Regulatory Matters (Narrative) (Detail) $ in Millions	1 Months Ended												2 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2024 USD ($) MW	Sep. 30, 2024 USD ($)	Jul. 31, 2024 USD ($)	Jun. 30, 2024 USD ($) Bcf / d	May 31, 2024 USD ($)	Mar. 31, 2024 USD ($) mi kV	Feb. 29, 2024 USD ($)	Jan. 31, 2024 USD ($)	Nov. 30, 2023 USD ($)	Oct. 31, 2023 USD ($) Project MW	Jul. 31, 2023 USD ($)	May 31, 2023 USD ($)	Jun. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Maximum | Subsequent Event
Public Utilities General Disclosures [Line Items]
Capacity expenses expected to be incurred with PJM	$ 145
Virginia Regulation
Public Utilities General Disclosures [Line Items]
Percentage of earned return											9.04%
Authorized return percentage							9.35%				9.35%
Virginia Regulation | Annual Fuel Factor | Securitization Option
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement						$ 541
North Carolina Regulation
Public Utilities General Disclosures [Line Items]
Application date						2024-03
North Carolina Regulation | Rider DSM
Public Utilities General Disclosures [Line Items]
Increase (Decrease) in customer usage tracker						$ 31
North Carolina Regulation | Virginia Power Base Rate Case
Public Utilities General Disclosures [Line Items]
Increase(Decrease) in gas cost						$ 57
Percentage of earned return						5.01%
Percentage of proposed earned return						10.60%
Authorized return percentage						9.75%
North Carolina Regulation | Virginia Power Base Rate Case | Subsequent Event
Public Utilities General Disclosures [Line Items]
Increase(Decrease) in gas cost	$ 37
Authorized return percentage	9.95%
North Carolina Regulation | Virginia Power Fuel Filing | Subsequent Event
Public Utilities General Disclosures [Line Items]
Increase (Decrease) In fuel component of electric rates	$ 107
South Carolina Regulation
Public Utilities General Disclosures [Line Items]
Materials and supplies inventory write down														$ 50
Impairment of assets and other charges (benefits)														58
Impairment of assets and other charges (benefits) after tax														$ 44
South Carolina Regulation | Forecast
Public Utilities General Disclosures [Line Items]
One-time bill credit																	$ 7
South Carolina Regulation | Electric Base Rate Case
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement			$ 219
Approved return on equity percentage			9.94%
Percentage of earned return						4.32%
Percentage of proposed earned return						10.60%
Authorized return percentage						9.50%
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Estimated under-recovered balances							$ 1,300
Virginia Electric and Power Company | Impairment of Assets and Other Charges
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges (benefits)															$ (17)
Impairment of assets and other charges (benefits) after tax															(12)
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 | Utility Scale Solar
Public Utilities General Disclosures [Line Items]
Proposed cost of project										$ 850
Number of utility-scale projects | Project										4
Targeted capacity provided by legislation | MW										329
Virginia Electric and Power Company | Utility Scale Solar | Subsequent Event
Public Utilities General Disclosures [Line Items]
Proposed cost of project	$ 605
Targeted capacity provided by legislation | MW	208
Virginia Electric and Power Company | Virginia LNG Storage Facility
Public Utilities General Disclosures [Line Items]
Liquefied equivalent | Bcf / d				2
Regasify storage capacity				25.00%
Liquefy storage capacity				1.00%
Facility expected cost, excluding financing costs				$ 550
Virginia Electric and Power Company | Virginia Regulation
Public Utilities General Disclosures [Line Items]
Public utilities event costs to be recovered									$ 45
One-time credits to customers		$ 15
Authorized return percentage							9.70%				9.70%
Capitalization ratio											52.10%
Virginia Electric and Power Company | Virginia Regulation | Base Rate Case
Public Utilities General Disclosures [Line Items]
Total revenue requirement											$ 350
Virginia Electric and Power Company | Virginia Regulation | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Total revenue requirement					$ 2,200							$ 2,300
Rate year beginning					2024-07							2023-07
Increase (decrease) in revenue requirement					$ 636
Estimated under-recovered balances												$ 1,300
Estimated over-recovered balances													$ 266
Virginia Electric and Power Company | Virginia Regulation | Annual Fuel Factor | Securitization Option
Public Utilities General Disclosures [Line Items]
Estimated under-recovered balances												$ 1,300
Virginia Electric and Power Company | Virginia Regulation | Generation And Distribution Services
Public Utilities General Disclosures [Line Items]
Authorized return percentage									9.05%
Virginia Electric and Power Company | Biennial Review
Public Utilities General Disclosures [Line Items]
Authorized return percentage							0.70%
Dominion Energy South Carolina Inc | South Carolina Regulation | Electric DSM Programs
Public Utilities General Disclosures [Line Items]
Public energy efficiency programs cost rate adjustment approval request to recover amount								$ 47
Dominion Energy South Carolina Inc | South Carolina Regulation | Cost of Fuel
Public Utilities General Disclosures [Line Items]
Rate year beginning							2024-05
Application date							2024-02
Proposed increase (decrease) in annual base fuel component recoveries																$ (315)
Increase (decrease) in annual base fuel component recoveries						$ (316)
Dominion Energy South Carolina Inc | South Carolina Regulation | Electric Base Rate Case
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement		$ 291				295
Increase in proposed base rate percentage		12.59%
Increase (decrease) in net of storm damage						$ (4)
Dominion Energy South Carolina Inc | South Carolina Regulation | Electric Transmission Projects
Public Utilities General Disclosures [Line Items]
Application date						2024-03
Type of Line | kV						230
Miles of Lines | mi						7
Cost Estimate						$ 40									$ 40