v3.26.1
Derivatives and Hedge Accounting Activities (Schedule of Derivatives not Designated as Hedging Instruments) (Detail) - Derivatives Not Designated as Hedging Instruments - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] $ 187 $ 149 $ 115 $ 79
Virginia Electric and Power Company        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] 233 128 254 82
Commodity | Operating Revenue        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] (78) 23 (203) (16)
Commodity | Operating Revenue | Virginia Electric and Power Company        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] 0 (9) 0 (19)
Commodity | Purchased Gas        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] (3) 0 2 0
Commodity | Purchased Electric Capacity        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] 0 0 (7) (0)
Commodity | Purchased Electric Capacity | Virginia Electric and Power Company        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] (0) 0 (7) (0)
Commodity | Electric Fuel and Other Energy-Related Purchases        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] 231 139 275 105
Commodity | Electric Fuel and Other Energy-Related Purchases | Virginia Electric and Power Company        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] 233 137 261 101
Interest Rate Contract | Interest And Related Charges        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] $ 37 $ (13) $ 48 $ (10)
[1] Excludes amounts related to foreign currency exchange rate derivatives that are deferred to regulatory assets/liabilities that will begin to amortize as
the CVOW Commercial Project is placed in service.
[2] Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in the Companies’ Consolidated Statements of Income.