<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.6.0.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>461</ContextCount>
  <ElementCount>584</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>104</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>10</UnitCount>
  <MyReports>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00090 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00100 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00105 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00200 - Statement - Consolidated Statements Of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/StatementConsolidatedStatementsOfIncome</Role>
      <ShortName>Consolidated Statements Of Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>00300 - Statement - Consolidated Statements Of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/StatementConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statements Of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>00305 - Statement - Consolidated Statements Of Comprehensive Income (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/StatementConsolidatedStatementsOfComprehensiveIncomeParenthetical</Role>
      <ShortName>Consolidated Statements Of Comprehensive Income (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>00400 - Statement - Consolidated Statements Of Changes In Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/StatementConsolidatedStatementsOfChangesInShareholdersEquity</Role>
      <ShortName>Consolidated Statements Of Changes In Shareholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>00405 - Statement - Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/StatementConsolidatedStatementsOfChangesInShareholdersEquityParenthetical</Role>
      <ShortName>Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>00500 - Statement - Consolidated Statements Of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements Of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>10101 - Disclosure - Summary Of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary Of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>10201 - Disclosure - Three-For-Two Common Stock Split</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureThreeForTwoCommonStockSplit</Role>
      <ShortName>Three-For-Two Common Stock Split</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>10301 - Disclosure - Securities Available For Sale</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSale</Role>
      <ShortName>Securities Available For Sale</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>10401 - Disclosure - Loans And Allowance For Loan Losses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLosses</Role>
      <ShortName>Loans And Allowance For Loan Losses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>10501 - Disclosure - Other Real Estate Owned</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwned</Role>
      <ShortName>Other Real Estate Owned</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>10601 - Disclosure - Reclassifications Out Of Accumulated Other Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureReclassificationsOutOfAccumulatedOtherComprehensiveIncome</Role>
      <ShortName>Reclassifications Out Of Accumulated Other Comprehensive Income</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>10701 - Disclosure - Premises And Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosurePremisesAndEquipment</Role>
      <ShortName>Premises And Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>10801 - Disclosure - Goodwill And Other Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureGoodwillAndOtherIntangibleAssets</Role>
      <ShortName>Goodwill And Other Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>10901 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>11001 - Disclosure - Deposits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureDeposits</Role>
      <ShortName>Deposits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>11101 - Disclosure - Short-Term Borrowings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowings</Role>
      <ShortName>Short-Term Borrowings</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>11201 - Disclosure - Long-Term Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLongTermDebt</Role>
      <ShortName>Long-Term Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>11301 - Disclosure - Financial Derivative Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFinancialDerivativeInstruments</Role>
      <ShortName>Financial Derivative Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>11401 - Disclosure - Capital Resources</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCapitalResources</Role>
      <ShortName>Capital Resources</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>11501 - Disclosure - Stock-Based Compensation Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlans</Role>
      <ShortName>Stock-Based Compensation Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>11601 - Disclosure - Retirement Benefit Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlans</Role>
      <ShortName>Retirement Benefit Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>11701 - Disclosure - Commitments And Contingent Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCommitmentsAndContingentLiabilities</Role>
      <ShortName>Commitments And Contingent Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>11801 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>11901 - Disclosure - Fair Value Of Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueOfFinancialInstruments</Role>
      <ShortName>Fair Value Of Financial Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>12001 - Disclosure - Legal Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLegalContingencies</Role>
