Capacity of facility of company owned solar distribution generation facilities.

No definition available.

Name:	d_CapacityOfFacilityOfCompanyOwnedSolarDistributionGenerationFacilities
Namespace Prefix:	d_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	duration

- Definition

Gain (loss) on disposition of property plant and equipment, net of tax.

+ References

No definition available.

+ Details

Name:	d_GainLossOnDispositionOfPropertyPlantAndEquipmentNetOfTax
Namespace Prefix:	d_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Gas and oil area, developed, net, remaining interest conveyed, percentage.

+ References

No definition available.

+ Details

Name:	d_GasAndOilAreaDevelopedNetRemainingInterestConveyedPercentage
Namespace Prefix:	d_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of solar development projects acquired.

+ References

No definition available.

+ Details

Name:	d_NumberOfSolarDevelopmentProjectsAcquired
Namespace Prefix:	d_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Oil and gas property, number of natural gas storage fields.

+ References

No definition available.

+ Details

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

- Definition

Area assigned to productive oil and gas wells representing summation of fractional ownership working interest to whole.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1208
-Paragraph (a)

+ Details

Name:	srt_GasAndOilAreaDevelopedNet
Namespace Prefix:	srt_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainLossOnSaleOfPropertyPlantEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow from the amount invested for projects in hopes of getting a future return or interest from it.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireProjects
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=d_SolarDevelopmentProjectInVirginiaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=d_TwoSolarDevelopmentProjectsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=d_FirstSolarDevelopmentProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=d_SecondSolarDevelopmentProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_StatementGeographicalAxis=d_MarcellusShaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_OilAndGasPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=d_UticaAndPointPleasantShaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=d_OtherOperationsAndMaintenanceExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Property Plant and Equipment (Narrative) (Detail) $ in Millions	1 Months Ended						3 Months Ended		12 Months Ended
	Apr. 30, 2019 USD ($) MW	Jan. 31, 2019 MW	Aug. 31, 2018 project	Mar. 31, 2018 USD ($) a field	Feb. 28, 2018 USD ($)	Jan. 31, 2018 a	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($) a field	Dec. 31, 2020 USD ($) MW	Dec. 31, 2019 USD ($)	Nov. 30, 2014 a field
Property Plant And Equipment [Line Items]
Cost of project							$ 29	$ 7
Virginia Electric and Power Company
Property Plant And Equipment [Line Items]
Cost of project							$ 27
MW Capacity \| MW		1,292
Virginia Electric and Power Company \| Solar Development Project in Virginia
Property Plant And Equipment [Line Items]
Cost of project	$ 37
MW Capacity \| MW	20
Virginia Electric and Power Company \| Two Solar Development Projects
Property Plant And Equipment [Line Items]
Number of Projects \| project			2
Virginia Electric and Power Company \| Two Solar Development Projects \| Scenario Forecast
Property Plant And Equipment [Line Items]
MW Capacity \| MW									155
Virginia Electric and Power Company \| First Solar Development Project \| Subsequent Event
Property Plant And Equipment [Line Items]
Cost of project										$ 120
Virginia Electric and Power Company \| Second Solar Development Project \| Scenario Forecast
Property Plant And Equipment [Line Items]
Cost of project									$ 130
Dominion Energy Gas Holdings, LLC \| Marcellus Shale \| Oil and Gas Properties
Property Plant And Equipment [Line Items]
Development rights (number of acres) \| a						18,000					24,000
Number of natural gas storage fields \| field											1
Gas and oil area developed net remaining interest conveyed percentage						50.00%
Amount of consideration					$ 28
Dominion Energy Gas Holdings, LLC \| Utica and Point Pleasant Shale \| Oil and Gas Properties
Property Plant And Equipment [Line Items]
Development rights (number of acres) \| a				11,000				11,000
Number of natural gas storage fields \| field				1				1
Amount of consideration				$ 16				$ 16
Proceeds from assignment of Shale Development Rights				16
Dominion Energy Gas Holdings, LLC \| Other operations and maintenance \| Marcellus Shale \| Oil and Gas Properties
Property Plant And Equipment [Line Items]
Gain on sale					28
After tax gain on sale					$ 20
Dominion Energy Gas Holdings, LLC \| Other operations and maintenance \| Utica and Point Pleasant Shale \| Oil and Gas Properties
Property Plant And Equipment [Line Items]
Gain on sale				16
After tax gain on sale				$ 12