Loans and Allowance for Loan Losses - Summary of Financing Receivable, Past Due (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Nonaccrual	$ 6,583	$ 4,790
Total Past Due & Nonaccrual	11,545	12,904
Gross loans	995,298	647,572
Less: Unearned income and deferred costs	(4,271)	(738)
Total	991,027	646,834
30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days past due	4,371	7,120
60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days past due	545	625
Greater than 90 Days Past Due & Accruing [Member]
Financing Receivable, Past Due [Line Items]
Days past due	46	369
Current Loans [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	979,482	633,930
Less: Unearned income and deferred costs	(4,271)	(738)
Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	1,310	441
Total Past Due & Nonaccrual	2,427	2,093
Gross loans	93,286	77,728
Commercial and Industrial [Member] \| 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days past due	1,117	1,652
Commercial and Industrial [Member] \| Current Loans [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	90,859	75,635
Paycheck Protection Program [Member]
Financing Receivable, Past Due [Line Items]
Gross loans	292,068
Paycheck Protection Program [Member] \| Current Loans [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	292,068
Construction, Commercial [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual		929
Total Past Due & Nonaccrual		1,749
Gross loans	54,702	38,039
Construction, Commercial [Member] \| 30-59 Days Past Due [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due		820
Construction, Commercial [Member] \| Current Loans [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	54,702	36,290
Construction, Residential [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due & Nonaccrual	262	241
Gross loans	18,040	26,778
Construction, Residential [Member] \| 30-59 Days Past Due [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	262	241
Construction, Residential [Member] \| Current Loans [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	17,778	26,537
Mortgage, Commercial [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	3,643	1,931
Total Past Due & Nonaccrual	4,849	5,125
Gross loans	273,499	251,824
Mortgage, Commercial [Member] \| 30-59 Days Past Due [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	995	3,194
Mortgage, Commercial [Member] \| 60-89 Days Past Due [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	211
Mortgage, Commercial [Member] \| Current Loans [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	268,650	246,699
Mortgage, Residential [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	916	713
Total Past Due & Nonaccrual	2,024	1,618
Gross loans	213,404	208,494
Mortgage, Residential [Member] \| 30-59 Days Past Due [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	1,062	319
Mortgage, Residential [Member] \| 60-89 Days Past Due [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due		217
Mortgage, Residential [Member] \| Greater than 90 Days Past Due & Accruing [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	46	369
Mortgage, Residential [Member] \| Current Loans [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	211,380	206,876
Mortgage, Farmland [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Gross loans	3,615	5,507
Mortgage, Farmland [Member] \| Current Loans [Member] \| Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	3,615	5,507
Consumer Loans [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	714	776
Total Past Due & Nonaccrual	1,983	2,078
Gross loans	46,684	39,202
Consumer Loans [Member] \| 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days past due	935	894
Consumer Loans [Member] \| 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days past due	334	408
Consumer Loans [Member] \| Current Loans [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	$ 44,701	$ 37,124

Financing receivable total past due and non accrual.

No definition available.

Name:	brbs_FinancingReceivableTotalPastDueAndNonAccrual
Namespace Prefix:	brbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of financing receivable not past due.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953401-111524

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 80
-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922355-210448

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919253-210447

+ Details

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

- Definition

Amount of financing receivable on nonaccrual status.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5111-111524

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919258-210447

+ Details

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

- Definition

Amount of financing receivable past due.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 80
-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922355-210448

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919253-210447

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953401-111524

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentPastDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_FinancingReceivableRecordedInvestmentPastDueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

+ 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 210.9-03.7)
-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 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=121568338&loc=d3e45377-112738

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159169&loc=d3e10152-111534

+ Details

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

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

+ Details

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

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524

+ Details

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

- Details

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables60To89DaysPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=brbs_FinancingReceivableRecordedInvestmentCurrentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=brbs_CommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=brbs_PaycheckProtectionProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=brbs_CommercialConstructionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=brbs_ResidentialConstructionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=brbs_CommercialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=brbs_ResidentialMortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=brbs_FarmlandMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=brbs_ConsumerLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: