v3.25.2
Acquisitions and Dispositions - (Schedule of Results of Operations of Disposal Groups Reported As Discontinued Operations) (Parenthetical) (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]        
Income tax expense (benefit) $ (3) $ (14) $ (3) $ 40
East Ohio, PSNC and Questar Gas        
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]        
Income tax expense (benefit)   $ (4)   (73)
East Ohio | Enbridge        
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]        
Income tax expense (benefit) [1]       11
Employee benefit plans       45
Employee benefit plans after tax       $ 33
[1] Represents amounts attributable to Dominion Energy prior to the closing of the East Ohio Transaction which closed on March 6, 2024 and the Questar Gas Transaction which closed on May 31, 2024.