v3.26.3
Derivatives and Hedge Accounting Activities (Schedule of Offsetting Liabilities) (Detail) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] $ 418 $ 240
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 54 65
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 283 125
Net Amounts 81 50
Virginia Electric and Power Company    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 48 24
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 17 16
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 31 8
Commodity Contract | Over-the-counter    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 89 38
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 15 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 74 34
Commodity Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 39 6
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 15 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 24 2
Commodity Contract | Exchange    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 320 173
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 37 48
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 283 125
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] 0 19
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 0 5
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 0 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] 0 8
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 0 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral 0 0
Net Amounts 0 4
Foreign Currency Exchange Rate Contract | Over-the-counter    
Offsetting Liabilities [Line Items]    
Gross Liabilities Presented in the Consolidated Balance Sheet [1] 9 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 7 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] 9 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 $ 7 $ 2
[1] Excludes derivative liabilities of $6 million and $5 million at Dominion Energy and $7 million and $7 million at Virginia Power at September 30, 2026 and December 31, 2025, respectively, which are not subject to master netting or other similar arrangements.