Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

+ Details

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

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

+ Details

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

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

+ Details

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

- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

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

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=bhb_LoansFromBusinessActivitiesMember
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=bhb_CommercialandIndustrialLoansPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=bhb_LoansAcquiredFromBusinessCombinationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

LOAN LOSS ALLOWANCE - Allowance Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Activity in the allowance for loan losses
Balance at beginning of period			$ 10,419
Provision/(releases) for loan losses	$ 736	$ 150	1,531	$ 615
Balance at end of period	11,442		11,442
Allowance For Loan Losses
Total	11,442		10,419		$ 11,442
Business Activities Loans
Activity in the allowance for loan losses
Balance at beginning of period			10,419	9,439
Charged-off loans			(579)	(263)
Recoveries on charged-off loans			71	100
Provision/(releases) for loan losses			1,422	615
Balance at end of period	11,333	9,891	11,333	9,891
Allowance For Loan Losses
Individually evaluated for impairment					394	$ 370
Collectively evaluated					10,939	9,521
Total	11,333	9,891	10,419	9,439	11,333	9,891
Business Activities Loans \| Commercial real estate
Activity in the allowance for loan losses
Balance at beginning of period			5,145	4,430
Charged-off loans			(147)	(34)
Recoveries on charged-off loans			3	13
Provision/(releases) for loan losses			502	451
Balance at end of period	5,503	4,860	5,503	4,860
Allowance For Loan Losses
Individually evaluated for impairment					380	103
Collectively evaluated					5,123	4,757
Total	5,503	4,860	5,145	4,430	5,503	4,860
Business Activities Loans \| Commercial and industrial
Activity in the allowance for loan losses
Balance at beginning of period			1,952	1,590
Charged-off loans			(189)	(90)
Recoveries on charged-off loans			2	44
Provision/(releases) for loan losses			345	157
Balance at end of period	2,110	1,701	2,110	1,701
Allowance For Loan Losses
Individually evaluated for impairment					4	175
Collectively evaluated					2,106	1,526
Total	2,110	1,701	1,952	1,590	2,110	1,701
Business Activities Loans \| Residential real estate
Activity in the allowance for loan losses
Balance at beginning of period			2,721	2,747
Charged-off loans			(226)	(122)
Recoveries on charged-off loans			64	28
Provision/(releases) for loan losses			560	30
Balance at end of period	3,119	2,683	3,119	2,683
Allowance For Loan Losses
Individually evaluated for impairment					10	54
Collectively evaluated					3,109	2,629
Total	3,119	2,683	2,721	2,747	3,119	2,683
Business Activities Loans \| Consumer
Activity in the allowance for loan losses
Balance at beginning of period			601	672
Charged-off loans			(17)	(17)
Recoveries on charged-off loans			2	15
Provision/(releases) for loan losses			15	(23)
Balance at end of period	601	647	601	647
Allowance For Loan Losses
Individually evaluated for impairment					0	38
Collectively evaluated					601	609
Total	601	$ 647	601	$ 672	601	$ 647
Acquired Loans
Activity in the allowance for loan losses
Balance at beginning of period			0
Charged-off loans			0
Recoveries on charged-off loans			0
Provision/(releases) for loan losses			109
Balance at end of period	109		109
Allowance For Loan Losses
Individually evaluated for impairment					109
Collectively evaluated					0
Total	109		0		109
Acquired Loans \| Commercial real estate
Activity in the allowance for loan losses
Balance at beginning of period			0
Charged-off loans			0
Recoveries on charged-off loans			0
Provision/(releases) for loan losses			51
Balance at end of period	51		51
Allowance For Loan Losses
Individually evaluated for impairment					51
Collectively evaluated					0
Total	51		0		51
Acquired Loans \| Commercial and industrial
Activity in the allowance for loan losses
Balance at beginning of period			0
Charged-off loans			0
Recoveries on charged-off loans			0
Provision/(releases) for loan losses			24
Balance at end of period	24		24
Allowance For Loan Losses
Individually evaluated for impairment					24
Collectively evaluated					0
Total	24		0		24
Acquired Loans \| Residential real estate
Activity in the allowance for loan losses
Balance at beginning of period			0
Charged-off loans			0
Recoveries on charged-off loans			0
Provision/(releases) for loan losses			34
Balance at end of period	34		34
Allowance For Loan Losses
Individually evaluated for impairment					34
Collectively evaluated					0
Total	34		0		34
Acquired Loans \| Consumer
Activity in the allowance for loan losses
Balance at beginning of period			0
Charged-off loans			0
Recoveries on charged-off loans			0
Provision/(releases) for loan losses			0
Balance at end of period	0		0
Allowance For Loan Losses
Individually evaluated for impairment					0
Collectively evaluated					0
Total	$ 0		$ 0		$ 0