<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>397</ContextCount>
  <ElementCount>617</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>98</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>12</UnitCount>
  <MyReports>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>995200090 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>995200100 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>995200105 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>995200200 - Statement - CONSOLIDATED STATEMENTS OF INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/StatementConsolidatedStatementsOfIncome</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>995200300 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/StatementConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>995200400 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/StatementConsolidatedStatementsOfChangesInShareholdersEquity</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>995200405 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/StatementConsolidatedStatementsOfChangesInShareholdersEquityParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>995200500 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>995210101 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995210201 - Disclosure - Accumulated Other Comprehensive Income (''AOCI")</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureAccumulatedOtherComprehensiveIncomeAoci</Role>
      <ShortName>Accumulated Other Comprehensive Income (''AOCI")</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995210301 - Disclosure - Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecurities</Role>
      <ShortName>Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995210401 - Disclosure - Loans and Allowance for Credit Losses on Loans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoans</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995210501 - Disclosure - Loan Servicing</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoanServicing</Role>
      <ShortName>Loan Servicing</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995210601 - Disclosure - Premises and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosurePremisesAndEquipment</Role>
      <ShortName>Premises and Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995210701 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLeases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995210801 - Disclosure - Goodwill and Other Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureGoodwillAndOtherIntangibleAssets</Role>
      <ShortName>Goodwill and Other Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995210901 - Disclosure - Deposits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureDeposits</Role>
      <ShortName>Deposits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995211001 - Disclosure - Borrowing Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBorrowingArrangements</Role>
      <ShortName>Borrowing Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995211101 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995211201 - Disclosure - Equity Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureEquityPlan</Role>
      <ShortName>Equity Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995211301 - Disclosure - Benefit Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlans</Role>
      <ShortName>Benefit Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995211401 - Disclosure - Fair Value</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureFairValue</Role>
      <ShortName>Fair Value</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995211501 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995211601 - Disclosure - Shareholders' Equity and Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureShareholdersEquityAndEarningsPerShare</Role>
      <ShortName>Shareholders' Equity and Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995211701 - Disclosure - Capital Requirements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureCapitalRequirements</Role>
      <ShortName>Capital Requirements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995211801 - Disclosure - Revenue Recognition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureRevenueRecognition</Role>
      <ShortName>Revenue Recognition</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995211901 - Disclosure - Noninterest Expense</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureNoninterestExpense</Role>
      <ShortName>Noninterest Expense</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995212001 - Disclosure - Business Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBusinessSegmentInformation</Role>
      <ShortName>Business Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995212101 - Disclosure - Parent Company only Condensed Financial Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureParentCompanyOnlyCondensedFinancialInformation</Role>
      <ShortName>Parent Company only Condensed Financial Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995212201 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995410 - Disclosure - Pay vs Performance Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/PvpDisclosure</Role>
      <ShortName>Pay vs Performance Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995445 - Disclosure - Insider Trading Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements</Role>
      <ShortName>Insider Trading Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995447 - Disclosure - Insider Trading Policies and Procedures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc</Role>
      <ShortName>Insider Trading Policies and Procedures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure</Role>
      <ShortName>Cybersecurity Risk Management and Strategy Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>99920102 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>99930203 - Disclosure - Accumulated Other Comprehensive Income (''AOCI'') (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureAccumulatedOtherComprehensiveIncomeAociTables</Role>
      <ShortName>Accumulated Other Comprehensive Income (''AOCI'') (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureAccumulatedOtherComprehensiveIncomeAoci</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>99930303 - Disclosure - Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecuritiesTables</Role>
      <ShortName>Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureSecurities</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>99930403 - Disclosure - Loans and Allowance for Credit Losses on Loans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansTables</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoans</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>99930503 - Disclosure - Loan Servicing (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoanServicingTables</Role>
      <ShortName>Loan Servicing (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureLoanServicing</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>99930603 - Disclosure - Premises and Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosurePremisesAndEquipmentTables</Role>
      <ShortName>Premises and Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosurePremisesAndEquipment</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>99930703 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureLeases</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>99930803 - Disclosure - Goodwill and Other Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureGoodwillAndOtherIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Other Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureGoodwillAndOtherIntangibleAssets</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>99930903 - Disclosure - Deposits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureDepositsTables</Role>
      <ShortName>Deposits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureDeposits</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>99931003 - Disclosure - Borrowing Arrangements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBorrowingArrangementsTables</Role>
      <ShortName>Borrowing Arrangements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureBorrowingArrangements</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>99931103 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxes</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>99931203 - Disclosure - Equity Plan (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureEquityPlanTables</Role>
      <ShortName>Equity Plan (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureEquityPlan</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>99931303 - Disclosure - Benefit Plans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansTables</Role>
      <ShortName>Benefit Plans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlans</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>99931403 - Disclosure - Fair Value (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureFairValueTables</Role>
      <ShortName>Fair Value (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureFairValue</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>99931503 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureCommitmentsAndContingencies</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>99931603 - Disclosure - Shareholders' Equity and Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureShareholdersEquityAndEarningsPerShareTables</Role>
      <ShortName>Shareholders' Equity and Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureShareholdersEquityAndEarningsPerShare</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>99931703 - Disclosure - Capital Requirements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureCapitalRequirementsTables</Role>
      <ShortName>Capital Requirements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureCapitalRequirements</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>99931803 - Disclosure - Revenue Recognition (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureRevenueRecognitionTables</Role>
      <ShortName>Revenue Recognition (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureRevenueRecognition</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>99931903 - Disclosure - Noninterest Expense (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureNoninterestExpenseTables</Role>
      <ShortName>Noninterest Expense (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureNoninterestExpense</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>99932003 - Disclosure - Business Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBusinessSegmentInformationTables</Role>
      <ShortName>Business Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureBusinessSegmentInformation</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>99932103 - Disclosure - Parent Company only Condensed Financial Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureParentCompanyOnlyCondensedFinancialInformationTables</Role>
      <ShortName>Parent Company only Condensed Financial Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureParentCompanyOnlyCondensedFinancialInformation</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>99940101 - Disclosure - Summary of Significant Accounting Policies - Cash and Cash Equivalents (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSummaryOfSignificantAccountingPoliciesCashAndCashEquivalentsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Cash and Cash Equivalents (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>99940102 - Disclosure - Summary of Significant Accounting Policies - Allowance for Credit Losses on Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAllowanceForCreditLossesOnLoansDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Allowance for Credit Losses on Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>99940103 - Disclosure - Summary of Significant Accounting Policies - Premises and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPremisesAndEquipmentDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Premises and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>99940104 - Disclosure - Summary of Significant Accounting Policies - Goodwill and Other Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSummaryOfSignificantAccountingPoliciesGoodwillAndOtherIntangibleAssetsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Goodwill and Other Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>99940105 - Disclosure - Summary of Significant Accounting Policies - Foreclosed Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSummaryOfSignificantAccountingPoliciesForeclosedAssetsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Foreclosed Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>99940106 - Disclosure - Summary of Significant Accounting Policies - Segment Reporting (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSummaryOfSignificantAccountingPoliciesSegmentReportingDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Segment Reporting (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>99940201 - Disclosure - Accumulated Other Comprehensive Income (''AOCI '') - Changes in AOCI by Component (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureAccumulatedOtherComprehensiveIncomeAociChangesInAociByComponentDetails</Role>
      <ShortName>Accumulated Other Comprehensive Income (''AOCI '') - Changes in AOCI by Component (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureAccumulatedOtherComprehensiveIncomeAociTables</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>99940202 - Disclosure - Accumulated Other Comprehensive Income (''AOCI'')- Amount Reclassified from AOCI (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureAccumulatedOtherComprehensiveIncomeAociAmountReclassifiedFromAociDetails</Role>
      <ShortName>Accumulated Other Comprehensive Income (''AOCI'')- Amount Reclassified from AOCI (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureAccumulatedOtherComprehensiveIncomeAociTables</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>99940301 - Disclosure - Securities - Amortized Cost and Estimated Fair Value of Securities - Securities Available-for-sale (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecuritiesAmortizedCostAndEstimatedFairValueOfSecuritiesSecuritiesAvailableForSaleDetails</Role>
      <ShortName>Securities - Amortized Cost and Estimated Fair Value of Securities - Securities Available-for-sale (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>99940302 - Disclosure - Securities - Amortized Cost and Estimated Fair Value of Securities - Securities Held-to-maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecuritiesAmortizedCostAndEstimatedFairValueOfSecuritiesSecuritiesHeldToMaturityDetails</Role>
      <ShortName>Securities - Amortized Cost and Estimated Fair Value of Securities - Securities Held-to-maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>99940303 - Disclosure - Securities - Securities with Unrealized Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecuritiesSecuritiesWithUnrealizedLossesDetails</Role>
      <ShortName>Securities - Securities with Unrealized Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>99940304 - Disclosure - Securities - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecuritiesAdditionalInformationDetails</Role>
      <ShortName>Securities - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>99940305 - Disclosure - Securities - Amortized Cost and Fair Value of Debt Securities by Contractual Maturity - Securities Available-for-sale (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecuritiesAmortizedCostAndFairValueOfDebtSecuritiesByContractualMaturitySecuritiesAvailableForSaleDetails</Role>
      <ShortName>Securities - Amortized Cost and Fair Value of Debt Securities by Contractual Maturity - Securities Available-for-sale (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>99940306 - Disclosure - Securities - Amortized Cost and Fair Value of Debt Securities by Contractual Maturity - Securities Held-to-maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecuritiesAmortizedCostAndFairValueOfDebtSecuritiesByContractualMaturitySecuritiesHeldToMaturityDetails</Role>
      <ShortName>Securities - Amortized Cost and Fair Value of Debt Securities by Contractual Maturity - Securities Held-to-maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>99940307 - Disclosure - Securities - Securities Pledged to Secure Public Deposits and for Other Purposes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecuritiesSecuritiesPledgedToSecurePublicDepositsAndForOtherPurposesDetails</Role>
      <ShortName>Securities - Securities Pledged to Secure Public Deposits and for Other Purposes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>99940308 - Disclosure - Securities - Roll-forward by major security type (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSecuritiesRollForwardByMajorSecurityTypeDetails</Role>
      <ShortName>Securities - Roll-forward by major security type (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>99940401 - Disclosure - Loans and Allowance for Credit Losses on Loans - Loans Balance (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansLoansBalanceDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans - Loans Balance (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>99940402 - Disclosure - Loans and Allowance for Credit Losses on Loans - Changes in the Allowance for Loan Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansChangesInAllowanceForLoanLossesDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans - Changes in the Allowance for Loan Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>99940403 - Disclosure - Loans and Allowance for Credit Losses on Loans - Nonaccrual Status and Loans Past Due Over 90 Days (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansNonaccrualStatusAndLoansPastDueOver90DaysDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans - Nonaccrual Status and Loans Past Due Over 90 Days (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>99940404 - Disclosure - Loans and Allowance for Credit Losses on Loans - Aging of Past Due Loans by Class of Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansAgingOfPastDueLoansByClassOfLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans - Aging of Past Due Loans by Class of Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>99940405 - Disclosure - Loans and Allowance for Credit Losses on Loans - Aging of Past Due Loans by Class of Loans - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansAgingOfPastDueLoansByClassOfLoansAdditionalInformationDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans - Aging of Past Due Loans by Class of Loans - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>99940406 - Disclosure - Loans and Allowance for Credit Losses on Loans - Credit Quality Indicators (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansCreditQualityIndicatorsDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans - Credit Quality Indicators (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>99940407 - Disclosure - Loans and Allowance for Credit Losses on Loans - Gross charge-offs by year of origination and revolving loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansGrossChargeOffsByYearOfOriginationAndRevolvingLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans - Gross charge-offs by year of origination and revolving loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>99940408 - Disclosure - Loans and Allowance for Credit Losses on Loans - Amortized Cost Basis of Collateral-dependent Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansAmortizedCostBasisOfCollateralDependentLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans - Amortized Cost Basis of Collateral-dependent Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>99940409 - Disclosure - Loans and Allowance for Credit Losses on Loans -Loan modification (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansLoanModificationDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses on Loans -Loan modification (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>99940501 - Disclosure - Loan Servicing - SBA Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoanServicingSbaLoansDetails</Role>
      <ShortName>Loan Servicing - SBA Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>99940502 - Disclosure - Loan Servicing - Activity for Loan Servicing Rights (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoanServicingActivityForLoanServicingRightsDetails</Role>
      <ShortName>Loan Servicing - Activity for Loan Servicing Rights (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>99940503 - Disclosure - Loan Servicing - Loan Servicing Rights - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoanServicingLoanServicingRightsAdditionalInformationDetails</Role>
      <ShortName>Loan Servicing - Loan Servicing Rights - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>99940504 - Disclosure - Loan Servicing - Activity for IQ Strip Receivables (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLoanServicingActivityForIqStripReceivablesDetails</Role>
      <ShortName>Loan Servicing - Activity for IQ Strip Receivables (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>99940601 - Disclosure - Premises and Equipment - Premises and Equipment, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosurePremisesAndEquipmentPremisesAndEquipmentNetDetails</Role>
      <ShortName>Premises and Equipment - Premises and Equipment, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>99940602 - Disclosure - Premises and Equipment - Depreciation and Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosurePremisesAndEquipmentDepreciationAndAmortizationExpenseDetails</Role>
      <ShortName>Premises and Equipment - Depreciation and Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>99940701 - Disclosure - Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLeasesDetails</Role>
      <ShortName>Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureLeasesTables</ParentRole>
      <Position>87</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>99940702 - Disclosure - Leases - Maturity Analysis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureLeasesMaturityAnalysisDetails</Role>
      <ShortName>Leases - Maturity Analysis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>99940801 - Disclosure - Goodwill and Other Intangible Assets - Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureGoodwillAndOtherIntangibleAssetsGoodwillDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>99940802 - Disclosure - Goodwill and Other Intangible Assets - Other Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureGoodwillAndOtherIntangibleAssetsOtherIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Other Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>99940803 - Disclosure - Goodwill and Other Intangible Assets - Estimated Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureGoodwillAndOtherIntangibleAssetsEstimatedAmortizationExpenseDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Estimated Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>99940804 - Disclosure - Goodwill and Other Intangible Assets - Impairment of Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureGoodwillAndOtherIntangibleAssetsImpairmentOfIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Impairment of Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>99940901 - Disclosure - Deposits - Scheduled Maturities of all Time Deposits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureDepositsScheduledMaturitiesOfAllTimeDepositsDetails</Role>
      <ShortName>Deposits - Scheduled Maturities of all Time Deposits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>99940902 - Disclosure - Deposits - Time Deposits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureDepositsTimeDepositsDetails</Role>
      <ShortName>Deposits - Time Deposits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>99940903 - Disclosure - Deposits - ICS/CDARS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureDepositsIcsCdarsDetails</Role>
      <ShortName>Deposits - ICS/CDARS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>99940904 - Disclosure - Deposits - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureDepositsAdditionalInformationDetails</Role>
      <ShortName>Deposits - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>99941001 - Disclosure - Borrowing Arrangements - Collateral value of loans and securities pledged (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBorrowingArrangementsCollateralValueOfLoansAndSecuritiesPledgedDetails</Role>
      <ShortName>Borrowing Arrangements - Collateral value of loans and securities pledged (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>99941002 - Disclosure - Borrowing Arrangements - Securities Sold under Repurchase Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBorrowingArrangementsSecuritiesSoldUnderRepurchaseAgreementsDetails</Role>
      <ShortName>Borrowing Arrangements - Securities Sold under Repurchase Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>99941003 - Disclosure - Borrowing Arrangements - Subordinated Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBorrowingArrangementsSubordinatedDebtDetails</Role>
      <ShortName>Borrowing Arrangements - Subordinated Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>99</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>99941101 - Disclosure - Income Taxes - Income Tax (Benefit) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxesIncomeTaxBenefitDetails</Role>
      <ShortName>Income Taxes - Income Tax (Benefit) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>100</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>99941102 - Disclosure - Income Taxes - Effective Tax Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxesEffectiveTaxRateDetails</Role>
      <ShortName>Income Taxes - Effective Tax Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>101</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>99941103 - Disclosure - Income Taxes - Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails</Role>
      <ShortName>Income Taxes - Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>102</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>99941104 - Disclosure - Income Taxes - Operating Loss Carryforward (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxesOperatingLossCarryforwardDetails</Role>
      <ShortName>Income Taxes - Operating Loss Carryforward (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>103</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>99941105 - Disclosure - Income Taxes - Carry Amounts of the Low Income Housing Investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxesCarryAmountsOfLowIncomeHousingInvestmentsDetails</Role>
      <ShortName>Income Taxes - Carry Amounts of the Low Income Housing Investments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>104</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>99941106 - Disclosure - Income Taxes - Future Commitments of the Low Income Housing Investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxesFutureCommitmentsOfLowIncomeHousingInvestmentsDetails</Role>
      <ShortName>Income Taxes - Future Commitments of the Low Income Housing Investments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>105</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>99941107 - Disclosure - Income Taxes - Components of Low Income Housing Investment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureIncomeTaxesComponentsOfLowIncomeHousingInvestmentDetails</Role>
      <ShortName>Income Taxes - Components of Low Income Housing Investment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>106</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>99941201 - Disclosure - Equity Plan - General Disclosures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureEquityPlanGeneralDisclosuresDetails</Role>
      <ShortName>Equity Plan - General Disclosures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>107</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>99941202 - Disclosure - Equity Plan - Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureEquityPlanStockOptionActivityDetails</Role>
      <ShortName>Equity Plan - Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>99941203 - Disclosure - Equity Plan - Information Related to the Equity Plans for each of the Last Three Years (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureEquityPlanInformationRelatedToEquityPlansForEachOfLastThreeYearsDetails</Role>
      <ShortName>Equity Plan - Information Related to the Equity Plans for each of the Last Three Years (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>109</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>99941204 - Disclosure - Equity Plan - Unrecognized Compensation Cost -Nonvested Stock Options (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureEquityPlanUnrecognizedCompensationCostNonvestedStockOptionsDetails</Role>
      <ShortName>Equity Plan - Unrecognized Compensation Cost -Nonvested Stock Options (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>99941205 - Disclosure - Equity Plan - Assumptions Used to Estimate Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureEquityPlanAssumptionsUsedToEstimateFairValueDetails</Role>
      <ShortName>Equity Plan - Assumptions Used to Estimate Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>111</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>99941206 - Disclosure - Equity Plan - Restricted Stock Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureEquityPlanRestrictedStockActivityDetails</Role>
      <ShortName>Equity Plan - Restricted Stock Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>112</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>99941207 - Disclosure - Equity Plan - Unrecognized Compensation Cost - Nonvested Restricted Stock Awards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureEquityPlanUnrecognizedCompensationCostNonvestedRestrictedStockAwardsDetails</Role>
      <ShortName>Equity Plan - Unrecognized Compensation Cost - Nonvested Restricted Stock Awards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>113</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>99941301 - Disclosure - Benefit Plans - 401(k) Savings Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlans401KSavingsPlanDetails</Role>
      <ShortName>Benefit Plans - 401(k) Savings Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>114</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>99941302 - Disclosure - Benefit Plans - Employee Stock Ownership Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansEmployeeStockOwnershipPlanDetails</Role>
      <ShortName>Benefit Plans - Employee Stock Ownership Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>115</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>99941303 - Disclosure - Benefit Plans - Deferred Compensation Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansDeferredCompensationPlanDetails</Role>
      <ShortName>Benefit Plans - Deferred Compensation Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>116</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>99941304 - Disclosure - Benefit Plans - Defined Benefit Plans - Nonqualified Defined Benefit Pension Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansDefinedBenefitPlansNonqualifiedDefinedBenefitPensionPlanDetails</Role>
      <ShortName>Benefit Plans - Defined Benefit Plans - Nonqualified Defined Benefit Pension Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>117</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>99941305 - Disclosure - Benefit Plans - Defined Benefit Plans - Change in Projected Benefit Obligation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansDefinedBenefitPlansChangeInProjectedBenefitObligationDetails</Role>
      <ShortName>Benefit Plans - Defined Benefit Plans - Change in Projected Benefit Obligation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>118</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R119.htm</HtmlFileName>
      <LongName>99941306 - Disclosure - Benefit Plans - Defined Benefit Plans - Amounts Recognized in Accumulated Other Comprehensive Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansDefinedBenefitPlansAmountsRecognizedInAccumulatedOtherComprehensiveLossDetails</Role>
      <ShortName>Benefit Plans - Defined Benefit Plans - Amounts Recognized in Accumulated Other Comprehensive Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>119</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R120.htm</HtmlFileName>
      <LongName>99941307 - Disclosure - Benefit Plans - Defined Benefit Plans - Weighted-average Assumptions Used to Determine the Benefit Obligation at Year-end (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansDefinedBenefitPlansWeightedAverageAssumptionsUsedToDetermineBenefitObligationAtYearEndDetails</Role>
      <ShortName>Benefit Plans - Defined Benefit Plans - Weighted-average Assumptions Used to Determine the Benefit Obligation at Year-end (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>120</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R121.htm</HtmlFileName>
      <LongName>99941308 - Disclosure - Benefit Plans - Defined Benefit Plans - Estimated Benefit Payments over the Next Ten Years (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansDefinedBenefitPlansEstimatedBenefitPaymentsOverNextTenYearsDetails</Role>
      <ShortName>Benefit Plans - Defined Benefit Plans - Estimated Benefit Payments over the Next Ten Years (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>121</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R122.htm</HtmlFileName>
      <LongName>99941309 - Disclosure - Benefit Plans - Defined Benefit Plans - Components of Pension Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansDefinedBenefitPlansComponentsOfPensionCostDetails</Role>
      <ShortName>Benefit Plans - Defined Benefit Plans - Components of Pension Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>122</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R123.htm</HtmlFileName>
      <LongName>99941310 - Disclosure - Benefit Plans - Defined Benefit Plans - Estimated Net Actuarial Loss and Prior Service Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansDefinedBenefitPlansEstimatedNetActuarialLossAndPriorServiceCostDetails</Role>
      <ShortName>Benefit Plans - Defined Benefit Plans - Estimated Net Actuarial Loss and Prior Service Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>123</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R124.htm</HtmlFileName>
      <LongName>99941311 - Disclosure - Benefit Plans - Defined Benefit Plans - Weighted-average Assumptions Used to Determine Net Periodic Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBenefitPlansDefinedBenefitPlansWeightedAverageAssumptionsUsedToDetermineNetPeriodicCostDetails</Role>
      <ShortName>Benefit Plans - Defined Benefit Plans - Weighted-average Assumptions Used to Determine Net Periodic Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>124</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R125.htm</HtmlFileName>
      <LongName>99941401 - Disclosure - Fair Value - Financial Assets and Liabilities Measured on a Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureFairValueFinancialAssetsAndLiabilitiesMeasuredOnRecurringBasisDetails</Role>
      <ShortName>Fair Value - Financial Assets and Liabilities Measured on a Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>125</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R126.htm</HtmlFileName>
      <LongName>99941402 - Disclosure - Fair Value - Impaired Loans Held-for-investment - Additional Disclosures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureFairValueImpairedLoansHeldForInvestmentAdditionalDisclosuresDetails</Role>
      <ShortName>Fair Value - Impaired Loans Held-for-investment - Additional Disclosures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>126</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R127.htm</HtmlFileName>
      <LongName>99941403 - Disclosure - Fair Value - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureFairValueCarryingAmountsAndEstimatedFairValuesOfFinancialInstrumentsDetails</Role>
      <ShortName>Fair Value - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>127</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R128.htm</HtmlFileName>
      <LongName>99941501 - Disclosure - Commitments and Contingencies - Financial Instruments with Off-Balance Sheet Risk (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureCommitmentsAndContingenciesFinancialInstrumentsWithOffBalanceSheetRiskDetails</Role>
      <ShortName>Commitments and Contingencies - Financial Instruments with Off-Balance Sheet Risk (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>128</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R129.htm</HtmlFileName>
      <LongName>99941601 - Disclosure - Shareholders' Equity and Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureShareholdersEquityAndEarningsPerShareDetails</Role>
      <ShortName>Shareholders' Equity and Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureShareholdersEquityAndEarningsPerShareTables</ParentRole>
      <Position>129</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R130.htm</HtmlFileName>
      <LongName>99941701 - Disclosure - Capital Requirements - Tabular Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureCapitalRequirementsTabularDisclosureDetails</Role>
      <ShortName>Capital Requirements - Tabular Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>130</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R131.htm</HtmlFileName>
      <LongName>99941702 - Disclosure - Capital Requirements - Dividends to Parent (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureCapitalRequirementsDividendsToParentDetails</Role>
      <ShortName>Capital Requirements - Dividends to Parent (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>131</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R132.htm</HtmlFileName>
      <LongName>99941801 - Disclosure - Revenue Recognition (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureRevenueRecognitionDetails</Role>
      <ShortName>Revenue Recognition (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureRevenueRecognitionTables</ParentRole>
      <Position>132</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R133.htm</HtmlFileName>
      <LongName>99941901 - Disclosure - Noninterest Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureNoninterestExpenseDetails</Role>
      <ShortName>Noninterest Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureNoninterestExpenseTables</ParentRole>
      <Position>133</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R134.htm</HtmlFileName>
      <LongName>99942001 - Disclosure - Business Segment Information - Business Segments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBusinessSegmentInformationBusinessSegmentsDetails</Role>
      <ShortName>Business Segment Information - Business Segments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>134</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R135.htm</HtmlFileName>
      <LongName>99942002 - Disclosure - Business Segment Information - Operating Statements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureBusinessSegmentInformationOperatingStatementsDetails</Role>
      <ShortName>Business Segment Information - Operating Statements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>135</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R136.htm</HtmlFileName>
      <LongName>99942101 - Disclosure - Parent Company only Condensed Financial Information - Balance Sheets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureParentCompanyOnlyCondensedFinancialInformationBalanceSheetsDetails</Role>
      <ShortName>Parent Company only Condensed Financial Information - Balance Sheets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>136</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R137.htm</HtmlFileName>
      <LongName>99942102 - Disclosure - Parent Company only Condensed Financial Information - Statements of Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureParentCompanyOnlyCondensedFinancialInformationStatementsOfIncomeDetails</Role>
      <ShortName>Parent Company only Condensed Financial Information - Statements of Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>137</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R138.htm</HtmlFileName>
      <LongName>99942103 - Disclosure - Parent Company only Condensed Financial Information - Statements of Cash Flows (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureParentCompanyOnlyCondensedFinancialInformationStatementsOfCashFlowsDetails</Role>
      <ShortName>Parent Company only Condensed Financial Information - Statements of Cash Flows (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>138</Position>
    </Report>
    <Report instance="htbk-20241231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R139.htm</HtmlFileName>
      <LongName>99942201 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.heritagecommercecorp.com/role/DisclosureSubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.heritagecommercecorp.com/role/DisclosureSubsequentEvents</ParentRole>
      <Position>139</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>htbk-20241231.xsd</File>
    <File>htbk-20241231_cal.xml</File>
    <File>htbk-20241231_def.xml</File>
    <File>htbk-20241231_lab.xml</File>
    <File>htbk-20241231_pre.xml</File>
    <File doctype="10-K" isDefinitelyFs="true" isUsgaap="true" original="htbk-20241231x10k.htm">htbk-20241231x10k.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>htbk-20241231x10k003.jpg</File>
    <File>htbk-20241231x10k004.jpg</File>
    <File>htbk-20241231x10k005.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="4">http://fasb.org/srt/2024</BaseTaxonomy>
    <BaseTaxonomy items="2019">http://fasb.org/us-gaap/2024</BaseTaxonomy>
    <BaseTaxonomy items="15">http://xbrl.sec.gov/cyd/2024</BaseTaxonomy>
    <BaseTaxonomy items="37">http://xbrl.sec.gov/dei/2024</BaseTaxonomy>
    <BaseTaxonomy items="5">http://xbrl.sec.gov/ecd/2024</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
