Acquisitions and Dispositions (Business Review Dispositions) (Narrative) (Detail) - USD ($) $ in Millions	1 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2023	Aug. 31, 2023	Sep. 30, 2023	Sep. 30, 2023
East Ohio | Enbridge
Business Acquisition And Dispositions [Line Items]
Disposal group, total value of consideration	$ 6,600		$ 6,600	$ 6,600
Disposal group, cash consideration	4,300		4,300	4,300
Disposal group, indebtedness	2,300		2,300	2,300
Termination fee	155		155	$ 155
Disposal group, recognized a pre-tax gain (loss)	20
Disposal group, gain (loss) recorded after tax	(20)
Goodwill write-off	1,500
Deferred taxes			30
Disposal group, transition services description				At the closing of the East Ohio Transaction, Dominion Energy and Enbridge will enter 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.
PSNC | Enbridge
Business Acquisition And Dispositions [Line Items]
Disposal group, total value of consideration	3,100		3,100	$ 3,100
Disposal group, cash consideration	2,200		2,200	2,200
Disposal group, indebtedness	1,000		1,000	1,000
Termination fee	78		78	$ 78
Disposal group, recognized a pre-tax gain (loss)	130
Disposal group, gain (loss) recorded after tax	(290)
Goodwill write-off	700
Deferred taxes			385
Disposal group, transition services description				At the closing of the PSNC Transaction, Dominion Energy and Enbridge will enter 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		4,300	$ 4,300
Disposal group, cash consideration	3,000		3,000	3,000
Disposal group, indebtedness	1,300		1,300	1,300
Termination fee	107		107	$ 107
Disposal group, recognized a pre-tax gain (loss)	(10)
Disposal group, gain (loss) recorded after tax	(530)
Goodwill write-off	$ 1,000
Deferred taxes			$ 524
Disposal group, transition services description				At the closing of the Questar Gas Transaction, Dominion Energy and Enbridge will enter 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.
Other Sales | Tredegar Solar Fund I, LLC
Business Acquisition And Dispositions [Line Items]
Disposal group, cash consideration		$ 21
Gain (loss) on held for sale		(1)
Gain (loss) on held for sale, after tax		$ 1