      <ShortName>Legal Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>12101 - Disclosure - Condensed Financial Information - Parent Company Only</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCondensedFinancialInformationParentCompanyOnly</Role>
      <ShortName>Condensed Financial Information - Parent Company Only</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>12201 - Disclosure - Selected Quarterly Financial Data (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSelectedQuarterlyFinancialDataUnaudited</Role>
      <ShortName>Selected Quarterly Financial Data (Unaudited)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>12301 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>20102 - Disclosure - Summary Of Significant Accounting Policies (Policy)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicy</Role>
      <ShortName>Summary Of Significant Accounting Policies (Policy)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>30303 - Disclosure - Securities Available For Sale (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleTables</Role>
      <ShortName>Securities Available For Sale (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSale</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>30403 - Disclosure - Loans And Allowance For Loan Losses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</Role>
      <ShortName>Loans And Allowance For Loan Losses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLosses</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>30503 - Disclosure - Other Real Estate Owned (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwnedTables</Role>
      <ShortName>Other Real Estate Owned (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwned</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>30603 - Disclosure - Reclassifications Out Of Accumulated Other Comprehensive Income (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureReclassificationsOutOfAccumulatedOtherComprehensiveIncomeTables</Role>
      <ShortName>Reclassifications Out Of Accumulated Other Comprehensive Income (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureReclassificationsOutOfAccumulatedOtherComprehensiveIncome</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>30703 - Disclosure - Premises And Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosurePremisesAndEquipmentTables</Role>
      <ShortName>Premises And Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosurePremisesAndEquipment</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>30803 - Disclosure - Goodwill And Other Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureGoodwillAndOtherIntangibleAssetsTables</Role>
      <ShortName>Goodwill And Other Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureGoodwillAndOtherIntangibleAssets</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>30903 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxes</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>31003 - Disclosure - Deposits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureDepositsTables</Role>
      <ShortName>Deposits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureDeposits</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>31103 - Disclosure - Short-Term Borrowings (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowingsTables</Role>
      <ShortName>Short-Term Borrowings (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowings</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>31203 - Disclosure - Long-Term Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLongTermDebtTables</Role>
      <ShortName>Long-Term Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLongTermDebt</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>31303 - Disclosure - Financial Derivative Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFinancialDerivativeInstrumentsTables</Role>
      <ShortName>Financial Derivative Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFinancialDerivativeInstruments</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>31403 - Disclosure - Capital Resources (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCapitalResourcesTables</Role>
      <ShortName>Capital Resources (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCapitalResources</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>31503 - Disclosure - Stock-Based Compensation Plans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlansTables</Role>
      <ShortName>Stock-Based Compensation Plans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlans</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>31603 - Disclosure - Retirement Benefit Plans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansTables</Role>
      <ShortName>Retirement Benefit Plans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlans</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>31703 - Disclosure - Commitments And Contingent Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCommitmentsAndContingentLiabilitiesTables</Role>
      <ShortName>Commitments And Contingent Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCommitmentsAndContingentLiabilities</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>31803 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueMeasurements</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>31903 - Disclosure - Fair Value Of Financial Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueOfFinancialInstrumentsTables</Role>
      <ShortName>Fair Value Of Financial Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueOfFinancialInstruments</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>32103 - Disclosure - Condensed Financial Information - Parent Company Only (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCondensedFinancialInformationParentCompanyOnlyTables</Role>
      <ShortName>Condensed Financial Information - Parent Company Only (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCondensedFinancialInformationParentCompanyOnly</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>32203 - Disclosure - Selected Quarterly Financial Data (Unaudited) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSelectedQuarterlyFinancialDataUnauditedTables</Role>
      <ShortName>Selected Quarterly Financial Data (Unaudited) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSelectedQuarterlyFinancialDataUnaudited</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>40101 - Disclosure - Summary Of Significant Accounting Policies (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSummaryOfSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>Summary Of Significant Accounting Policies (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicy</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>40201 - Disclosure - Three-For-Two Common Stock Split (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureThreeForTwoCommonStockSplitNarrativeDetails</Role>
      <ShortName>Three-For-Two Common Stock Split (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureThreeForTwoCommonStockSplit</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>40301 - Disclosure - Securities Available For Sale (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleNarrativeDetails</Role>
      <ShortName>Securities Available For Sale (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleTables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>40302 - Disclosure - Securities Available For Sale (Summary Of Securities Available For Sale) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleSummaryOfSecuritiesAvailableForSaleDetails</Role>
      <ShortName>Securities Available For Sale (Summary Of Securities Available For Sale) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>40303 - Disclosure - Securities Available For Sale (Summary Of Maturities Distribution Of The Amortized Cost And Estimated Fair Value Of Securities Available For Sale) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleSummaryOfMaturitiesDistributionOfAmortizedCostAndEstimatedFairValueOfSecuritiesAvailableForSaleDetails</Role>
      <ShortName>Securities Available For Sale (Summary Of Maturities Distribution Of The Amortized Cost And Estimated Fair Value Of Securities Available For Sale) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleTables</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>40304 - Disclosure - Securities Available For Sale (Schedule Of OTTI Related To Historical Estimated Credit Losses On Debt Securities And Changes In Estimated Credit Losses Recognized In Pre-Tax Earnings) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleScheduleOfOttiRelatedToHistoricalEstimatedCreditLossesOnDebtSecuritiesAndChangesInEstimatedCreditLossesRecognizedInPreTaxEarningsDetails</Role>
      <ShortName>Securities Available For Sale (Schedule Of OTTI Related To Historical Estimated Credit Losses On Debt Securities And Changes In Estimated Credit Losses Recognized In Pre-Tax Earnings) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleTables</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>40305 - Disclosure - Securities Available For Sale (Summary Of Fair Value Of Securities With Continuous Unrealized Losses) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleSummaryOfFairValueOfSecuritiesWithContinuousUnrealizedLossesDetails</Role>
      <ShortName>Securities Available For Sale (Summary Of Fair Value Of Securities With Continuous Unrealized Losses) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleTables</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>40306 - Disclosure - Securities Available For Sale (Summary Of Realized Gains And Losses And Other-Than-Temporary Impairment Losses On Securities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleSummaryOfRealizedGainsAndLossesAndOtherThanTemporaryImpairmentLossesOnSecuritiesDetails</Role>
      <ShortName>Securities Available For Sale (Summary Of Realized Gains And Losses And Other-Than-Temporary Impairment Losses On Securities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSecuritiesAvailableForSaleTables</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>40401 - Disclosure - Loans And Allowance For Loan Losses (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesNarrativeDetails</Role>
      <ShortName>Loans And Allowance For Loan Losses (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>40402 - Disclosure - Loans And Allowance For Loan Losses (Summary Of Composition Of Loan Portfolio) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesSummaryOfCompositionOfLoanPortfolioDetails</Role>
      <ShortName>Loans And Allowance For Loan Losses (Summary Of Composition Of Loan Portfolio) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>40404 - Disclosure - Loans And Allowance For Loan Losses (Summary Of Troubled Debt Restructures) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesSummaryOfTroubledDebtRestructuresDetails</Role>
      <ShortName>Loans And Allowance For Loan Losses (Summary Of Troubled Debt Restructures) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>40405 - Disclosure - Loans And Allowance For Loan Losses (Summary Of Post-Modification Balance of Troubled Debt Restructurings) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesSummaryOfPostModificationBalanceOfTroubledDebtRestructuringsDetails</Role>
      <ShortName>Loans And Allowance For Loan Losses (Summary Of Post-Modification Balance of Troubled Debt Restructurings) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>40407 - Disclosure - Loans And Allowance For Loan Losses (Schedule Of Past Due Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesScheduleOfPastDueLoansDetails</Role>
