Related-Party Transactions (Narrative) (Detail) - USD ($)		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Related Party Transaction [Line Items]
Amounts due to Dominion, noncurrent		$ 1,774,000,000		$ 1,774,000,000		$ 1,755,000,000	[1]
Borrowing Interest Charges		5,000,000	$ 21,000,000	6,000,000	$ 45,000,000
Virginia Electric and Power Company
Related Party Transaction [Line Items]
Amounts due to Dominion, noncurrent	[2]	1,085,000,000		1,085,000,000		1,125,000,000	[3]
Payable to affiliates		1,505,000,000		1,505,000,000		500,000,000	[3]
Outstanding borrowings, net of repayments, under money pool for non-regulated subsidiaries		$ 0		$ 0		$ 0
Issuance of stock (in shares)		0	0	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		$ 16,000,000		$ 16,000,000		$ 1,000,000
Derivative liabilities		51,000,000		51,000,000		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		480,000,000		480,000,000		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		621,000,000		621,000,000		584,000,000
Virginia Electric and Power Company | Principal Owner | Short-Term Borrowing Arrangements
Related Party Transaction [Line Items]
Payable to affiliates		$ 1,500,000,000		$ 1,500,000,000		$ 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 19 for amounts attributable to affiliates.

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