v3.26.3
Fair Value Measurements (Assets and Liabilities that are Measured at Fair Value on a Recurring Basis) (Detail) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets $ 1,410 $ 958
Derivative Liabilities 424 245
Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 641 482
Derivative Liabilities 55 31
Fair Value, Measurements, Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 9,463 7,889
Total liabilities 424 245
Fair Value, Measurements, Recurring | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 4,854 4,064
Total liabilities 55 31
Fair Value, Measurements, Recurring | Equity securities: | U.S.    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 6,996 6,215
Fair Value, Measurements, Recurring | Equity securities: | U.S. | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 3,584 3,154
Fair Value, Measurements, Recurring | Equity securities: | International    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 187 168
Fair Value, Measurements, Recurring | Equity securities: | International | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 100 96
Fair Value, Measurements, Recurring | Fixed Income | Corporate debt instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 135 10
Fair Value, Measurements, Recurring | Fixed Income | Corporate debt instruments | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 124 0
Fair Value, Measurements, Recurring | Fixed Income | Government Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 369 492
Fair Value, Measurements, Recurring | Fixed Income | Government Securities | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 228 332
Fair Value, Measurements, Recurring | Private Debt Funds - Liquid Investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 313  
Fair Value, Measurements, Recurring | Private Debt Funds - Liquid Investments | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 177  
Fair Value, Measurements, Recurring | Cash equivalents and other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 53 46
Fair Value, Measurements, Recurring | Cash equivalents and other | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Foreign Currency Exchange Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 2 28
Derivative Liabilities 9 10
Fair Value, Measurements, Recurring | Foreign Currency Exchange Rate | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 2 28
Derivative Liabilities 9 10
Fair Value, Measurements, Recurring | Commodity    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 861 729
Derivative Liabilities 415 216
Fair Value, Measurements, Recurring | Commodity | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 159 257
Derivative Liabilities 46 13
Fair Value, Measurements, Recurring | Interest Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 547 201
Derivative Liabilities 0 19
Fair Value, Measurements, Recurring | Interest Rate | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 480 197
Derivative Liabilities 0 8
Fair Value, Measurements, Recurring | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 7,383 6,847
Total liabilities 0 0
Fair Value, Measurements, Recurring | Level 1 | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 3,787 3,582
Total liabilities 0 0
Fair Value, Measurements, Recurring | Level 1 | Equity securities: | U.S.    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 6,996 6,215
Fair Value, Measurements, Recurring | Level 1 | Equity securities: | U.S. | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 3,584 3,154
Fair Value, Measurements, Recurring | Level 1 | Equity securities: | International    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 187 168
Fair Value, Measurements, Recurring | Level 1 | Equity securities: | International | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 100 96
Fair Value, Measurements, Recurring | Level 1 | Fixed Income | Corporate debt instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 1 | Fixed Income | Corporate debt instruments | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 1 | Fixed Income | Government Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 146 418
Fair Value, Measurements, Recurring | Level 1 | Fixed Income | Government Securities | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 102 332
Fair Value, Measurements, Recurring | Level 1 | Private Debt Funds - Liquid Investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0  
Fair Value, Measurements, Recurring | Level 1 | Private Debt Funds - Liquid Investments | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0  
Fair Value, Measurements, Recurring | Level 1 | Cash equivalents and other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 53 46
Fair Value, Measurements, Recurring | Level 1 | Cash equivalents and other | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 1 | Foreign Currency Exchange Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 0 0
Derivative Liabilities 0 0
Fair Value, Measurements, Recurring | Level 1 | Foreign Currency Exchange Rate | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 0 0
Derivative Liabilities 0 0
Fair Value, Measurements, Recurring | Level 1 | Commodity    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 1 0
Derivative Liabilities 0 0
Fair Value, Measurements, Recurring | Level 1 | Commodity | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 1 0
Derivative Liabilities 0 0
Fair Value, Measurements, Recurring | Level 1 | Interest Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 0 0
Derivative Liabilities 0 0
Fair Value, Measurements, Recurring | Level 1 | Interest Rate | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 0 0
Derivative Liabilities 0 0
Fair Value, Measurements, Recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 1,327 400
Total liabilities 300 230
Fair Value, Measurements, Recurring | Level 2 | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 979 274
Total liabilities 22 31
Fair Value, Measurements, Recurring | Level 2 | Equity securities: | U.S.    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 2 | Equity securities: | U.S. | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 2 | Equity securities: | International    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 2 | Equity securities: | International | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 2 | Fixed Income | Corporate debt instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 135 10
Fair Value, Measurements, Recurring | Level 2 | Fixed Income | Corporate debt instruments | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 124 0
Fair Value, Measurements, Recurring | Level 2 | Fixed Income | Government Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 223 74
Fair Value, Measurements, Recurring | Level 2 | Fixed Income | Government Securities | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 126 0
Fair Value, Measurements, Recurring | Level 2 | Private Debt Funds - Liquid Investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 313  
Fair Value, Measurements, Recurring | Level 2 | Private Debt Funds - Liquid Investments | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 177  
Fair Value, Measurements, Recurring | Level 2 | Cash equivalents and other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 2 | Cash equivalents and other | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 2 | Foreign Currency Exchange Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 2 28
Derivative Liabilities 9 10
Fair Value, Measurements, Recurring | Level 2 | Foreign Currency Exchange Rate | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 2 28
Derivative Liabilities 9 10
Fair Value, Measurements, Recurring | Level 2 | Commodity    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 107 87
Derivative Liabilities 291 201
Fair Value, Measurements, Recurring | Level 2 | Commodity | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 70 49
Derivative Liabilities 13 13
Fair Value, Measurements, Recurring | Level 2 | Interest Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 547 201
Derivative Liabilities 0 19
Fair Value, Measurements, Recurring | Level 2 | Interest Rate | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 480 197
Derivative Liabilities 0 8
Fair Value, Measurements, Recurring | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 753 642
Total liabilities 124 15
Fair Value, Measurements, Recurring | Level 3 | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 88 208
Total liabilities 33 0
Fair Value, Measurements, Recurring | Level 3 | Equity securities: | U.S.    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Equity securities: | U.S. | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Equity securities: | International    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Equity securities: | International | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Fixed Income | Corporate debt instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Fixed Income | Corporate debt instruments | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Fixed Income | Government Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Fixed Income | Government Securities | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Private Debt Funds - Liquid Investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0  
Fair Value, Measurements, Recurring | Level 3 | Private Debt Funds - Liquid Investments | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0  
Fair Value, Measurements, Recurring | Level 3 | Cash equivalents and other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Cash equivalents and other | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments [1] 0 0
Fair Value, Measurements, Recurring | Level 3 | Foreign Currency Exchange Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 0 0
Derivative Liabilities 0 0
Fair Value, Measurements, Recurring | Level 3 | Foreign Currency Exchange Rate | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 0 0
Derivative Liabilities 0 0
Fair Value, Measurements, Recurring | Level 3 | Commodity    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 753 642
Derivative Liabilities 124 15
Fair Value, Measurements, Recurring | Level 3 | Commodity | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 88 208
Derivative Liabilities 33 0
Fair Value, Measurements, Recurring | Level 3 | Interest Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 0 0
Derivative Liabilities 0 0
Fair Value, Measurements, Recurring | Level 3 | Interest Rate | Virginia Electric and Power Company    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives Assets 0 0
Derivative Liabilities $ 0 $ 0
[1] Includes investments held in the nuclear decommissioning trusts and rabbi trusts. Excludes $2.1 billion and $2.3 billion for Dominion Energy, inclusive of $1.1 billion and $1.3 billion at Virginia Power, at September 30, 2026 and December 31, 2025, respectively, of assets measured at fair value using NAV (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy.