v3.25.2
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, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] $ 149 $ (71) $ 79 $ (245)
Virginia Electric and Power Company        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] 128 (6) 82 (111)
Commodity | Operating Revenue        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] 23 (15) (16) 61
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] (9) 35 (19) 76
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] 139 (42) 105 (190)
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] 137 (41) 101 (187)
Commodity | Discontinued operations        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] 0 (1) 0 (25)
Interest Rate Contract | Interest And Related Charges        
Derivative Instruments Gain Loss [Line Items]        
Amount of Gain (Loss) Recognized in Income on Derivatives [1],[2] $ (13) $ (13) $ (10) $ (91)
[1] Excludes amounts related to foreign currency exchange rate derivatives that are deferred to plant under construction within property, plant and equipment and regulatory assets/liabilities that will begin to amortize once 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.