Regulatory Matters (Narrative) (Detail) $ / shares in Units, $ in Millions	1 Months Ended						3 Months Ended
	Mar. 31, 2025 USD ($) MW	Feb. 28, 2025	Jan. 31, 2025 USD ($)	Dec. 31, 2024 USD ($) mi kV	Oct. 31, 2024 USD ($) MW	Apr. 30, 2020	Mar. 31, 2025 USD ($)	Mar. 31, 2024 USD ($)	Apr. 30, 2025 USD ($) $ / shares
Targeted To Reach By End Of Year Five [Member]
Public Utilities General Disclosures [Line Items]
Energy efficiency target percentage. based on energy savings from 2019 baseline						5.00%
Virginia Regulation | 2025 Biennial Review
Public Utilities General Disclosures [Line Items]
Approved base rate increase effective January 2026	$ 458
Approved base rate increase effective January 2027	$ 173
Percentage of earned return	7.77%
Authorized return percentage	9.70%
Base rate increase effective January 2026	$ 822
Base rate increase effective January 2027	$ 345
Proposed base rates reflect an ROE	52.10%
Common equity capitalization to total capitalization ratio	10.40%
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Percentage of energy savings target for 2026		3.00%
Percentage of energy savings target for 2027		4.00%
Percentage of energy savings target for 2028		5.00%
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 | Utility Scale Solar
Public Utilities General Disclosures [Line Items]
Proposed cost of project					$ 605
Targeted capacity provided by legislation | MW					208
Virginia Electric and Power Company | Chesterfield Energy Reliability Center
Public Utilities General Disclosures [Line Items]
Proposed cost of project	$ 1,500						$ 1,500
Targeted capacity provided by legislation | MW	944
Virginia Electric and Power Company | Virginia Regulation | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Total revenue requirement	$ 2,600
Rate year beginning	2024-07
Increase (decrease) in revenue requirement	$ 860
Estimated under-recovered balances	205
Purchased capacity expense	$ 120
Virginia Electric and Power Company | Subsequent Event
Public Utilities General Disclosures [Line Items]
Common stock shares authorized but unissued shares									$ 3,500
Common stock par value | $ / shares									$ 0
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			$ 46
Dominion Energy South Carolina Inc | South Carolina Regulation | Cost of Fuel
Public Utilities General Disclosures [Line Items]
Rate year beginning		2025-05
Application date		2025-02
Proposed increase (decrease) in annual base fuel component recoveries							$ 154
Dominion Energy South Carolina Inc | South Carolina Regulation | Electric Transmission Projects
Public Utilities General Disclosures [Line Items]
Application date				2024-12
Type of Line | kV				230
Miles of Lines | mi				17
Cost Estimate				$ 55