Acquisitions and Dispositions (Schedule of Results of Operations of Disposal Groups Reported As Discontinued Operations) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021		Dec. 31, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income tax expense (benefit)		$ 8	$ 188		$ (204)
Net income (loss) including noncontrolling interests	[1],[2]	9	641		(1,878)
Net income (loss) attributable to Dominion Energy		$ 9	641		(1,984)
GT&S Transaction
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue			5		4
Income tax expense (benefit)			(17)
Disposition of GTS Operations | Q-Pipe Group
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue			254	[3]	246
Operating expense	[4]		76	[3]	96
Other income	[5]		28	[3]	1
Interest and related charges	[6]		25	[3]	20
Income before income taxes			181	[3]	131
Income tax expense (benefit)	[7]		36	[3]	(9)
Net income (loss) including noncontrolling interests			145	[3]	140
Net income (loss) attributable to Dominion Energy			$ 145	[3]	140
Disposition of GTS Operations | GT&S Transaction
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue	[3]				1,710
Operating expense	[3],[4]				1,289
Other income	[3],[5]				88
Interest and related charges	[3],[6]				372
Income before income taxes	[3]				137
Income tax expense (benefit)	[3],[7]				334
Net income (loss) including noncontrolling interests	[3]				(197)
Noncontrolling interests	[3]				106
Net income (loss) attributable to Dominion Energy	[3]				$ (303)

[1] Includes income tax expense (benefit) of $8 million, $188 million and $(204) million for the years ended December 31, 2022, 2021 and 2020, respectively.

[2] See Note 9 for amounts attributable to related parties.

[3] Operations associated with the Q-Pipe Group are through the December 31, 2021 closing date. Operations associated with the GT&S Transaction are through the November 1, 2020 closing date.

[4] T&S Transaction includes a charge of $482 million ($359 million after-tax) recorded in 2020 associated with the probable abandonment of a significant portion of the Supply Header Project as well as the establishment of a $75 million ARO as a result of the cancellation of the Atlantic Coast Pipeline Project.

[5] Q-Pipe Group includes a $25 million benefit associated with the termination of the Q-Pipe Transaction in 2021.

[6] GT&S Transaction includes a loss of $237 million ($178 million after-tax) recorded in 2020 associated with cash flow hedges of debt-related items that were determined to be probable of not occurring.

[7] Excludes $17 million income tax benefit recorded in 2021 associated with the GT&S Transaction.