Related-Party Transactions (Narrative) (Detail) - USD ($)		3 Months Ended		12 Months Ended
		Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Related Party Transaction [Line Items]
Amounts due to Dominion, noncurrent		$ 7,549,000,000		$ 7,396,000,000	[1]
Payable to affiliates	[2]	2,093,000,000		2,078,000,000	[1]
Borrowing Interest Charges			$ 24,000,000
Maximum
Related Party Transaction [Line Items]
Borrowing Interest Charges		1,000,000
Virginia Electric and Power Company
Related Party Transaction [Line Items]
Amounts due to Dominion, noncurrent	[3]	5,524,000,000		5,401,000,000	[4]
Payable to affiliates	[3]	1,437,000,000		1,529,000,000	[4]
Outstanding borrowings, net of repayments, under money pool for non-regulated subsidiaries		$ 0		$ 0
Issuance of stock (in shares)		0	0
Commencing Period				20 months
Lease commencement term				2025-08
Related party transaction costs				$ 240,000,000
Cost of Revenue, Related Party, Type [Extensible Enumeration]				Affiliated Entity
Virginia Electric and Power Company | Affiliated Entity
Related Party Transaction [Line Items]
Derivative assets		$ 4,000,000		$ 1,000,000
Derivative liabilities		59,000,000		79,000,000
Virginia Electric and Power Company | Affiliated Entity | Pension Benefits | Amounts Associated With Dominion Pension Plan
Related Party Transaction [Line Items]
Amounts due to Dominion, noncurrent		468,000,000		456,000,000
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		602,000,000		584,000,000
Virginia Electric and Power Company | Principal Owner | Short-Term Borrowing Arrangements
Related Party Transaction [Line Items]
Payable to affiliates		$ 1,000,000		$ 500,000,000

[1] Dominion Energy’s Consolidated Balance Sheet at December 31, 2023 has been derived from the audited Consolidated Balance Sheet at that date.

[2] See Note 10 for amounts attributable to related parties.

[3] See Note 19 for amounts attributable to affiliates.

[4] Virginia Power’s Consolidated Balance Sheet at December 31, 2023 has been derived from the audited Consolidated Balance Sheet at that date.