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Debt instrument maturity month and year.

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Disposal group including discontinued operation cash consideration.

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Disposal group, including discontinued operation, deposits.

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Disposal group including discontinued operation gain (loss) on disposal.

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Disposal group including discontinued operation gain (loss) on disposal after tax.

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Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

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Description of the facts and circumstances leading to the completed or expected disposal, and the manner and timing of that disposal.

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Amount of revenue attributable to disposal group, including, but not limited to, discontinued operation.

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Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Acquisitions and Dispositions (Disposition of Gas Transmission & Storage Operations) (Narrative) (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jul. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Oct. 31, 2021	Nov. 30, 2020	Oct. 31, 2020	Jul. 31, 2020
Business Acquisition And Dispositions [Line Items]
Credit facility, amount borrowed		$ 900		$ 900
Term Loan Credit Agreement
Business Acquisition And Dispositions [Line Items]
Credit facility, amount borrowed	$ 1,300
Credit facility, description				The agreement matures in December 2021, which can be extended at Dominion Energy’s option to June 2022, and bears interest at a variable rate.
Debt, maturity month and year	2021-12
GT&S Transaction
Business Acquisition And Dispositions [Line Items]
Operating revenue		1	$ 1	$ 3	$ 4
GT&S Transaction \| BHE
Business Acquisition And Dispositions [Line Items]
Disposal group, total value of consideration									$ 10,000
Disposal group, cash consideration									$ 4,000
GT&S Transaction \| BHE \| Transition Service Agreement
Business Acquisition And Dispositions [Line Items]
Operating revenue		$ 5		$ 16
Disposal group, administrative services description				Dominion Energy will continue to provide specified administrative services to support the operations of the disposed business for up to 24 months after closing, subsequently extended through June 2023 for certain services.
GT&S Transaction \| BHE \| General Partner Interest
Business Acquisition And Dispositions [Line Items]
Noncontrolling partnership interest									100.00%
GT&S Transaction \| BHE \| Limited Partner Interests
Business Acquisition And Dispositions [Line Items]
Noncontrolling partnership interest									25.00%
Q-Pipe Group \| BHE
Business Acquisition And Dispositions [Line Items]
Disposal group, cash consideration								$ 1,300
Q-Pipe Group \| Southwest Gas
Business Acquisition And Dispositions [Line Items]
Disposal group, expected to recognized a gain				$ 685
Disposal group, expected to recognized a gain after tax				500
Goodwill write-off				$ 191
Q-Pipe Group \| Southwest Gas \| Subsequent Event
Business Acquisition And Dispositions [Line Items]
Disposal group, total value of consideration						$ 2,000
Disposal group, cash consideration						$ 1,500
Q-Pipe Transaction \| BHE
Business Acquisition And Dispositions [Line Items]
Disposal group, including discontinued operation, deposits							$ 1,300