Acquisitions and Dispositions (Schedule of Capital Expenditures and Significant Noncash Items Reported As Discontinued Operations) (Detail) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021
Significant noncash items:
Accrued capital expenditures	[1]	$ 745	$ 374
Dominion Energy Gas Holdings, LLC | Q-Pipe Group
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Capital expenditures			26
Significant noncash items:
Accrued capital expenditures			$ 2

[1] See Note 10 for noncash investing activities related to the acquisition of a noncontrolling interest in Dominion Privatization and Notes 16 and 17 for noncash financing activities related to the remarketing of Series A Preferred Stock and the issuance of common stock and transfer of property associated with the settlement of litigation.