Acquisitions and Dispositions - (Schedule of Results of Operations of Disposal Groups Reported As Discontinued Operations) (Parenthetical) (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2024		Mar. 31, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax expense (benefit)		$ 51		$ 56
Impairment of assets and other charges		30		98
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)		(69)		(9)
East Ohio | Enbridge
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax expense (benefit)		$ 9	[1]	$ 13
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.