v3.26.1
Related-Party Transactions (Narrative) (Detail) - USD ($)
 1 Months Ended 3 Months Ended 6 Months Ended
Sep. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Related Party Transaction [Line Items]            
Borrowing Interest Charges   $ 14,000,000 $ 22,000,000 $ 25,000,000 $ 36,000,000  
Virginia Electric and Power Company            
Related Party Transaction [Line Items]            
Affiliated current borrowings   1,398,000,000   1,398,000,000   $ 1,173,000,000 [1]
Outstanding borrowings, net of repayments, under money pool for non-regulated subsidiaries   $ 0   0   0
Lease agreement maturity period   15 years        
Other deferred charges and other assets of right-of-use asset   $ 273,000,000   273,000,000    
Virginia Electric and Power Company | Affiliated Entity            
Related Party Transaction [Line Items]            
Derivative assets   11,000,000   11,000,000   22,000,000
Derivative liabilities   10,000,000   10,000,000   12,000,000
Affiliated lease payables   213,000,000   213,000,000   188,000,000
Lease agreement maturity period 20 months          
Other deferred charges and other assets of right-of-use asset   210,000,000   210,000,000   185,000,000
Virginia Electric and Power Company | Affiliated Entity | CVOW Commercial Project            
Related Party Transaction [Line Items]            
Capitalized affiliates lease cost   36,000,000   72,000,000    
Virginia Electric and Power Company | Affiliated Entity | Other Current Liabilities            
Related Party Transaction [Line Items]            
Affiliated lease payables   140,000,000   140,000,000   141,000,000
Virginia Electric and Power Company | Affiliated Entity | Other Deferred Credits and Other Liabilities            
Related Party Transaction [Line Items]            
Affiliated lease payables   73,000,000   73,000,000   47,000,000
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   658,000,000   658,000,000   594,000,000
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   759,000,000   759,000,000   729,000,000
Virginia Electric and Power Company | Principal Owner | Short-Term Borrowing Arrangements            
Related Party Transaction [Line Items]            
Affiliated current borrowings   $ 1,400,000,000   $ 1,400,000,000   $ 1,200,000,000
[1] Virginia Power’s Consolidated Balance Sheet at December 31, 2025 has been derived from the audited Consolidated Balance Sheet at that date.