v3.26.3
Derivatives and Hedge Accounting Activities (Schedule of Offsetting Assets) (Detail) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] $ 1,060 $ 741
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 54 65
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 1,006 676
Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 632 464
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 17 16
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 615 448
Commodity Contract | Over-the-counter    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 473 464
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 15 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 458 460
Commodity Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 149 239
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 15 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 134 235
Commodity Contract | Exchange    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 38 48
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 37 48
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 1 0
Commodity Contract | Exchange | Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 1 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 Received 0 0
Net Amounts 1 0
Interest Rate Contract | Over-the-counter    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 547 201
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 0 5
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 547 196
Interest Rate Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 480 197
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 0 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 480 193
Foreign Currency Exchange Rate Contract | Over-the-counter    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 2 28
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 2 8
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 0 20
Foreign Currency Exchange Rate Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 2 28
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 2 8
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts $ 0 $ 20
[1] Excludes derivative assets of $350 million and $217 million at Dominion Energy and $9 million and $18 million at Virginia Power at September 30, 2026 and December 31, 2025, respectively, which are not subject to master netting or other similar arrangements.