<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>262</ContextCount>
  <ElementCount>300</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>55</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>8</UnitCount>
  <MyReports>
    <Report instance="tmb-20241231x10q.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.monroefederal.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>995200100 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="tmb-20241231x10q.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.monroefederal.com/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>995200200 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/StatementConsolidatedStatementsOfOperations</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>995200300 - Statement - Consolidated Statements of Comprehensive Income (Loss)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss</Role>
      <ShortName>Consolidated Statements of Comprehensive Income (Loss)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>995200400 - Statement - Consolidated Statements of Changes in Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity</Role>
      <ShortName>Consolidated Statements of Changes in Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>995200500 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>995210101 - Disclosure - Nature of Operations and Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>995210201 - Disclosure - Investment Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureInvestmentSecurities</Role>
      <ShortName>Investment Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995210301 - Disclosure - Loans and Allowance for Credit Losses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLosses</Role>
      <ShortName>Loans and Allowance for Credit Losses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995210401 - Disclosure - Time Deposits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureTimeDeposits</Role>
      <ShortName>Time Deposits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995210501 - Disclosure - Borrowings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureBorrowings</Role>
      <ShortName>Borrowings</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995210601 - Disclosure - Employee Stock Option Plan (ESOP)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureEmployeeStockOptionPlanEsop</Role>
      <ShortName>Employee Stock Option Plan (ESOP)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995210701 - Disclosure - Earnings (Loss) Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureEarningsLossPerShare</Role>
      <ShortName>Earnings (Loss) Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995210801 - Disclosure - Regulatory Matters</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureRegulatoryMatters</Role>
      <ShortName>Regulatory Matters</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995210901 - Disclosure - Disclosures about Fair Value of Assets and Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureDisclosuresAboutFairValueOfAssetsAndLiabilities</Role>
      <ShortName>Disclosures about Fair Value of Assets and Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.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>17</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.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>18</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>99920102 - Disclosure - Nature of Operations and Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>99930103 - Disclosure - Nature of Operations and Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>99930203 - Disclosure - Investment Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureInvestmentSecuritiesTables</Role>
      <ShortName>Investment Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureInvestmentSecurities</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>99930303 - Disclosure - Loans and Allowance for Credit Losses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLossesTables</Role>
      <ShortName>Loans and Allowance for Credit Losses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLosses</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>99930403 - Disclosure - Time Deposits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureTimeDepositsTables</Role>
      <ShortName>Time Deposits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureTimeDeposits</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>99930503 - Disclosure - Borrowings (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureBorrowingsTables</Role>
      <ShortName>Borrowings (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureBorrowings</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>99930803 - Disclosure - Regulatory Matters (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureRegulatoryMattersTables</Role>
      <ShortName>Regulatory Matters (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureRegulatoryMatters</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>99930903 - Disclosure - Disclosures about Fair Value of Assets and Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureDisclosuresAboutFairValueOfAssetsAndLiabilitiesTables</Role>
      <ShortName>Disclosures about Fair Value of Assets and Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureDisclosuresAboutFairValueOfAssetsAndLiabilities</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>99940101 - Disclosure - Nature of Operations and Summary of Significant Accounting Policies - Nature of operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPoliciesNatureOfOperationsDetails</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting Policies - Nature of operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>99940102 - Disclosure - Nature of Operations and Summary of Significant Accounting Policies - Allowance for Credit Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPoliciesAllowanceForCreditLossesDetails</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting Policies - Allowance for Credit Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>99940103 - Disclosure - Nature of Operations and Summary of Significant Accounting Policies - Adoption of ASC 326 (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPoliciesAdoptionOfAsc326Details</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting Policies - Adoption of ASC 326 (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>99940201 - Disclosure - Investment Securities - Gross Unrealized Gains (Losses) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureInvestmentSecuritiesGrossUnrealizedGainsLossesDetails</Role>
      <ShortName>Investment Securities - Gross Unrealized Gains (Losses) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>99940202 - Disclosure - Investment Securities - Contractual Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureInvestmentSecuritiesContractualMaturityDetails</Role>
      <ShortName>Investment Securities - Contractual Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>99940203 - Disclosure - Investment Securities - Depreciation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureInvestmentSecuritiesDepreciationDetails</Role>
      <ShortName>Investment Securities - Depreciation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>99940204 - Disclosure - Investment Securities - Unrealized loss positions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureInvestmentSecuritiesUnrealizedLossPositionsDetails</Role>
      <ShortName>Investment Securities - Unrealized loss positions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>99940205 - Disclosure - Investment Securities - Additional information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails</Role>
      <ShortName>Investment Securities - Additional information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>99940301 - Disclosure - Loans and Allowance for Credit Losses - Categories of loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLossesCategoriesOfLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Categories of loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>99940302 - Disclosure - Loans and Allowance for Credit Losses - Allowance for credit losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLossesAllowanceForCreditLossesDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Allowance for credit losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>99940303 - Disclosure - Loans and Allowance for Credit Losses - Disaggregation based on the evaluation method (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLossesDisaggregationBasedOnEvaluationMethodDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Disaggregation based on the evaluation method (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>99940304 - Disclosure - Loans and Allowance for Credit Losses - Credit quality indicators (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLossesCreditQualityIndicatorsDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Credit quality indicators (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>99940305 - Disclosure - Loans and Allowance for Credit Losses - Aging analysis of the recorded investment in loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLossesAgingAnalysisOfRecordedInvestmentInLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Aging analysis of the recorded investment in loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>99940306 - Disclosure - Loans and Allowance for Credit Losses - Collateral dependent loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLossesCollateralDependentLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Collateral dependent loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>99940307 - Disclosure - Loans and Allowance for Credit Losses - Nonaccrual loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLossesNonaccrualLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Nonaccrual loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>99940308 - Disclosure - Loans and Allowance for Credit Losses - Additional information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureLoansAndAllowanceForCreditLossesAdditionalInformationDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Additional information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>99940401 - Disclosure - Time Deposits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureTimeDepositsDetails</Role>
      <ShortName>Time Deposits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureTimeDepositsTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>99940402 - Disclosure - Time Deposits - Maturities of Time Deposits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureTimeDepositsMaturitiesOfTimeDepositsDetails</Role>
      <ShortName>Time Deposits - Maturities of Time Deposits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>99940501 - Disclosure - Borrowings - FHLB advances (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureBorrowingsFhlbAdvancesDetails</Role>
      <ShortName>Borrowings - FHLB advances (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>99940502 - Disclosure - Borrowings - Line of Credit (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureBorrowingsLineOfCreditDetails</Role>
      <ShortName>Borrowings - Line of Credit (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>99940601 - Disclosure - Employee Stock Option Plan (ESOP) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureEmployeeStockOptionPlanEsopDetails</Role>
      <ShortName>Employee Stock Option Plan (ESOP) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureEmployeeStockOptionPlanEsop</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>99940701 - Disclosure - Earnings (Loss) Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureEarningsLossPerShareDetails</Role>
      <ShortName>Earnings (Loss) Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.monroefederal.com/role/DisclosureEarningsLossPerShare</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>99940801 - Disclosure - Regulatory Matters - Capital amounts and ratios (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureRegulatoryMattersCapitalAmountsAndRatiosDetails</Role>
      <ShortName>Regulatory Matters - Capital amounts and ratios (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>99940901 - Disclosure - Disclosures about Fair Value of Assets and Liabilities - Fair Value Hierarchy, Recurring (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureDisclosuresAboutFairValueOfAssetsAndLiabilitiesFairValueHierarchyRecurringDetails</Role>
      <ShortName>Disclosures about Fair Value of Assets and Liabilities - Fair Value Hierarchy, Recurring (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>99940902 - Disclosure - Disclosures about Fair Value of Assets and Liabilities - Fair Value Hierarchy, Nonrecurring (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureDisclosuresAboutFairValueOfAssetsAndLiabilitiesFairValueHierarchyNonrecurringDetails</Role>
      <ShortName>Disclosures about Fair Value of Assets and Liabilities - Fair Value Hierarchy, Nonrecurring (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="tmb-20241231x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>99940903 - Disclosure - Disclosures about Fair Value of Assets and Liabilities - Estimated fair values of financial instruments not carried at fair value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroefederal.com/role/DisclosureDisclosuresAboutFairValueOfAssetsAndLiabilitiesEstimatedFairValuesOfFinancialInstrumentsNotCarriedAtFairValueDetails</Role>
      <ShortName>Disclosures about Fair Value of Assets and Liabilities - Estimated fair values of financial instruments not carried at fair value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>tmb-20241231.xsd</File>
    <File>tmb-20241231_cal.xml</File>
    <File>tmb-20241231_def.xml</File>
    <File>tmb-20241231_lab.xml</File>
    <File>tmb-20241231_pre.xml</File>
    <File doctype="10-Q" isDefinitelyFs="true" isUsgaap="true" original="tmb-20241231x10q.htm">tmb-20241231x10q.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>tmb-20241231x10q003.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="1032">http://fasb.org/us-gaap/2024</BaseTaxonomy>
    <BaseTaxonomy items="27">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>
