Acquisitions and Dispositions - (Schedule of Results of Operations of Disposal Groups Reported As Discontinued Operations) (Detail) - USD ($) $ in Millions	3 Months Ended
	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
Net income (loss) attributable to Dominion Energy	114		281
East Ohio | Enbridge
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue	229	[1]	312
Operating expense	254	[1],[2]	216
Other income (expense)	(17)	[1]	8
Interest and related charges	15	[1]	15
Income (loss) before income taxes	(57)	[1]	89
Income tax expense (benefit)	9	[1]	13
Net income (loss) attributable to Dominion Energy	(66)	[1],[3]	76	[4]
PSNC | Enbridge
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue	298		326
Operating expense	158	[2]	208
Other income (expense)	3		2
Interest and related charges	14		13
Income (loss) before income taxes	129		107
Income tax expense (benefit)	31		(24)
Net income (loss) attributable to Dominion Energy	98	[3]	83	[4]
Questar Gas and Wexpro | Enbridge
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue	695		730
Operating expense	575	[2]	579
Other income (expense)	1		1
Interest and related charges	16		16
Income (loss) before income taxes	105		136
Income tax expense (benefit)	82		29
Net income (loss) attributable to Dominion Energy	23	[3]	107	[4]
Other Sales | Tredegar Solar Fund I, LLC
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating revenue	0		1
Operating expense	1	[2]	3
Income (loss) before income taxes	(1)		(2)
Income tax expense (benefit)	0		(1)
Net income (loss) attributable to Dominion Energy	$ (1)	[3]	$ (1)	[4]

[1] Represents amounts attributable to Dominion Energy prior to the closing of the East Ohio Transaction which closed on March 6, 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 $(69) million of income tax expense (benefit) attributable to consolidated state adjustments for the three months ended March 31, 2024.

[4] Excludes $(9) million of income tax expense (benefit) attributable to consolidated state and interim period tax allocation adjustments for three months ended March 31, 2023.