v3.25.2
Derivatives and Hedge Accounting Activities (Selected Information Related to Gains (Losses) on Cash Flow Hedges Included in AOCI) (Detail)
$ in Millions
6 Months Ended
Jun. 30, 2025
USD ($)
Derivative Instruments Gain Loss [Line Items]  
AOCI After-Tax $ (172)
Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax (27)
Virginia Electric and Power Company  
Derivative Instruments Gain Loss [Line Items]  
AOCI After-Tax 23
Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax 1
Interest Rate Contract  
Derivative Instruments Gain Loss [Line Items]  
AOCI After-Tax (172)
Interest rate, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax $ (27)
Maximum Term 390 months
Interest Rate Contract | Virginia Electric and Power Company  
Derivative Instruments Gain Loss [Line Items]  
AOCI After-Tax $ 23
Interest rate, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax $ 1
Maximum Term 390 months