v3.25.2
Fair Value Measurements (Financial Instruments' Carrying Amounts and Fair Values) (Detail) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Carrying Amount    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt [1],[2] $ 37,954 $ 34,533
Securitization bonds [2],[3] 1,136 1,217
Junior subordinated notes [1],[2] 3,223 3,223
Estimate of Fair Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt [1] 36,145 32,167
Securitization bonds [3] 1,152 1,218
Junior subordinated notes [1] 3,417 3,372
Virginia Electric and Power Company | Carrying Amount    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt [1] 20,114 19,224
Securitization bonds [3] 1,136 1,217
Virginia Electric and Power Company | Estimate of Fair Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt [1],[2] 18,711 17,578
Securitization bonds [2],[3] $ 1,152 $ 1,218
[1] Carrying amount includes current portions included in securities due within one year and amounts which represent the unamortized debt issuance costs and discount or premium. There were no fair value hedges associated with fixed-rate debt at June 30, 2025 and December 31, 2024.
[2] Fair value is estimated using market prices, where available, and interest rates currently available for issuance of debt with similar terms and remaining maturities. All fair value measurements are classified as Level 2. The carrying amount of debt issuances with short-term maturities and variable rates refinanced at current market rates is a reasonable estimate of their fair value.
[3] Carrying amount includes current portions included in securities due within one year.