Related-Party Transactions (Narrative) (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Related Party Transaction [Line Items]
Borrowing Interest Charges	$ 14,000,000
Dividend paid	569,000,000	$ 559,000,000
Maximum
Related Party Transaction [Line Items]
Borrowing Interest Charges		$ 1,000,000
Virginia Electric and Power Company
Related Party Transaction [Line Items]
Affiliated current borrowings	1,675,000,000		$ 500,000,000	[1]
Outstanding borrowings, net of repayments, under money pool for non-regulated subsidiaries	$ 0		0
Issuance of stock (in shares)	0	0
Dividend declared			407,000,000
Dividend paid	$ 407,000,000
Virginia Electric and Power Company | Affiliated Entity
Related Party Transaction [Line Items]
Derivative assets	30,000,000		19,000,000
Derivative liabilities	3,000,000		17,000,000
Virginia Electric and Power Company | Affiliated Entity | Pension Benefits | Amounts Associated With Dominion Pension Plan
Related Party Transaction [Line Items]
Other deferred credits and other liabilities	527,000,000		505,000,000
Virginia Electric and Power Company | Affiliated Entity | Medical Coverage for Local retirees | Amounts Associated with the Dominion Retiree Health and Welfare Plan
Related Party Transaction [Line Items]
Amounts due from Dominion, noncurrent	675,000,000		663,000,000
Virginia Electric and Power Company | Principal Owner | Short-Term Borrowing Arrangements
Related Party Transaction [Line Items]
Affiliated current borrowings	$ 1,700,000,000		$ 500,000,000

[1] Virginia Power’s Consolidated Balance Sheet at December 31, 2024 has been derived from the audited Consolidated Balance Sheet at that date.