Credit Risk (Narrative) (Detail)	9 Months Ended
Sep. 30, 2022 USD ($) counterparty	Dec. 31, 2021 USD ($)
Concentration Risk and Guarantor Obligations [Line Items]
Credit exposure	$ 133,000,000
Additional collateral to be posted if the credit related contingent features were triggered	189,000,000	$ 31,000,000
Collateral derivatives with credit-related contingent provision in a liability position	124,000,000	66,000,000
Letter of credit as collateral posted for derivatives in liability position	53,000,000
Aggregate fair value of all derivative instruments with credit contingent provisions that are in a liability position	313,000,000	97,000,000
Virginia Electric and Power Company
Concentration Risk and Guarantor Obligations [Line Items]
Credit exposure	17,000,000
Additional collateral to be posted if the credit related contingent features were triggered	58,000,000	22,000,000
Collateral derivatives with credit-related contingent provision in a liability position	121,000,000	54,000,000
Letter of credit as collateral posted for derivatives in liability position	53,000,000
Aggregate fair value of all derivative instruments with credit contingent provisions that are in a liability position	$ 179,000,000	$ 76,000,000
Credit Concentration Risk
Concentration Risk and Guarantor Obligations [Line Items]
Number of counterparties \| counterparty	0
Amount of exposure for single counterparty	$ 45,000,000
Credit Concentration Risk \| Wholesale Customers \| Sales Revenue, Net \| Virginia Electric and Power Company
Concentration Risk and Guarantor Obligations [Line Items]
Number of counterparties \| counterparty	0
Amount of exposure for single counterparty	$ 4,000,000
Credit Concentration Risk \| Investment Grade \| Investment Grade Counterparty
Concentration Risk and Guarantor Obligations [Line Items]
Concentration risk, percentage (percentage)	88.00%
Credit Concentration Risk \| Investment Grade \| Investment Grade Counterparty \| Virginia Electric and Power Company
Concentration Risk and Guarantor Obligations [Line Items]
Concentration risk, percentage (percentage)	78.00%

Concentration Risk and Guarantor Obligations [Line Items]

No definition available.

Name:	d_ConcentrationRiskAndGuarantorObligationsLineItems
Namespace Prefix:	d_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Concentration risk, credit risk, financial instrument, maximum exposure for single counterparty.

+ References

No definition available.

+ Details

Name:	d_ConcentrationRiskCreditRiskFinancialInstrumentMaximumExposureForSingleCounterparty
Namespace Prefix:	d_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Concentration risk credit risk number of counterparties.

+ References

No definition available.

+ Details

Name:	d_ConcentrationRiskCreditRiskNumberOfCounterparties
Namespace Prefix:	d_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Letter of credit as collateral posted for derivatives in liability position fair value.

+ References

No definition available.

+ Details

Name:	d_LetterOfCreditAsCollateralPostedForDerivativesInLiabilityPositionFairValue
Namespace Prefix:	d_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624258-113959

+ Details

Name:	us-gaap_AdditionalCollateralAggregateFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624258-113959

+ Details

Name:	us-gaap_CollateralAlreadyPostedAggregateFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13537-108611

+ Details

Name:	us-gaap_ConcentrationRiskCreditRiskFinancialInstrumentMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI https://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13531-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13537-108611

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI https://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624258-113959

+ Details

Name:	us-gaap_DerivativeNetLiabilityPositionAggregateFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=d_VirginiaElectricAndPowerCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CreditConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=d_WholesaleCustomersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=d_InternalAndExternalCreditRatingInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=d_InvestmentGradeCounterpartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: