v3.26.1
Derivatives and Hedge Accounting Activities (Schedule of Offsetting Liabilities) (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] $ 455 $ 240
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 94 65
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 246 125
Net Amounts 115 50
Virginia Electric and Power Company    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 106 24
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 45 16
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 61 8
Commodity Contract | Over-the-counter    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 91 38
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 34 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 57 34
Commodity Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 38 6
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 34 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 4 2
Commodity Contract | Exchange    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 295 173
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 49 48
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 246 125
Net Amounts 0 0
Commodity Contract | Exchange | Virginia Electric and Power Company    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 0 0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 0 0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 0 0
Interest Rate Contract | Over-the-counter    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 61 19
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 9 5
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 52 14
Interest Rate Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 60 8
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 9 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 51 4
Foreign Currency Exchange Rate Contract | Over-the-counter    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 8 10
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 2 8
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 6 2
Foreign Currency Exchange Rate Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 8 10
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 2 8
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts $ 6 $ 2
[1] Excludes derivative liabilities of $6 million and $5 million at Dominion Energy and $5 million and $7 million at Virginia Power at June 30, 2026 and December 31, 2025, respectively, which are not subject to master netting or other similar arrangements.