Acquisitions and Dispositions (Business Review Dispositions) (Narrative) (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022		Feb. 29, 2024	Sep. 30, 2023	Aug. 31, 2023
Business Acquisition And Dispositions [Line Items]
State			$ 60,000,000		$ 277,000,000		$ 59,000,000
Deferred taxes			(302,000,000)		1,474,000,000		58,000,000
Income tax expense (benefit)			308,000,000	[1]	568,000,000	[2]	$ 59,000,000	[3]
Impairment of goodwill			0
East Ohio | Enbridge
Business Acquisition And Dispositions [Line Items]
Disposal group, total value of consideration										$ 6,600,000,000
Disposal group, cash consideration										4,300,000,000
Disposal group, indebtedness										2,300,000,000
Disposal group, recognized a pre-tax gain (loss)			(97,000,000)
Disposal group, gain (loss) recorded after tax			(109,000,000)
Goodwill write-off			$ 1,500,000,000
Deferred taxes					29,000,000
Disposal group, transition services description			At the closing of the East Ohio Transaction, Dominion Energy and Enbridge entered into a transition services agreement pursuant to which Dominion Energy will continue to provide certain services to support the ongoing operations of East Ohio for up to approximately two years. Enbridge has also agreed to provide certain services to Dominion Energy.
Impairment of goodwill					50,000,000
Goodwill impairment after tax					45,000,000
PSNC | Enbridge
Business Acquisition And Dispositions [Line Items]
Disposal group, total value of consideration										3,300,000,000
Disposal group, cash consideration										2,000,000,000
Disposal group, indebtedness										1,300,000,000
Disposal group, recognized a pre-tax gain (loss)			$ (35,000,000)
Disposal group, gain (loss) recorded after tax			(31,000,000)
Goodwill write-off			700,000,000
Deferred taxes					334,000,000
Deferred tax of classified held for sale			$ 16,000,000
Disposal group, transition services description			At the closing of the PSNC Transaction, Dominion Energy and Enbridge entered into a transition services agreement pursuant to which Dominion Energy will continue to provide certain services to support the ongoing operations of PSNC for up to approximately two years. Enbridge has also agreed to provide certain services to Dominion Energy.
Questar Gas and Wexpro | Enbridge
Business Acquisition And Dispositions [Line Items]
Disposal group, total value of consideration										4,300,000,000
Disposal group, cash consideration										3,000,000,000
Disposal group, indebtedness										$ 1,300,000,000
Disposal group, recognized a pre-tax gain (loss)	$ 78,000,000		$ 2,000,000		236,000,000
Disposal group, gain (loss) recorded after tax	78,000,000		42,000,000		231,000,000
Goodwill write-off			$ 700,000,000
Deferred taxes	10,000,000				472,000,000
Income tax expense (benefit)	$ (5,000,000)
Disposal group, transition services description			At the closing of the Questar Gas Transaction, Dominion Energy and Enbridge entered into a transition services agreement pursuant to which Dominion Energy will continue to provide certain services to support the ongoing operations of Questar Gas and Wexpro for up to approximately two years. Enbridge has also agreed to provide certain services to Dominion Energy.
Impairment of goodwill					236,000,000
Goodwill impairment after tax					$ 231,000,000
Other Sales | Tredegar Solar Fund I, LLC
Business Acquisition And Dispositions [Line Items]
Disposal group, cash consideration											$ 21,000,000
Realizable fair value charge		$ 68,000,000
Realizable fair value charge net of tax		$ 51,000,000
Other Sales | Birdseye and Madison
Business Acquisition And Dispositions [Line Items]
Disposal group, cash consideration									$ 17,000,000

[1] The significant expense categories and amounts in the segment information presented above align with the segment-level information that is regularly provided to Dominion Energy’s CODM.

[2] The significant expense categories and amounts in the segment information presented above align with the segment-level information that is regularly provided to Dominion Energy’s CODM.

[3] The significant expense categories and amounts in the segment information presented above align with the segment-level information that is regularly provided to Dominion Energy’s CODM.