      <ShortName>Loans And Allowance For Loan Losses (Schedule Of Past Due Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>40408 - Disclosure - Loans And Allowance For Loan Losses (Schedule Of Impaired Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesScheduleOfImpairedLoansDetails</Role>
      <ShortName>Loans And Allowance For Loan Losses (Schedule Of Impaired Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>40409 - Disclosure - Loans And Allowance For Loan Losses (Schedule Of Loans With Credit Quality Indicators) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesScheduleOfLoansWithCreditQualityIndicatorsDetails</Role>
      <ShortName>Loans And Allowance For Loan Losses (Schedule Of Loans With Credit Quality Indicators) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>40410 - Disclosure - Loans And Allowance For Loan Losses (Schedule Of Allowance For Loan Losses By Portfolio Segment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesScheduleOfAllowanceForLoanLossesByPortfolioSegmentDetails</Role>
      <ShortName>Loans And Allowance For Loan Losses (Schedule Of Allowance For Loan Losses By Portfolio Segment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>40411 - Disclosure - Loans And Allowance For Loan Losses (Summary Of Loan To Related Parties) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesSummaryOfLoanToRelatedPartiesDetails</Role>
      <ShortName>Loans And Allowance For Loan Losses (Summary Of Loan To Related Parties) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLoansAndAllowanceForLoanLossesTables</ParentRole>
      <Position>69</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>40501 - Disclosure - Other Real Estate Owned (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwnedNarrativeDetails</Role>
      <ShortName>Other Real Estate Owned (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwnedTables</ParentRole>
      <Position>70</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>40502 - Disclosure - Other Real Estate Owned (Schedule Of OREO Activity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwnedScheduleOfOreoActivityDetails</Role>
      <ShortName>Other Real Estate Owned (Schedule Of OREO Activity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwnedTables</ParentRole>
      <Position>71</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>40503 - Disclosure - Other Real Estate Owned (Schedule Of OREO Portfolio By Property Type) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwnedScheduleOfOreoPortfolioByPropertyTypeDetails</Role>
      <ShortName>Other Real Estate Owned (Schedule Of OREO Portfolio By Property Type) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwnedTables</ParentRole>
      <Position>72</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>40504 - Disclosure - Other Real Estate Owned (Net Gains And Losses On OREO Properties) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwnedNetGainsAndLossesOnOreoPropertiesDetails</Role>
      <ShortName>Other Real Estate Owned (Net Gains And Losses On OREO Properties) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureOtherRealEstateOwnedTables</ParentRole>
      <Position>73</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>40601 - Disclosure - Reclassifications Out Of Accumulated Other Comprehensive Income (Summary Of Reclassifications Out Of Accumulated Other Comprehensive Income) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureReclassificationsOutOfAccumulatedOtherComprehensiveIncomeSummaryOfReclassificationsOutOfAccumulatedOtherComprehensiveIncomeDetails</Role>
      <ShortName>Reclassifications Out Of Accumulated Other Comprehensive Income (Summary Of Reclassifications Out Of Accumulated Other Comprehensive Income) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureReclassificationsOutOfAccumulatedOtherComprehensiveIncomeTables</ParentRole>
      <Position>74</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>40701 - Disclosure - Premises And Equipment (Detail Of Premises And Equipment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosurePremisesAndEquipmentDetailOfPremisesAndEquipmentDetails</Role>
      <ShortName>Premises And Equipment (Detail Of Premises And Equipment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosurePremisesAndEquipmentTables</ParentRole>
      <Position>75</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>40801 - Disclosure - Goodwill And Other Intangible Assets (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureGoodwillAndOtherIntangibleAssetsNarrativeDetails</Role>
      <ShortName>Goodwill And Other Intangible Assets (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureGoodwillAndOtherIntangibleAssetsTables</ParentRole>
      <Position>76</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>40802 - Disclosure - Goodwill And Other Intangible Assets (Schedule Of Core Deposits Intangible Assets) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureGoodwillAndOtherIntangibleAssetsScheduleOfCoreDepositsIntangibleAssetsDetails</Role>
      <ShortName>Goodwill And Other Intangible Assets (Schedule Of Core Deposits Intangible Assets) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureGoodwillAndOtherIntangibleAssetsTables</ParentRole>
      <Position>77</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>40901 - Disclosure - Income Taxes (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxesTables</ParentRole>
      <Position>78</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>40902 - Disclosure - Income Taxes (Schedule of Components of Income Tax Expense (Benefit)) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxesScheduleOfComponentsOfIncomeTaxExpenseBenefitDetails</Role>
      <ShortName>Income Taxes (Schedule of Components of Income Tax Expense (Benefit)) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxesTables</ParentRole>
      <Position>79</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>40903 - Disclosure - Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxesScheduleOfEffectiveIncomeTaxRateReconciliationDetails</Role>
      <ShortName>Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxesTables</ParentRole>
      <Position>80</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>40904 - Disclosure - Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxesScheduleOfDeferredTaxAssetsAndLiabilitiesDetails</Role>
      <ShortName>Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureIncomeTaxesTables</ParentRole>
      <Position>81</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>41001 - Disclosure - Deposits (Scheduled Maturities Of Jumbo Certificates Of Deposit) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureDepositsScheduledMaturitiesOfJumboCertificatesOfDepositDetails</Role>
      <ShortName>Deposits (Scheduled Maturities Of Jumbo Certificates Of Deposit) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureDepositsTables</ParentRole>
      <Position>82</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>41002 - Disclosure - Deposits (Scheduled Maturities Of Total Time Deposits) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureDepositsScheduledMaturitiesOfTotalTimeDepositsDetails</Role>
      <ShortName>Deposits (Scheduled Maturities Of Total Time Deposits) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureDepositsTables</ParentRole>
      <Position>83</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>41101 - Disclosure - Short-Term Borrowings (Summary Of Short-Term Borrowings) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowingsSummaryOfShortTermBorrowingsDetails</Role>
      <ShortName>Short-Term Borrowings (Summary Of Short-Term Borrowings) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowingsTables</ParentRole>
      <Position>84</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>41102 - Disclosure - Short-Term Borrowings (Short-Term Federal Home Loan Bank Borrowings) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowingsShortTermFederalHomeLoanBankBorrowingsDetails</Role>
      <ShortName>Short-Term Borrowings (Short-Term Federal Home Loan Bank Borrowings) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowingsTables</ParentRole>
      <Position>85</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>41103 - Disclosure - Short-Term Borrowings (Securities Sold Under Agreements To Repurchase) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowingsSecuritiesSoldUnderAgreementsToRepurchaseDetails</Role>
      <ShortName>Short-Term Borrowings (Securities Sold Under Agreements To Repurchase) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowingsTables</ParentRole>
      <Position>86</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>41104 - Disclosure - Short-Term Borrowings (Securities Collateralizing Repurchase Agreements) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowingsSecuritiesCollateralizingRepurchaseAgreementsDetails</Role>
      <ShortName>Short-Term Borrowings (Securities Collateralizing Repurchase Agreements) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureShortTermBorrowingsTables</ParentRole>
      <Position>87</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>41201 - Disclosure - Long-Term Debt (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLongTermDebtNarrativeDetails</Role>
      <ShortName>Long-Term Debt (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLongTermDebtTables</ParentRole>
      <Position>88</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>41202 - Disclosure - Long-Term Debt (Summary Of Long-Term Debt By Contractual Maturity And With Callable Features) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureLongTermDebtSummaryOfLongTermDebtByContractualMaturityAndWithCallableFeaturesDetails</Role>
      <ShortName>Long-Term Debt (Summary Of Long-Term Debt By Contractual Maturity And With Callable Features) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureLongTermDebtTables</ParentRole>
      <Position>89</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>41301 - Disclosure - Financial Derivative Instruments (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFinancialDerivativeInstrumentsNarrativeDetails</Role>
      <ShortName>Financial Derivative Instruments (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFinancialDerivativeInstrumentsTables</ParentRole>
      <Position>90</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>41302 - Disclosure - Financial Derivative Instruments (Schedule of Notional Amounts of Outstanding Derivative Positions) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFinancialDerivativeInstrumentsScheduleOfNotionalAmountsOfOutstandingDerivativePositionsDetails</Role>
      <ShortName>Financial Derivative Instruments (Schedule of Notional Amounts of Outstanding Derivative Positions) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFinancialDerivativeInstrumentsTables</ParentRole>
      <Position>91</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>41303 - Disclosure - Financial Derivative Instruments (Schedule of Interest Rate Derivatives) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFinancialDerivativeInstrumentsScheduleOfInterestRateDerivativesDetails</Role>
      <ShortName>Financial Derivative Instruments (Schedule of Interest Rate Derivatives) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFinancialDerivativeInstrumentsTables</ParentRole>
      <Position>92</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>41401 - Disclosure - Capital Resources (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCapitalResourcesNarrativeDetails</Role>
      <ShortName>Capital Resources (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCapitalResourcesTables</ParentRole>
      <Position>93</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>41402 - Disclosure - Capital Resources (The Company's And The Bank's Regulatory Capital) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCapitalResourcesCompanySAndBankSRegulatoryCapitalDetails</Role>
      <ShortName>Capital Resources (The Company's And The Bank's Regulatory Capital) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCapitalResourcesTables</ParentRole>
      <Position>94</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>41501 - Disclosure - Stock-Based Compensation Plans (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlansNarrativeDetails</Role>
      <ShortName>Stock-Based Compensation Plans (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlansTables</ParentRole>
      <Position>95</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>41502 - Disclosure - Stock-Based Compensation Plans (Allocation Of Recognized Period Costs) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlansAllocationOfRecognizedPeriodCostsDetails</Role>
      <ShortName>Stock-Based Compensation Plans (Allocation Of Recognized Period Costs) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlansTables</ParentRole>
      <Position>96</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>41503 - Disclosure - Stock-Based Compensation Plans (Schedule Of Fair Value Assumptions) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlansScheduleOfFairValueAssumptionsDetails</Role>
      <ShortName>Stock-Based Compensation Plans (Schedule Of Fair Value Assumptions) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlansTables</ParentRole>
      <Position>97</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>41504 - Disclosure - Stock-Based Compensation (Summary Of Stock Option And Restricted Stock Awards Activity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationSummaryOfStockOptionAndRestrictedStockAwardsActivityDetails</Role>
      <ShortName>Stock-Based Compensation (Summary Of Stock Option And Restricted Stock Awards Activity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlansTables</ParentRole>
      <Position>98</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>41505 - Disclosure - Stock-Based Compensation (Summary Of Stock Units Activity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationSummaryOfStockUnitsActivityDetails</Role>
      <ShortName>Stock-Based Compensation (Summary Of Stock Units Activity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureStockBasedCompensationPlansTables</ParentRole>
      <Position>99</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>41601 - Disclosure - Retirement Benefit Plans (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansNarrativeDetails</Role>
      <ShortName>Retirement Benefit Plans (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansTables</ParentRole>
      <Position>100</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>41602 - Disclosure - Retirement Benefit Plans (Changes In Benefit Obligations, Changes In Plan Assets And The Funded Status Of The Plans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansChangesInBenefitObligationsChangesInPlanAssetsAndFundedStatusOfPlansDetails</Role>
      <ShortName>Retirement Benefit Plans (Changes In Benefit Obligations, Changes In Plan Assets And The Funded Status Of The Plans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansTables</ParentRole>
      <Position>101</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>41603 - Disclosure - Retirement Benefit Plans (Summary Of Assumptions Used In Determining The Benefit Obligations And Net Periodic Benefit Costs) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansSummaryOfAssumptionsUsedInDeterminingBenefitObligationsAndNetPeriodicBenefitCostsDetails</Role>
      <ShortName>Retirement Benefit Plans (Summary Of Assumptions Used In Determining The Benefit Obligations And Net Periodic Benefit Costs) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansTables</ParentRole>
      <Position>102</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>41604 - Disclosure - Retirement Benefit Plans (Schedule Of Components Of Net Periodic Benefit Cost) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansScheduleOfComponentsOfNetPeriodicBenefitCostDetails</Role>
      <ShortName>Retirement Benefit Plans (Schedule Of Components Of Net Periodic Benefit Cost) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansTables</ParentRole>
      <Position>103</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>41605 - Disclosure - Retirement Benefit Plans (Schedule Of Expected Contributions To Fund Benefit Payments Under Supplemental Executive Retirement Plans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansScheduleOfExpectedContributionsToFundBenefitPaymentsUnderSupplementalExecutiveRetirementPlansDetails</Role>
      <ShortName>Retirement Benefit Plans (Schedule Of Expected Contributions To Fund Benefit Payments Under Supplemental Executive Retirement Plans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureRetirementBenefitPlansTables</ParentRole>
      <Position>104</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>41701 - Disclosure - Commitments And Contingent Liabilities (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCommitmentsAndContingentLiabilitiesNarrativeDetails</Role>
      <ShortName>Commitments And Contingent Liabilities (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCommitmentsAndContingentLiabilitiesTables</ParentRole>
      <Position>105</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>41702 - Disclosure - Commitments And Contingent Liabilities (Schedule Of Contractual Amounts Of Commitments And Contingent Liabilities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCommitmentsAndContingentLiabilitiesScheduleOfContractualAmountsOfCommitmentsAndContingentLiabilitiesDetails</Role>
      <ShortName>Commitments And Contingent Liabilities (Schedule Of Contractual Amounts Of Commitments And Contingent Liabilities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCommitmentsAndContingentLiabilitiesTables</ParentRole>
      <Position>106</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>41703 - Disclosure - Commitments And Contingent Liabilities (Schedule of Future Minimum Rental Payments for Operating Leases) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCommitmentsAndContingentLiabilitiesScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesDetails</Role>
      <ShortName>Commitments And Contingent Liabilities (Schedule of Future Minimum Rental Payments for Operating Leases) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCommitmentsAndContingentLiabilitiesTables</ParentRole>
      <Position>107</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>41801 - Disclosure - Fair Value Measurements (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueMeasurementsNarrativeDetails</Role>
      <ShortName>Fair Value Measurements (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueMeasurementsTables</ParentRole>
      <Position>108</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>41802 - Disclosure - Fair Value Measurements (Financial Assets And Financial Liabilities Measured At Fair Value On A Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueMeasurementsFinancialAssetsAndFinancialLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails</Role>
      <ShortName>Fair Value Measurements (Financial Assets And Financial Liabilities Measured At Fair Value On A Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueMeasurementsTables</ParentRole>
      <Position>109</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>41803 - Disclosure - Fair Value Measurements (Financial Assets And Financial Liabilities Measured At Fair Value On A Non-Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueMeasurementsFinancialAssetsAndFinancialLiabilitiesMeasuredAtFairValueOnNonRecurringBasisDetails</Role>
      <ShortName>Fair Value Measurements (Financial Assets And Financial Liabilities Measured At Fair Value On A Non-Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueMeasurementsTables</ParentRole>
      <Position>110</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>41901 - Disclosure - Fair Value Of Financial Instruments (Summary Of The Carrying Values And Estimated Fair Values Of Financial Instruments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueOfFinancialInstrumentsSummaryOfCarryingValuesAndEstimatedFairValuesOfFinancialInstrumentsDetails</Role>
      <ShortName>Fair Value Of Financial Instruments (Summary Of The Carrying Values And Estimated Fair Values Of Financial Instruments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureFairValueOfFinancialInstrumentsTables</ParentRole>
      <Position>111</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>42101 - Disclosure - Condensed Financial Information - Parent Company Only (Balance Sheets) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCondensedFinancialInformationParentCompanyOnlyBalanceSheetsDetails</Role>
      <ShortName>Condensed Financial Information - Parent Company Only (Balance Sheets) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCondensedFinancialInformationParentCompanyOnlyTables</ParentRole>
      <Position>112</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>42102 - Disclosure - Condensed Financial Information - Parent Company Only (Statements Of Income) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCondensedFinancialInformationParentCompanyOnlyStatementsOfIncomeDetails</Role>
      <ShortName>Condensed Financial Information - Parent Company Only (Statements Of Income) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCondensedFinancialInformationParentCompanyOnlyTables</ParentRole>
      <Position>113</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>42103 - Disclosure - Condensed Financial Information - Parent Company Only (Statements Of Cash Flow) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureCondensedFinancialInformationParentCompanyOnlyStatementsOfCashFlowDetails</Role>
      <ShortName>Condensed Financial Information - Parent Company Only (Statements Of Cash Flow) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureCondensedFinancialInformationParentCompanyOnlyTables</ParentRole>
      <Position>114</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>42201 - Disclosure - Selected Quarterly Financial Data (Unaudited) (Schedule of Selected Quarterly Financial Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSelectedQuarterlyFinancialDataUnauditedScheduleOfSelectedQuarterlyFinancialInformationDetails</Role>
      <ShortName>Selected Quarterly Financial Data (Unaudited) (Schedule of Selected Quarterly Financial Information) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSelectedQuarterlyFinancialDataUnauditedTables</ParentRole>
      <Position>115</Position>
    </Report>
    <Report instance="bhb-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>42301 - Disclosure - Subsequent Events (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bhbt.com/2011-03-31/role/DisclosureSubsequentEventsNarrativeDetails</Role>
      <ShortName>Subsequent Events (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bhbt.com/2011-03-31/role/DisclosureSubsequentEvents</ParentRole>
      <Position>116</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>bhb-20161231.xml</File>
    <File>bhb-20161231.xsd</File>
    <File>bhb-20161231_cal.xml</File>
    <File>bhb-20161231_def.xml</File>
    <File>bhb-20161231_lab.xml</File>
    <File>bhb-20161231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies/>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
