<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>557</ContextCount>
  <ElementCount>684</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>91</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00090 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00100 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00105 - Statement - Consolidated Balance Sheets (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/StatementConsolidatedBalanceSheetsParentheticals</Role>
      <ShortName>Consolidated Balance Sheets (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00200 - Statement - Consolidated Statements of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/StatementConsolidatedStatementsOfIncome</Role>
      <ShortName>Consolidated Statements of Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="hwbk-20191231.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://hawthornbancshares.com/role/StatementConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statements of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>00400 - Statement - Consolidated Statements of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/StatementConsolidatedStatementsOfStockholdersEquity</Role>
      <ShortName>Consolidated Statements of Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>00405 - Statement - Consolidated Statements of Stockholders' Equity (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/StatementConsolidatedStatementsOfStockholdersEquityParentheticals</Role>
      <ShortName>Consolidated Statements of Stockholders' Equity (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>00500 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>10101 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>10201 - Disclosure - Loans and Allowance for Loan Losses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLosses</Role>
      <ShortName>Loans and Allowance for Loan Losses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>10301 - Disclosure - Other Real Estate and Repossessed Assets Acquired in Settlement of Loans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureOtherRealEstateAndRepossessedAssetsAcquiredInSettlementOfLoans</Role>
      <ShortName>Other Real Estate and Repossessed Assets Acquired in Settlement of Loans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>10401 - Disclosure - Investment Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureInvestmentSecurities</Role>
      <ShortName>Investment Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>10501 - Disclosure - Premises and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosurePremisesAndEquipment</Role>
      <ShortName>Premises and Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>10601 - Disclosure - Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIntangibleAssets</Role>
      <ShortName>Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>10701 - Disclosure - Deposits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureDeposits</Role>
      <ShortName>Deposits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>10801 - Disclosure - Federal funds purchased and securities sold under agreements to repurchase</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase</Role>
      <ShortName>Federal funds purchased and securities sold under agreements to repurchase</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>10901 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLeases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>11001 - Disclosure - Borrowings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureBorrowings</Role>
      <ShortName>Borrowings</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>11101 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>11201 - Disclosure - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureStockholdersEquity</Role>
      <ShortName>Stockholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>11301 - Disclosure - Employee Benefit Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlans</Role>
      <ShortName>Employee Benefit Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>11401 - Disclosure - Stock Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureStockCompensation</Role>
      <ShortName>Stock Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>11501 - Disclosure - Earnings per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEarningsPerShare</Role>
      <ShortName>Earnings per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>11601 - Disclosure - Capital Requirements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCapitalRequirements</Role>
      <ShortName>Capital Requirements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>11701 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>11801 - Disclosure - Fair Value of Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueOfFinancialInstruments</Role>
      <ShortName>Fair Value of Financial Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>11901 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>12001 - Disclosure - Revenue Recognition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureRevenueRecognition</Role>
      <ShortName>Revenue Recognition</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>12101 - Disclosure - Condensed Financial Information of the Parent Company Only</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCondensedFinancialInformationOfParentCompanyOnly</Role>
      <ShortName>Condensed Financial Information of the Parent Company Only</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>12201 - Disclosure - Quarterly Financial Information (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureQuarterlyFinancialInformationUnaudited</Role>
      <ShortName>Quarterly Financial Information (Unaudited)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>20102 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>30203 - Disclosure - Loans and Allowance for Loan Losses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesTables</Role>
      <ShortName>Loans and Allowance for Loan Losses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLosses</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>30303 - Disclosure - Other Real Estate and Repossessed Assets Acquired in Settlement of Loans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureOtherRealEstateAndRepossessedAssetsAcquiredInSettlementOfLoansTables</Role>
      <ShortName>Other Real Estate and Repossessed Assets Acquired in Settlement of Loans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureOtherRealEstateAndRepossessedAssetsAcquiredInSettlementOfLoans</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>30403 - Disclosure - Investment Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureInvestmentSecuritiesTables</Role>
      <ShortName>Investment Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureInvestmentSecurities</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>30503 - Disclosure - Premises and Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosurePremisesAndEquipmentTables</Role>
      <ShortName>Premises and Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosurePremisesAndEquipment</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>30603 - Disclosure - Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIntangibleAssetsTables</Role>
      <ShortName>Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureIntangibleAssets</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>30703 - Disclosure - Deposits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureDepositsTables</Role>
      <ShortName>Deposits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureDeposits</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>30803 - Disclosure - Federal funds purchased and securities sold under agreements to repurchase (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseTables</Role>
      <ShortName>Federal funds purchased and securities sold under agreements to repurchase (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>30903 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureLeases</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>31003 - Disclosure - Borrowings (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureBorrowingsTables</Role>
      <ShortName>Borrowings (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureBorrowings</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>31103 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureIncomeTaxes</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>31203 - Disclosure - Stockholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureStockholdersEquityTables</Role>
      <ShortName>Stockholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureStockholdersEquity</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>31303 - Disclosure - Employee Benefit Plans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansTables</Role>
      <ShortName>Employee Benefit Plans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlans</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>31403 - Disclosure - Stock Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureStockCompensationTables</Role>
      <ShortName>Stock Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureStockCompensation</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>31503 - Disclosure - Earnings per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEarningsPerShareTables</Role>
      <ShortName>Earnings per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureEarningsPerShare</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>31603 - Disclosure - Capital Requirements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCapitalRequirementsTables</Role>
      <ShortName>Capital Requirements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureCapitalRequirements</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>31703 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureFairValueMeasurements</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>31803 - Disclosure - Fair Value of Financial Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueOfFinancialInstrumentsTables</Role>
      <ShortName>Fair Value of Financial Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureFairValueOfFinancialInstruments</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>31903 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureCommitmentsAndContingencies</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>32103 - Disclosure - Condensed Financial Information of the Parent Company Only (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCondensedFinancialInformationOfParentCompanyOnlyTables</Role>
      <ShortName>Condensed Financial Information of the Parent Company Only (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureCondensedFinancialInformationOfParentCompanyOnly</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>32203 - Disclosure - Quarterly Financial Information (Unaudited) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureQuarterlyFinancialInformationUnauditedTables</Role>
      <ShortName>Quarterly Financial Information (Unaudited) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureQuarterlyFinancialInformationUnaudited</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>40101 - Disclosure - Summary of Significant Accounting Policies - Other (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureSummaryOfSignificantAccountingPoliciesOtherDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Other (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>40102 - Disclosure - Summary of Significant Accounting Policies - Recent Transactions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureSummaryOfSignificantAccountingPoliciesRecentTransactionsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Recent Transactions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>40103 - Disclosure - Summary of Significant Accounting Policies - New Accounting Principles (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureSummaryOfSignificantAccountingPoliciesNewAccountingPrinciplesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - New Accounting Principles (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>40201 - Disclosure - Loans and Allowance for Loan Losses - Summary of Loans by Major Class (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesSummaryOfLoansByMajorClassDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Summary of Loans by Major Class (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>40202 - Disclosure - Loans and Allowance for Loan Losses - Loans Pledged (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesLoansPledgedDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Loans Pledged (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>40203 - Disclosure - Loans and Allowance for Loan Losses - Related Parties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesRelatedPartiesDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Related Parties (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>40204 - Disclosure - Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesAllowanceForLoanLossesDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>40205 - Disclosure - Loans and Allowance for Loan Losses - Impairment Methodology (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesImpairmentMethodologyDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Impairment Methodology (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>40206 - Disclosure - Loans and Allowance for Loan Losses - Impaired Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesImpairedLoansDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Impaired Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>40207 - Disclosure - Loans and Allowance for Loan Losses - Categories of Impaired Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesCategoriesOfImpairedLoansDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Categories of Impaired Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>40208 - Disclosure - Loans and Allowance for Loan Losses - Additional information about Impaired Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesAdditionalInformationAboutImpairedLoansDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Additional information about Impaired Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>40209 - Disclosure - Loans and Allowance for Loan Losses - Average Recorded Investment and Interest Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesAverageRecordedInvestmentAndInterestIncomeDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Average Recorded Investment and Interest Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>40210 - Disclosure - Loans and Allowance for Loan Losses - Past Due and Non-accrual Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Past Due and Non-accrual Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>40211 - Disclosure - Loans and Allowance for Loan Losses - Credit Quality (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesCreditQualityDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Credit Quality (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>40212 - Disclosure - Loans and Allowance for Loan Losses - Troubled Debt Restructurings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLoansAndAllowanceForLoanLossesTroubledDebtRestructuringsDetails</Role>
      <ShortName>Loans and Allowance for Loan Losses - Troubled Debt Restructurings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>40301 - Disclosure - Other Real Estate and Repossessed Assets Acquired in Settlement of Loans - Summary (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureOtherRealEstateAndRepossessedAssetsAcquiredInSettlementOfLoansSummaryDetails</Role>
      <ShortName>Other Real Estate and Repossessed Assets Acquired in Settlement of Loans - Summary (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureOtherRealEstateAndRepossessedAssetsAcquiredInSettlementOfLoansTables</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>40302 - Disclosure - Other Real Estate and Repossessed Assets Acquired in Settlement of Loans - Changes in Net Carrying Amount (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureOtherRealEstateAndRepossessedAssetsAcquiredInSettlementOfLoansChangesInNetCarryingAmountDetails</Role>
      <ShortName>Other Real Estate and Repossessed Assets Acquired in Settlement of Loans - Changes in Net Carrying Amount (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>40303 - Disclosure - Other Real Estate and Repossessed Assets Acquired in Settlement of Loans - Foreclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureOtherRealEstateAndRepossessedAssetsAcquiredInSettlementOfLoansForeclosureDetails</Role>
      <ShortName>Other Real Estate and Repossessed Assets Acquired in Settlement of Loans - Foreclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureOtherRealEstateAndRepossessedAssetsAcquiredInSettlementOfLoansTables</ParentRole>
      <Position>69</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>40304 - Disclosure - Other Real Estate and Repossessed Assets Acquired in Settlement of Loans - Valuation Allowance (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureOtherRealEstateAndRepossessedAssetsAcquiredInSettlementOfLoansValuationAllowanceDetails</Role>
      <ShortName>Other Real Estate and Repossessed Assets Acquired in Settlement of Loans - Valuation Allowance (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>40401 - Disclosure - Investment Securities - Amortized Costs, Gains and Losses, Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureInvestmentSecuritiesAmortizedCostsGainsAndLossesFairValueDetails</Role>
      <ShortName>Investment Securities - Amortized Costs, Gains and Losses, Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>40402 - Disclosure - Investment Securities - Securities Pledged (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureInvestmentSecuritiesSecuritiesPledgedDetails</Role>
      <ShortName>Investment Securities - Securities Pledged (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>40403 - Disclosure - Investment Securities - Amortized Cost and Fair Value by Contractual Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueByContractualMaturityDetails</Role>
      <ShortName>Investment Securities - Amortized Cost and Fair Value by Contractual Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>40404 - Disclosure - Investment Securities - Other Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureInvestmentSecuritiesOtherSecuritiesDetails</Role>
      <ShortName>Investment Securities - Other Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>40405 - Disclosure - Investment Securities - Unrealized Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureInvestmentSecuritiesUnrealizedLossesDetails</Role>
      <ShortName>Investment Securities - Unrealized Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>40406 - Disclosure - Investment Securities - Other (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureInvestmentSecuritiesOtherDetails</Role>
      <ShortName>Investment Securities - Other (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>40407 - Disclosure - Investment Securities - Components of Investment Securities Gains and Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureInvestmentSecuritiesComponentsOfInvestmentSecuritiesGainsAndLossesDetails</Role>
      <ShortName>Investment Securities - Components of Investment Securities Gains and Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>40501 - Disclosure - Premises and Equipment - Summary (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosurePremisesAndEquipmentSummaryDetails</Role>
      <ShortName>Premises and Equipment - Summary (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>40502 - Disclosure - Premises and Equipment - Depreciation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosurePremisesAndEquipmentDepreciationDetails</Role>
      <ShortName>Premises and Equipment - Depreciation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>40601 - Disclosure - Intangible Assets - Mortgage Servicing Rights (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIntangibleAssetsMortgageServicingRightsDetails</Role>
      <ShortName>Intangible Assets - Mortgage Servicing Rights (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>40602 - Disclosure - Intangible Assets - Changes in Mortgage Servicing Rights (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIntangibleAssetsChangesInMortgageServicingRightsDetails</Role>
      <ShortName>Intangible Assets - Changes in Mortgage Servicing Rights (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>40603 - Disclosure - Intangible Assets - FV Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIntangibleAssetsFvAssumptionsDetails</Role>
      <ShortName>Intangible Assets - FV Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>40701 - Disclosure - Deposits - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureDepositsNarrativeDetails</Role>
      <ShortName>Deposits - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>40702 - Disclosure - Deposits - Maturities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureDepositsMaturitiesDetails</Role>
      <ShortName>Deposits - Maturities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>40801 - Disclosure - Federal funds purchased and securities sold under agreements to repurchase - Federal Funds and Repurchase Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseFederalFundsAndRepurchaseAgreementsDetails</Role>
      <ShortName>Federal funds purchased and securities sold under agreements to repurchase - Federal Funds and Repurchase Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>40802 - Disclosure - Federal funds purchased and securities sold under agreements to repurchase - Repurchase Agreements - Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseRepurchaseAgreementsMaturityDetails</Role>
      <ShortName>Federal funds purchased and securities sold under agreements to repurchase - Repurchase Agreements - Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>40803 - Disclosure - Federal funds purchased and securities sold under agreements to repurchase - Secured and Unsecured (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseSecuredAndUnsecuredDetails</Role>
      <ShortName>Federal funds purchased and securities sold under agreements to repurchase - Secured and Unsecured (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>40901 - Disclosure - Leases - Other (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLeasesOtherDetails</Role>
      <ShortName>Leases - Other (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>40902 - Disclosure - Leases - Maturities of remaining operating lease liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureLeasesMaturitiesOfRemainingOperatingLeaseLiabilitiesDetails</Role>
      <ShortName>Leases - Maturities of remaining operating lease liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>41001 - Disclosure - Borrowings - FHLB and Other (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureBorrowingsFhlbAndOtherDetails</Role>
      <ShortName>Borrowings - FHLB and Other (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>41002 - Disclosure - Borrowings - Trust Preferred Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureBorrowingsTrustPreferredSecuritiesDetails</Role>
      <ShortName>Borrowings - Trust Preferred Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>41101 - Disclosure - Income Taxes - Components of Income Tax Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIncomeTaxesComponentsOfIncomeTaxExpenseDetails</Role>
      <ShortName>Income Taxes - Components of Income Tax Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>41102 - Disclosure - Income Taxes - Income Tax Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIncomeTaxesIncomeTaxReconciliationDetails</Role>
      <ShortName>Income Taxes - Income Tax Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>41103 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureIncomeTaxesTables</ParentRole>
      <Position>94</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>41104 - Disclosure - Income Taxes - Deferred Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureIncomeTaxesDeferredTaxesDetails</Role>
      <ShortName>Income Taxes - Deferred Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>41201 - Disclosure - Stockholders' Equity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureStockholdersEquityDetails</Role>
      <ShortName>Stockholders' Equity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureStockholdersEquityTables</ParentRole>
      <Position>96</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>41301 - Disclosure - Employee Benefit Plans - Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansExpenseDetails</Role>
      <ShortName>Employee Benefit Plans - Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>41302 - Disclosure - Employee Benefit Plans - Change in PBO (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansChangeInPboDetails</Role>
      <ShortName>Employee Benefit Plans - Change in PBO (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>41303 - Disclosure - Employee Benefit Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansDetails</Role>
      <ShortName>Employee Benefit Plans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansTables</ParentRole>
      <Position>99</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>41304 - Disclosure - Employee Benefit Plans - Net Pension Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansNetPensionCostDetails</Role>
      <ShortName>Employee Benefit Plans - Net Pension Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>100</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>41305 - Disclosure - Employee Benefit Plans - Accumulated and Other Comprehensive Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansAccumulatedAndOtherComprehensiveLossDetails</Role>
      <ShortName>Employee Benefit Plans - Accumulated and Other Comprehensive Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>101</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>41306 - Disclosure - Employee Benefit Plans - Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansAssumptionsDetails</Role>
      <ShortName>Employee Benefit Plans - Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>102</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>41307 - Disclosure - Employee Benefit Plans - FV of Plan Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansFvOfPlanAssetsDetails</Role>
      <ShortName>Employee Benefit Plans - FV of Plan Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>103</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>41308 - Disclosure - Employee Benefit Plans - Future Benefit Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEmployeeBenefitPlansFutureBenefitPaymentsDetails</Role>
      <ShortName>Employee Benefit Plans - Future Benefit Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>104</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>41401 - Disclosure - Stock Compensation - Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureStockCompensationStockOptionActivityDetails</Role>
      <ShortName>Stock Compensation - Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>105</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>41402 - Disclosure - Stock Compensation - Other (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureStockCompensationOtherDetails</Role>
      <ShortName>Stock Compensation - Other (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>106</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>41501 - Disclosure - Earnings per Share - Stock Dividend (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEarningsPerShareStockDividendDetails</Role>
      <ShortName>Earnings per Share - Stock Dividend (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>107</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>41502 - Disclosure - Earnings per Share - Components (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEarningsPerShareComponentsDetails</Role>
      <ShortName>Earnings per Share - Components (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>41503 - Disclosure - Earnings per Share - Anti-dilutive (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEarningsPerShareAntiDilutiveDetails</Role>
      <ShortName>Earnings per Share - Anti-dilutive (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>109</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>41504 - Disclosure - Earnings per Share - Repurchase Program (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureEarningsPerShareRepurchaseProgramDetails</Role>
      <ShortName>Earnings per Share - Repurchase Program (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>41601 - Disclosure - Capital Requirements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCapitalRequirementsDetails</Role>
      <ShortName>Capital Requirements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureCapitalRequirementsTables</ParentRole>
      <Position>111</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>41701 - Disclosure - Fair Value Measurements - Transfers Between Levels (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueMeasurementsTransfersBetweenLevelsDetails</Role>
      <ShortName>Fair Value Measurements - Transfers Between Levels (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>112</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>41702 - Disclosure - Fair Value Measurements - Mortgage Servicing Rights - Summary (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueMeasurementsMortgageServicingRightsSummaryDetails</Role>
      <ShortName>Fair Value Measurements - Mortgage Servicing Rights - Summary (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>113</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>41703 - Disclosure - Fair Value Measurements - Mortgage Servicing Rights - Level 3 (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueMeasurementsMortgageServicingRightsLevel3Details</Role>
      <ShortName>Fair Value Measurements - Mortgage Servicing Rights - Level 3 (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>114</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>41704 - Disclosure - Fair Value Measurements - Mortgage Servicing Rights - Other (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueMeasurementsMortgageServicingRightsOtherDetails</Role>
      <ShortName>Fair Value Measurements - Mortgage Servicing Rights - Other (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>115</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>41705 - Disclosure - Fair Value Measurements - Other Real Estate Owned and Repossessed Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueMeasurementsOtherRealEstateOwnedAndRepossessedAssetsDetails</Role>
      <ShortName>Fair Value Measurements - Other Real Estate Owned and Repossessed Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>116</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>41801 - Disclosure - Fair Value of Financial Instruments - Summary (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureFairValueOfFinancialInstrumentsSummaryDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Summary (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>117</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>41901 - Disclosure - Commitments and Contingencies - Contractual Amounts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCommitmentsAndContingenciesContractualAmountsDetails</Role>
      <ShortName>Commitments and Contingencies - Contractual Amounts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>118</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R119.htm</HtmlFileName>
      <LongName>41902 - Disclosure - Commitments and Contingencies - Other (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCommitmentsAndContingenciesOtherDetails</Role>
      <ShortName>Commitments and Contingencies - Other (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>119</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R120.htm</HtmlFileName>
      <LongName>42101 - Disclosure - Condensed Financial Information of the Parent Company Only - Balance Sheets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCondensedFinancialInformationOfParentCompanyOnlyBalanceSheetsDetails</Role>
      <ShortName>Condensed Financial Information of the Parent Company Only - Balance Sheets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>120</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R121.htm</HtmlFileName>
      <LongName>42102 - Disclosure - Condensed Financial Information of the Parent Company Only - Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCondensedFinancialInformationOfParentCompanyOnlyIncomeDetails</Role>
      <ShortName>Condensed Financial Information of the Parent Company Only - Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureCondensedFinancialInformationOfParentCompanyOnlyTables</ParentRole>
      <Position>121</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R122.htm</HtmlFileName>
      <LongName>42103 - Disclosure - Condensed Financial Information of the Parent Company Only - Cash Flows (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureCondensedFinancialInformationOfParentCompanyOnlyCashFlowsDetails</Role>
      <ShortName>Condensed Financial Information of the Parent Company Only - Cash Flows (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureCondensedFinancialInformationOfParentCompanyOnlyTables</ParentRole>
      <Position>122</Position>
    </Report>
    <Report instance="hwbk-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R123.htm</HtmlFileName>
      <LongName>42201 - Disclosure - Quarterly Financial Information (Unaudited) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://hawthornbancshares.com/role/DisclosureQuarterlyFinancialInformationUnauditedDetails</Role>
      <ShortName>Quarterly Financial Information (Unaudited) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://hawthornbancshares.com/role/DisclosureQuarterlyFinancialInformationUnauditedTables</ParentRole>
      <Position>123</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>hwbk-20191231.xml</File>
    <File>hwbk-20191231.xsd</File>
    <File>hwbk-20191231_cal.xml</File>
    <File>hwbk-20191231_def.xml</File>
    <File>hwbk-20191231_lab.xml</File>
    <File>hwbk-20191231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://fasb.org/us-gaap/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2019-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
