Investments (Narrative) (Detail 2) - USD ($)		1 Months Ended				3 Months Ended			12 Months Ended
		Jul. 31, 2023	Feb. 28, 2022	Dec. 31, 2021	Oct. 31, 2017	Dec. 31, 2022		Mar. 31, 2022	Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Feb. 29, 2024	Sep. 30, 2023	Jun. 30, 2021	Jul. 31, 2020	Sep. 30, 2014
Schedule of Equity Method Investments [Line Items]
Earnings (losses) from equity method investees									$ (26,000,000)		$ 21,000,000		$ 15,000,000
Distributions received from investment									245,000,000		355,000,000		332,000,000
Noncurrent Assets Held for Sale						$ 18,831,000,000					18,831,000,000
Income tax expense (benefit) from discontinued operations									1,300,000,000		197,000,000		374,000,000
Contributions to equity method affiliates									104,000,000		43,000,000		1,021,000,000
Current liabilities						1,403,000,000			8,885,000,000		1,403,000,000
Facility Limit		$ 600,000,000				6,000,000,000	[1]		6,000,000,000	[1]	6,000,000,000	[1]
Goodwill write-off	[2]										110,000,000
Income tax expense				$ 173,000,000					575,000,000		113,000,000		(181,000,000)
Impairment of certain property, plant and equipment									(307,000,000)		(1,401,000,000)		(194,000,000)
Scenario, Forecast
Schedule of Equity Method Investments [Line Items]
Investment company received distribution amount																$ 126,000,000
364 Term loan facility
Schedule of Equity Method Investments [Line Items]
Credit facility, outstanding amount		2,200,000,000
364 Term Loan Facility One
Schedule of Equity Method Investments [Line Items]
Credit facility, outstanding amount		750,000,000
Revolving Credit Facility
Schedule of Equity Method Investments [Line Items]
Facility Limit																		$ 6,000,000,000
GT&S Transaction
Schedule of Equity Method Investments [Line Items]
Income tax expense (benefit) from discontinued operations													$ 19,000,000
Cove Point
Schedule of Equity Method Investments [Line Items]
Noncurrent Assets Held for Sale						2,700,000,000					$ 2,700,000,000
Wrangler Retail Gas Holdings LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage of limited partner interests													20.00%	20.00%	20.00%
Limited partnership interest sale transaction, proceeds received													$ 127,000,000
Initial fair value				$ 23,000,000									23,000,000
Amount of gain from sale													87,000,000
Goodwill write-off													14,000,000
Income tax expense													$ 32,000,000
Wrangler Retail Gas Holdings LLC | Gas Supply, Inc.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage of limited partner interests											15.00%		5.00%
Cash consideration from sale of noncontrolling interest											$ 85,000,000
Amount of gain from sale											11,000,000		$ 10,000,000
Amount of gain from sale, after tax											8,000,000
Income tax expense													3,000,000
Sale of interest in Cove Point													33,000,000
Dominion Energy Virginia
Schedule of Equity Method Investments [Line Items]
Cash consideration from sale of noncontrolling interest			$ 120,000,000								215,000,000
Limited partnership interest sale transaction, proceeds received			$ 60,000,000			$ 108,000,000					$ 108,000,000
Percentage ownership in total units			50.00%			50.00%					50.00%
Initial fair value			$ 60,000,000			$ 107,000,000					$ 107,000,000
Amount of gain from sale						133,000,000		$ 23,000,000
Amount of gain from sale, after tax						$ 99,000,000		$ 16,000,000
Agreement entered date			2022-02
Cove Point
Schedule of Equity Method Investments [Line Items]
Distributions received from investment									227,000,000		344,000,000		300,000,000
Income tax expense (benefit) from discontinued operations									$ 31,000,000		92,000,000		60,000,000
Percentage of noncontrolling limited partnership interest retained	[3]								50.00%
Discontinued operations, interest income											(160,000,000)
Discontinued operations, interest expense									$ 120,000,000				12,000,000
Cove Point | Discontinued Operations
Schedule of Equity Method Investments [Line Items]
Earnings (losses) from equity method investees									218,000,000		$ 277,000,000		259,000,000
Cove Point | GT&S Transaction
Schedule of Equity Method Investments [Line Items]
Percentage of noncontrolling limited partnership interest retained						50.00%					50.00%
Cove Point | Cove Point | GT&S Transaction
Schedule of Equity Method Investments [Line Items]
Percentage of noncontrolling limited partnership interest retained																	50.00%
Cove Point | BHE | GT&S Transaction
Schedule of Equity Method Investments [Line Items]
Cash consideration from sale of noncontrolling interest		$ 3,300,000,000
Percentage of noncontrolling limited partnership interest retained		50.00%
Amount of gain from sale		$ 626,000,000
Amount of gain from sale, after tax		348,000,000
Proceeds from settlement of related interest rate derivatives, fair value		$ 199,000,000
Cove Point | East Ohio, PSNC and Questar Gas | GT&S Transaction
Schedule of Equity Method Investments [Line Items]
Percentage of noncontrolling limited partnership interest retained																	50.00%
Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Earnings (losses) from equity method investees									$ 15,000,000		$ (7,000,000)		(20,000,000)
Percentage of noncontrolling limited partnership interest retained									53.00%
Contributions to equity method affiliates									$ 95,000,000		3,000,000		965,000,000
Equity in earnings (losses) on investments after tax									11,000,000		(5,000,000)		$ (14,000,000)
Atlantic Coast Pipeline | Revolving Credit Facility
Schedule of Equity Method Investments [Line Items]
Facility Limit					$ 3,400,000,000														$ 1,900,000,000
Credit facility, maturity date					Oct. 31, 2021
Atlantic Coast Pipeline | Other Current Liabilities
Schedule of Equity Method Investments [Line Items]
Current liabilities						$ 114,000,000			$ 4,000,000		$ 114,000,000
Atlantic Coast Pipeline | Dominion Energy Gas Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage acquired																				5.00%
Percentage ownership in total units																				53.00%
Align RNG, LLC
Schedule of Equity Method Investments [Line Items]
Percentage of noncontrolling limited partnership interest retained									50.00%
Impairment of certain property, plant and equipment									$ (35,000,000)
Asset impairment charges after tax									$ 26,000,000

[1] This credit facility matures in June 2026, with the potential to be extended by the borrowers to June 2028, and can be used by the borrowers under the credit facility to support bank borrowings and the issuance of commercial paper, as well as to support up to a combined $2.0 billion of letters of credit.

[2] See Note 3 for additional information.

[3] Dominion Energy’s sold its remaining 50% noncontrolling limited partnership interest in September 2023. See discussion below. Presented in noncurrent assets held for sale in Dominion Energy’s Consolidated Balance Sheets at December 31, 2022.