Regulatory Matters (Narrative) (Detail) shares in Millions, $ in Millions		1 Months Ended												2 Months Ended	3 Months Ended				6 Months Ended		9 Months Ended		12 Months Ended
	Nov. 08, 2023 USD ($)	Oct. 31, 2023 USD ($) MW	Sep. 30, 2023 USD ($)	Jul. 31, 2023 USD ($) shares	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	Jun. 30, 2022 USD ($)	May 31, 2022 USD ($)	Mar. 31, 2022	Nov. 30, 2023 shares	Sep. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) Battery	Sep. 30, 2022 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2022 USD ($)		Dec. 31, 2011	Dec. 31, 2008
Public Utilities General Disclosures [Line Items]
Depreciation and amortization															$ 663		$ 630				$ 1,884	$ 1,832
Regulatory liabilities			$ 434												434						$ 434			$ 748	[1]
Base Rate Case | Subsequent Event
Public Utilities General Disclosures [Line Items]
Percentage of proposed earned return		10.40%
Generation And Distribution Services
Public Utilities General Disclosures [Line Items]
Authorized return percentage				9.70%
Virginia Regulation
Public Utilities General Disclosures [Line Items]
Percentage of earned return				9.04%
Authorized return percentage				9.35%
North Carolina Regulation
Public Utilities General Disclosures [Line Items]
Application date							2023-03
North Carolina Regulation | Rider D
Public Utilities General Disclosures [Line Items]
Increase(Decrease) in gas cost								$ (56)
Approval date								2023-03
North Carolina Regulation | Rider DSM
Public Utilities General Disclosures [Line Items]
Increase (Decrease) in customer usage tracker			34				$ 23
Ohio Regulation | PIR Program
Public Utilities General Disclosures [Line Items]
Application date																					2023-04
Percentage of pipeline system replaced																											25.00%
Increases of annual capital expenditures percentage						3.00%
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																					2023-09
Total gross plant investment estimated cost			195												195						$ 195
Proposed revenue requirement																					1,300
Cumulative gross plant investment estimated cost			151												151						151
Percentage of debt rate on capital investments																										6.50%
Ohio Regulation | Base Rate Case | Subsequent Event
Public Utilities General Disclosures [Line Items]
Increase (Decrease) in non-fuel base rate		$ 212
Authorized return percentage		10.38%
Ohio Regulation | UEX Rider
Public Utilities General Disclosures [Line Items]
Public utilities, under-recovered accumulated bad debt expense																$ 9
Actual revenue requirement																					23
Ohio Regulation | UEX Rider | Forecast
Public Utilities General Disclosures [Line Items]
Recovery of bad debt expense																							$ 14
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Authorized but unissued shares of common stock | shares				3,250
Depreciation and amortization															488		451				1,367	$ 1,305
Regulatory liabilities			226												226						226			$ 506	[2]
Virginia Electric and Power Company | Subsequent Event
Public Utilities General Disclosures [Line Items]
Authorized but unissued shares of common stock | shares														3,250
Virginia Electric and Power Company | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement					$ (13)
Virginia Electric and Power Company | Annual Fuel Factor | Impairment of Assets and Other Charges
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																		$ 191
Virginia Electric and Power Company | Rider RGGI | Impairment of Assets and Other Charges
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																		180
Virginia Electric and Power Company | Income Payment Program | Subsequent Event
Public Utilities General Disclosures [Line Items]
Universal service fee		$ 71
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 | Utility Scale Solar | Subsequent Event
Public Utilities General Disclosures [Line Items]
Proposed cost of project		$ 850
Targeted capacity provided by legislation | MW		329
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			773				1,100								773	1,100					$ 773
Proposed operations and maintenance investment			71				$ 71
Number of electric distribution grid transformation projects | Project							14
Number of electric distribution grid transformation projects components | Components							6
Number of battery energy storage system | Battery																					5
Proposed capital cost of energy storage system			50												$ 50						$ 50
Batteries to be installed over number of years																					5 years
Virginia Electric and Power Company | Virginia Regulation
Public Utilities General Disclosures [Line Items]
Rate year beginning					2023-07
Authorized return percentage				9.70%		9.70%
Authorized return percentage credited to customers bills						100.00%
Capitalization ratio				52.10%		52.10%
Estimated under-recovered balances																			$ 1,300
Virginia Electric and Power Company | Virginia Regulation | Subsequent Event
Public Utilities General Disclosures [Line Items]
Capitalization ratio														52.10%
Estimated under-recovered balances	$ 1,300
Virginia Electric and Power Company | Virginia Regulation | Base Rate Case
Public Utilities General Disclosures [Line Items]
Total revenue requirement				$ 350	$ 351	$ 350
Virginia Electric and Power Company | Virginia Regulation | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Total revenue requirement					$ 2,300							$ 2,300
Rate year beginning					2023-07							2022-07
Increase (decrease) in revenue requirement					$ 631																$ (541)
Fuel cost requirement					3,300
Impairment of assets and other charges after tax																		142
Estimated under-recovered balances					$ 1,300						$ 1,000									$ 578
Public utilities collection of requested under-recovered projected fuel expense period																				3 years
Virginia Electric and Power Company | Virginia Regulation | Rider RGGI
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges after tax																		$ 134
Depreciation and amortization																	33
Depreciation and amortization after tax																	$ 25
Virginia Electric and Power Company | Biennial Review
Public Utilities General Disclosures [Line Items]
Authorized return percentage				0.70%		9.35%
Credited to customers bills percentage						85.00%
Authorized return percentage credited to customers bills						1.50%
Virginia Electric and Power Company | Triennial Review
Public Utilities General Disclosures [Line Items]
Authorized return percentage						0.70%
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]
Approval request to recover costs and net lost revenues 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						$ 176	$ 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 | Natural Gas Base Rate Case
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement			$ 9				$ 19
Percentage of proposed earned return							10.38%
Authorized return percentage			9.49%										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 and recast for certain events as discussed in Note 1.

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