Federal home loan bank advances maximum borrowing capacity percentage on assets.

No definition available.

Name:	brbs_FederalHomeLoanBankAdvancesMaximumBorrowingCapacityPercentageOnAssets
Namespace Prefix:	brbs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Fixed annual cost basis points.

+ References

No definition available.

+ Details

Name:	brbs_FixedAnnualCostBasisPoints
Namespace Prefix:	brbs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum overnight line of credit facilities available.

+ References

No definition available.

+ Details

Name:	brbs_MaximumOvernightLineOfCreditFacilitiesAvailable
Namespace Prefix:	brbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of advances.

+ References

No definition available.

+ Details

Name:	brbs_NumberOfAdvances
Namespace Prefix:	brbs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Overnight line of credit facilities outstanding.

+ References

No definition available.

+ Details

Name:	brbs_OvernightLineOfCreditFacilitiesOutstanding
Namespace Prefix:	brbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage of advances on paycheck protection program loan value and term.

+ References

No definition available.

+ Details

Name:	brbs_PercentageOfAdvancesOnPaycheckProtectionProgramLoanValueAndTerm
Namespace Prefix:	brbs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage reduction in tier 2 capital treatment in each year.

+ References

No definition available.

+ Details

Name:	brbs_PercentageReductionInTierTwoCapitalTreatmentInEachYear
Namespace Prefix:	brbs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Principal amount with interest accrued of redemption.

+ References

No definition available.

+ Details

Name:	brbs_PrincipalAmountWithInterestAccruedOfRedemption
Namespace Prefix:	brbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

+ Details

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of a feature that permits the issuer of the debt to repay or convert it before the stated maturity date (early retirement date). The description may include such items as the call price, the period that the issuer can call the debt, including the earliest call date, and other significant terms of the call feature, which may include the debt holders' ability to convert the debt to equity if the call option is exercised and contingent events that trigger the issuer's ability to call the debt.

+ 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)(5))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Date the debt agreement requires the first payment to be made, in CCYY-MM-DD format.

+ 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)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentDateOfFirstRequiredPayment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- 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

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6036836-161870

Reference 2: 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 3: 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_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

+ References

+ Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

+ Details

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

- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

+ Details

Name:	us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(3)(a))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

Reference 3: 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 (b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 325
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=75031641&loc=d3e63345-112809

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Date the payments are due on subordinated debt, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_SubordinatedBorrowingDueDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Stated interest rate of the subordinated debt.

+ References

No definition available.

+ Details

Name:	us-gaap_SubordinatedBorrowingInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

