Allowance for Credit Losses - Schedule of Collateral Dependent Loans Individually Evaluated (Details) - Collateral Pledged - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
With Allowance
Amortized Cost	$ 10,268	$ 9,875
Related Allowance	8,686	5,854
Amortized Cost, With No Related Allowance	68,617	18,397
Total amortized cost	78,885	28,272
Commercial real estate
With Allowance
Amortized Cost	5,824	7,459
Related Allowance	4,660	4,791
Amortized Cost, With No Related Allowance	46,586	12,439
Total amortized cost	52,410	19,898
Owner-occupied commercial real estate
With Allowance
Amortized Cost	0	0
Related Allowance	0	0
Amortized Cost, With No Related Allowance	5,492	1,833
Total amortized cost	5,492	1,833
Acquisition, construction & development
With Allowance
Amortized Cost	427	535
Related Allowance	194	303
Amortized Cost, With No Related Allowance	12,314	369
Total amortized cost	12,741	904
Commercial & industrial
With Allowance
Amortized Cost	4,017	983
Related Allowance	3,832	734
Amortized Cost, With No Related Allowance	332	348
Total amortized cost	4,349	1,331
Single family residential (1-4 units)
With Allowance
Amortized Cost	0	898
Related Allowance	0	26
Amortized Cost, With No Related Allowance	3,893	3,408
Total amortized cost	3,893	4,306
Consumer non-real estate and other
With Allowance
Amortized Cost	0	0
Related Allowance	0	0
Amortized Cost, With No Related Allowance	0	0
Total amortized cost	$ 0	$ 0

Financing Receivable, Individually Evaluated, With Allowance For Credit Loss

No definition available.

Name:	bhrb_FinancingReceivableIndividuallyEvaluatedWithAllowanceForCreditLossAbstract
Namespace Prefix:	bhrb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of allowance for credit loss on financing receivable evaluated on individual basis. Excludes financing receivable evaluated on collective basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.5.a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480418/310-10-S99-4

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-11B

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 30
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479391/326-20-30-2

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of financing receivable individually evaluated for credit loss. Excludes financing receivable collectively evaluated for credit loss.

+ References

+ Details

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

- Definition

Amount of financing receivable with allowance for credit loss evaluated on individual basis. Excludes financing receivable evaluated on collective basis.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 35
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479366/326-20-35-6

+ Details

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

- Definition

Amount of financing receivable without allowance for credit loss evaluated on individual basis. Excludes financing receivable evaluated on collective basis.

+ References

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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