v3.26.1
Fair value measurements - Schedule of Investments Held by Plan that are Measured at Fair Value (Details) - EBP 005 - USD ($)
Dec. 31, 2025
Dec. 31, 2024
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value $ 250,449,827 $ 226,670,008
Investment held in master trust, recorded at fair value 263,382,548 236,067,272
Dominion Energy common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 111,817,928 109,004,669
Mutual Fund    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 0 682,212
Investment Excluding Common Collective Trust Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 111,817,928 109,686,881
Investment held in master trust, recorded at fair value 380,511,478 396,825,975
Short-term Securities    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment held in master trust, recorded at fair value 380,511,478 396,825,975
Master Trust    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment held in master trust, recorded at fair value 2,912,622,035 2,645,983,838
Level 1 | Dominion Energy common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 111,817,928 109,004,669
Level 1 | Mutual Fund    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 0 682,212
Level 1 | Investment Excluding Common Collective Trust Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 111,817,928 109,686,881
Investment held in master trust, recorded at fair value 0 0
Level 1 | Short-term Securities    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment held in master trust, recorded at fair value 0 0
Level 2 | Dominion Energy common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 0 0
Level 2 | Investment Excluding Common Collective Trust Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 0 0
Investment held in master trust, recorded at fair value 380,511,478 396,825,975
Level 2 | Short-term Securities    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment held in master trust, recorded at fair value 380,511,478 396,825,975
Level 3 | Dominion Energy common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 0 0
Level 3 | Investment Excluding Common Collective Trust Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 0 0
Investment held in master trust, recorded at fair value 0 0
Level 3 | Short-term Securities    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment held in master trust, recorded at fair value 0 0
Assets Recorded at NAV | Common/collective trust funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investment recorded at fair value 138,631,899 116,983,127
Investment held in master trust, recorded at fair value $ 2,532,110,557 $ 2,249,157,863