+ Details

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

- Details

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

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=brbs_SecuredOvernightFinancingRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_UnusedLinesOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=brbs_FederalReservePaycheckProtectionProgramLiquidityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=us-gaap_FederalHomeLoanBankBorrowingsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=brbs_RestrictedInvestmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=brbs_OneToFourFamilyResidentialLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=brbs_MultiFamilyResidentialLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=brbs_CommercialRealEstateLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=brbs_OneToFourFamilyResidentialLoansHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=brbs_SecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=brbs_VirginiaPublicDepositsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Borrowings - Additional Information (Detail)	1 Months Ended		3 Months Ended	12 Months Ended
Borrowings - Additional Information (Detail)	May 28, 2020 USD ($)	Nov. 20, 2015 USD ($)	Jun. 30, 2020 USD ($) Advance	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Federal home loan bank advance				$ 115,000,000	$ 124,800,000
Federal home loan bank stock				5,800,000	6,000,000
Subordinated debt [Member]
Debt Instrument [Line Items]
Subordinated debt instrument face value	$ 15,000,000	$ 10,000,000
Subordinated debt instrument maturity date	Jun. 01, 2030	Dec. 01, 2025
Subordinated debt interest rate terms	The 2020 Note bears interest, payable on the 1st of June and December of each year, commencing December 1, 2020, at a fixed rate of 6.00% per year for the first five years, and thereafter will bear a floating interest rate of SOFR (as defined in the note) plus 587 basis points.	The 2015 Notes bear interest, payable on the 1st of June and December of each year, commencing June 1, 2016, at a fixed rate of 6.75% per year for the first five years, and thereafter will bear a floating interest rate of LIBOR plus 512.8 basis points.
Subordinated debt instrument fixed rate of interest	6.00%	6.75%
Subordinated debt instrument call feature	The Company has the right to redeem the 2020 Note, in whole or in part, without premium or penalty, at any interest payment date on or after June 1, 2025 and prior to the maturity date, but in all cases in a principal amount with integral multiples of $1,000, plus interest accrued and unpaid through the date of redemption	The Company has the right to redeem the 2015 Notes, in whole or in part, without premium or penalty, at any interest payment date on or after December 1, 2020 and prior to the maturity date, but in all cases in a principal amount with integral multiples of $1,000, plus interest accrued and unpaid through the date of redemption
Subordinated debt instrument date of first required payment	Dec. 01, 2020	Jun. 01, 2016
Subordinate debt principal amount with interest accrued	$ 1,000	$ 1,000
Subordinated debt [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Subordinated debt instrument variable interest rate spread		512.80%
Subordinated debt [Member] \| SOFR [Member]
Debt Instrument [Line Items]
Subordinated debt instrument variable interest rate spread	587.00%
Subordinated debt [Member] \| 2015 Notes [Member]
Debt Instrument [Line Items]
Unamortized debt issuance cost				$ 9,800,000	$ 9,800,000
Effective interest rate				6.86%	6.89%
Percentage reduction in tier 2 capital treatment in each year				20.00%
Subordinated debt [Member] \| 2020 Notes [Member]
Debt Instrument [Line Items]
Unamortized debt issuance cost				$ 14,700,000
Effective interest rate				6.17%
Percentage reduction in tier 2 capital treatment in each year				20.00%
Unsecured Lines of Credit [Member]
Debt Instrument [Line Items]
Maximum overnight line of credit facilities available				$ 38,000,000	$ 24,000,000
Overnight line of credit facilities outstanding				$ 0	0
Federal Reserve Paycheck Protection Program Liquidity [Member]
Debt Instrument [Line Items]
Percentage of advances on PPP loan value and term			100.00%
Fixed annual cost basis points			35.00%
Number of advances \| Advance			23
Total advances			$ 281,600
Minimum [Member] \| Federal Reserve Paycheck Protection Program Liquidity [Member]
Debt Instrument [Line Items]
Borrowing maturity			1 year 2 months 12 days
Maximum [Member] \| Federal Reserve Paycheck Protection Program Liquidity [Member]
Debt Instrument [Line Items]
Borrowing maturity			4 years 6 months
FHLB [Member]
Debt Instrument [Line Items]
Federal home loan bank advances, maximum borrowing capacity percentage on assets				30.00%
Federal home loan bank advance				$ 115,000,000	$ 124,800,000
FHLB [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Federal home loan bank, advances, interest Rate				0.22%
FHLB [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Federal home loan bank, advances, interest Rate				0.25%
FHLB [Member] \| Restricted Investments [Member]
Debt Instrument [Line Items]
Federal home loan bank stock				$ 5,800,000
FHLB [Member] \| Line of Credit [Member]
Debt Instrument [Line Items]
Federal home loan bank, advances, general debt obligations, amount available				177,100,000
FHLB [Member] \| Line of Credit [Member] \| 1-4 Family Residential Loans [Member]
Debt Instrument [Line Items]
Assets pledged with federal home loan bank against credit facilities				49,900,000
FHLB [Member] \| Line of Credit [Member] \| Multi-Family Residential Loans [Member]
Debt Instrument [Line Items]
Assets pledged with federal home loan bank against credit facilities				10,000,000
FHLB [Member] \| Line of Credit [Member] \| Commercial Real Estate Loans [Member]
Debt Instrument [Line Items]
Assets pledged with federal home loan bank against credit facilities				65,700,000
FHLB [Member] \| Line of Credit [Member] \| 1-4 Family Residential Loans Held for Sale [Member]
Debt Instrument [Line Items]
Assets pledged with federal home loan bank against credit facilities				23,200,000
FHLB [Member] \| Line of Credit [Member] \| Securities [Member]
Debt Instrument [Line Items]
Assets pledged with federal home loan bank against credit facilities				28,300,000
FHLB [Member] \| Letter of Credit [Member] \| Public Deposits with Treasury Board of Virginia [Member]
Debt Instrument [Line Items]
Assets pledged with federal home loan bank against credit facilities				$ 20,000,000