Debt instrument maturity month and year.

No definition available.

Name:	d_DebtInstrumentMaturityMonthAndYear
Namespace Prefix:	d_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

Estimated Mandatory Prepayments Due Within One Year

+ References

No definition available.

+ Details

Name:	d_EstimatedMandatoryPrepaymentsDueWithinOneYear
Namespace Prefix:	d_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

- Definition

Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

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

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis=d_June2006HybridsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis=d_September2006HybridsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis=d_JuneTwoZeroZeroSixAndSeptemberTwoZeroZeroSixHybridsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=d_TwoPointFiveSevenNinePercentJuniorSubordinatedNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=d_FloatingRateSeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=d_FourPointSevenFivePercentMediumTermNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=d_FourPointOneTwoFivePercentMediumTermNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LoansPayableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Long-Term Debt (Based on Stated Maturity Dates Rather than Early Redemption Dates that Could be Elected by Instrument Holders) (Parenthetical) (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2020	Apr. 30, 2020	Mar. 31, 2020	Feb. 29, 2020	Dec. 31, 2019
June2006 Hybrids
Debt Instrument [Line Items]
Debt, amount redeemed					$ 111
September 2006 hybrids
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 13
Debt, amount redeemed					286
June 2006 and September 2006 Hybrids
Debt Instrument [Line Items]
Debt instrument, maturity date, description		both of which would have otherwise matured in 2066
2.579% Junior Subordinated Notes
Debt Instrument [Line Items]
Interest Rate		2.579%
Debt, amount redeemed			$ 7
Debt maturity month and year		2020-07
Debt instrument prepaid, amount	$ 993
DS C A N A
Debt Instrument [Line Items]
Debt instrument, maturity date, description		The notes would have otherwise matured in May 2021 and February 2022, respectively.
DS C A N A \| Floating rate senior notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 66
Debt instrument, maturity date, description		The notes would have otherwise matured in June 2034
DS C A N A \| Four Point Seven Five Percent Medium Term Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount					$ 183
Interest Rate					4.75%
DS C A N A \| Four Point One Two Five Percent Medium Term Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount					$ 155
Interest Rate					4.125%
Term loans
Debt Instrument [Line Items]
Estimated mandatory prepayments due within one year		$ 22