Investments (Narrative) (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023		Feb. 29, 2024
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investees					$ 3
Net earnings (losses) from discontinued operations including noncontrolling interest	[1]	$ (81)	$ (168)	$ (195)	(449)
Distributions received from investment				134	185
Equity method affiliates includes cash and accrued amounts of contributions				4	48
Current liabilities		1,830		1,830		$ 8,885	[2]
Contributions to equity method affiliates				8	48
Income tax expense (benefit) from discontinued operations		(19)	38	32	94
Investment company received distribution amount								$ 126
Discontinued operations
Schedule of Equity Method Investments [Line Items]
Net earnings (losses) from discontinued operations including noncontrolling interest				(11)	184
Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investees		(1)	18	(12)	17
Contributions to equity method affiliates					41
Atlantic Coast Pipeline | Other Current Liabilities
Schedule of Equity Method Investments [Line Items]
Current liabilities		13		13		4
Cove Point
Schedule of Equity Method Investments [Line Items]
Distributions received from investment			95		178
Discontinued operations, interest income			(11)
Discontinued operations, interest expense					51
Income tax expense (benefit) from discontinued operations			21		24
Cove Point | Discontinued operations
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investees			$ 90		$ 166
Finite Lived Equity Method Investment Basis Difference
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment that exceeded share of underlying equity		12		12		18
Equity method investment goodwill		9		9		9
Capitalized interest				(2)		(3)
Trading Securities
Schedule of Equity Method Investments [Line Items]
Rabbi trust securities		$ 145		145		$ 119
Maximum
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investees				$ 1

[1] Includes income tax expense (benefit) of $(19) million and $38 million for the three months ended June 30, 2024 and 2023, respectively, and $32 million and $94 million for the six months ended June 30, 2024 and 2023, respectively.

[2] Dominion Energy’s Consolidated Balance Sheet at December 31, 2023 has been derived from the audited Consolidated Balance Sheet at that date.