v3.25.2
Operating Segments - Virginia Power (Narrative) (Detail) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Segment Reporting Information [Line Items]    
Gain (loss) on investments $ 173 $ 395
Virginia Electric and Power Company    
Segment Reporting Information [Line Items]    
Gain (loss) on investments 24 52
Operating Segments    
Segment Reporting Information [Line Items]    
After- tax net benefits (expenses) (7) 19
Gain (loss) on investments 156 348
Gain (loss) on investments, after tax $ 87 $ 216
Investment, Type [Extensible Enumeration] Nuclear Decommissioning Trust Fund [Member] Nuclear Decommissioning Trust Fund [Member]
Operating Segments | Corporate and Other    
Segment Reporting Information [Line Items]    
After- tax net benefits (expenses) $ (102) $ (314)
After- tax net benefits (expenses) for specific items (27) (86)
Operating Segments | Virginia Electric and Power Company    
Segment Reporting Information [Line Items]    
Loss associated with severe weather events 106  
Loss associated with severe weather events, after-tax 79  
Share of costs not expected to be recovered from customers on the CVOW commercial project 48  
Share of costs not expected to be recovered from customers on the CVOW commercial project, after tax 36  
Gain (loss) on investments 23 46
Gain (loss) on investments, after tax $ 13 $ 29
Investment, Type [Extensible Enumeration] Nuclear Decommissioning Trust Fund [Member] Nuclear Decommissioning Trust Fund [Member]
Operating Segments | Virginia Electric and Power Company | Corporate and Other    
Segment Reporting Information [Line Items]    
After- tax net benefits (expenses) $ (90) $ 29
After- tax net benefits (expenses) for specific items $ (100) $ 29