Acquisitions and Dispositions - (Schedule of Results of Operations of Disposal Groups Reported As Discontinued Operations) (Detail) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2024		Jun. 30, 2023		Jun. 30, 2024		Jun. 30, 2023
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income tax expense (benefit)		$ (19)		$ 38		$ 32		$ 94
Net income (loss) attributable to Dominion Energy		81		168		195		449
East Ohio | Enbridge
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue				235		229	[1]	547
Operating expense				153		254	[1],[2]	369
Other income (expense)				7		(17)	[1]	15
Interest and related charges				17		15	[1]	32
Income (loss) before income taxes				72		(57)	[1]	161
Income tax expense (benefit)				6		9	[1]	19
Net income (loss) attributable to Dominion Energy				66	[3]	(66)	[1],[4]	142	[3]
PSNC | Enbridge
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue		109		120		407		446
Operating expense		63	[2]	98		221	[2]	306
Other income (expense)		3		3		6		5
Interest and related charges		14		12		28		25
Income (loss) before income taxes		35		13		164		120
Income tax expense (benefit)		22		2		53		26
Net income (loss) attributable to Dominion Energy		13	[4]	11	[3]	111	[4]	94	[3]
Questar Gas and Wexpro | Enbridge
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue		199	[1]	271		894	[1]	1,001
Operating expense		171	[1],[2]	233		746	[1],[2]	812
Other income (expense)		1	[1]	2		2	[1]	3
Interest and related charges		9	[1]	17		25	[1]	33
Income (loss) before income taxes		20	[1]	23		125	[1]	159
Income tax expense (benefit)		(36)	[1]	3		46	[1]	32
Net income (loss) attributable to Dominion Energy		56	[1],[4]	20	[3]	79	[1],[4]	127	[3]
Other Sales
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue		0				0
Operating expense	[2]	(9)				(8)
Other income (expense)		0				0
Interest and related charges		0				0
Income (loss) before income taxes		9				8
Income tax expense (benefit)		0				0
Net income (loss) attributable to Dominion Energy	[4]	$ 9				$ 8
Other Sales | Tredegar Solar Fund I, LLC
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue				2				3
Operating expense				19				22
Other income (expense)				0				0
Interest and related charges				1				1
Income (loss) before income taxes				(18)				(20)
Income tax expense (benefit)				(4)				(5)
Net income (loss) attributable to Dominion Energy	[3]			$ (14)				$ (15)

[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.

[2] East Ohio Transaction includes a charge of $45 million ($33 million after-tax) associated with an increase to certain pension retirement benefits attributable to a plan amendment and a contribution to the defined contribution employee savings plan. See Note 20 for further information on these transactions.

[3] Excludes $5 million and $(4) million of income tax expense (benefit) attributable to consolidated state and interim period tax allocation adjustments for the three and six months ended June 30, 2023, respectively.

[4] Excludes $(4) million and $(73) million of income tax expense (benefit) attributable to consolidated state adjustments for the three and six months ended June 30, 2024, respectively.