<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>487</ContextCount>
  <ElementCount>232</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>77</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>001 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ConsolidatedBalanceSheet</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>002 - Statement - Condensed Consolidated Balance Sheets (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ConsolidatedBalanceSheet_Parentheticals</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>003 - Statement - Condensed Consolidated Statements of Operations (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ConsolidatedIncomeStatement</Role>
      <ShortName>Condensed Consolidated Statements of Operations (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>004 - Statement - Condensed Consolidated Statements of Comprehensive Income (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ConsolidatedComprehensiveIncome</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>005 - Statement - Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ConsolidatedComprehensiveIncome_Parentheticals</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>006 - Statement - Consolidated Statements of Changes in Shareholders??? Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ShareholdersEquityType2or3</Role>
      <ShortName>Consolidated Statements of Changes in Shareholders??? Equity (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>007 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ConsolidatedCashFlow</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>008 - Disclosure - Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/BasisofPresentation</Role>
      <ShortName>Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>009 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/EarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>010 - Disclosure - Debt Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/DebtSecurities</Role>
      <ShortName>Debt Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>011 - Disclosure - Loans Receivable</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/LoansReceivable</Role>
      <ShortName>Loans Receivable</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>012 - Disclosure - Disclosures About Fair Value of Assets and Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/DisclosuresAboutFairValueofAssetsandLiabilities</Role>
      <ShortName>Disclosures About Fair Value of Assets and Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>013 - Disclosure - Other Comprehensive Income (Loss)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/OtherComprehensiveIncomeLoss</Role>
      <ShortName>Other Comprehensive Income (Loss)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>014 - Disclosure - Regulatory Matters</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/RegulatoryMatters</Role>
      <ShortName>Regulatory Matters</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.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>16</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.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>17</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>996000 - Disclosure - Accounting Policies, by Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/AccountingPoliciesByPolicy</Role>
      <ShortName>Accounting Policies, by Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>996001 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/EarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/EarningsPerShare</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>996002 - Disclosure - Debt Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/DebtSecuritiesTables</Role>
      <ShortName>Debt Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/DebtSecurities</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>996003 - Disclosure - Loans Receivable (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/LoansReceivableTables</Role>
      <ShortName>Loans Receivable (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/LoansReceivable</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>996004 - Disclosure - Disclosures About Fair Value of Assets and Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/DisclosuresAboutFairValueofAssetsandLiabilitiesTables</Role>
      <ShortName>Disclosures About Fair Value of Assets and Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/DisclosuresAboutFairValueofAssetsandLiabilities</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>996005 - Disclosure - Other Comprehensive Income (Loss) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/OtherComprehensiveIncomeLossTables</Role>
      <ShortName>Other Comprehensive Income (Loss) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/OtherComprehensiveIncomeLoss</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>996006 - Disclosure - Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/EarningsPerShareDetails</Role>
      <ShortName>Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/EarningsPerShareTables</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>996007 - Disclosure - Earnings Per Share - Schedule of Basic and Diluted Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofBasicandDilutedEarningsPerShareTable</Role>
      <ShortName>Earnings Per Share - Schedule of Basic and Diluted Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>996008 - Disclosure - Debt Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/DebtSecuritiesDetails</Role>
      <ShortName>Debt Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/DebtSecuritiesTables</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>996009 - Disclosure - Debt Securities - Schedule of Amortized Cost and Fair Value of Securities Available-for-Sale and Securities Held-to-Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofAmortizedCostandFairValueofSecuritiesAvailableforSaleandSecuritiesHeldtoMaturityTable</Role>
      <ShortName>Debt Securities - Schedule of Amortized Cost and Fair Value of Securities Available-for-Sale and Securities Held-to-Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>996010 - Disclosure - Loans Receivable (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/LoansReceivableDetails</Role>
      <ShortName>Loans Receivable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/LoansReceivableTables</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>996011 - Disclosure - Loans Receivable - Schedule of Loan Portfolio (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofLoanPortfolioTable</Role>
      <ShortName>Loans Receivable - Schedule of Loan Portfolio (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>996012 - Disclosure - Loans Receivable - Schedule of ACL by Portfolio Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofACLbyPortfolioSegmentTable</Role>
      <ShortName>Loans Receivable - Schedule of ACL by Portfolio Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>996013 - Disclosure - Loans Receivable - Schedule of Amortized Cost Basis of Collateral-Dependent Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofAmortizedCostBasisofCollateralDependentLoansTable</Role>
      <ShortName>Loans Receivable - Schedule of Amortized Cost Basis of Collateral-Dependent Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>996014 - Disclosure - Loans Receivable - Schedule of Table Presents the Recorded Investment in Nonaccrual and Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofTablePresentstheRecordedInvestmentinNonaccrualandLoansTable</Role>
      <ShortName>Loans Receivable - Schedule of Table Presents the Recorded Investment in Nonaccrual and Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>996015 - Disclosure - Loans Receivable - Schedule of Principal Balance Outstanding in Past Due Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofPrincipalBalanceOutstandinginPastDueLoansTable</Role>
      <ShortName>Loans Receivable - Schedule of Principal Balance Outstanding in Past Due Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>996016 - Disclosure - Loans Receivable - Schedule of Analysis Performed, the Risk Category of Loans by Class of Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofAnalysisPerformedtheRiskCategoryofLoansbyClassofLoansTable</Role>
      <ShortName>Loans Receivable - Schedule of Analysis Performed, the Risk Category of Loans by Class of Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>996017 - Disclosure - Loans Receivable - Schedule of Purchased Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofPurchasedLoansTable</Role>
      <ShortName>Loans Receivable - Schedule of Purchased Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>996018 - Disclosure - Loans Receivable - Schedule of Accretable Yield, or Income Expected to be Collected (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofAccretableYieldorIncomeExpectedtobeCollectedTable</Role>
      <ShortName>Loans Receivable - Schedule of Accretable Yield, or Income Expected to be Collected (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>996019 - Disclosure - Disclosures About Fair Value of Assets and Liabilities - Schedule of Financial Assets Measured at Fair Value on a Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofFinancialAssetsMeasuredatFairValueonaRecurringBasisTable</Role>
      <ShortName>Disclosures About Fair Value of Assets and Liabilities - Schedule of Financial Assets Measured at Fair Value on a Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>996020 - Disclosure - Disclosures About Fair Value of Assets and Liabilities - Schedule of Carrying Value and Fair Value of the Company???s Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofCarryingValueandFairValueoftheCompanysFinancialInstrumentsTable</Role>
      <ShortName>Disclosures About Fair Value of Assets and Liabilities - Schedule of Carrying Value and Fair Value of the Company???s Financial Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>996021 - Disclosure - Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income Balances, Net of Tax (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofAccumulatedOtherComprehensiveIncomeBalancesNetofTaxTable</Role>
      <ShortName>Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income Balances, Net of Tax (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/OtherComprehensiveIncomeLossTables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="ea0290159-10q_kentucky.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>996022 - Disclosure - Other Comprehensive Income (Loss) - Schedule of Other Comprehensive Income (Loss) Components and Related Tax Effects (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.kentuckyfirstfederalbancorp.com/role/ScheduleofOtherComprehensiveIncomeLossComponentsandRelatedTaxEffectsTable</Role>
      <ShortName>Other Comprehensive Income (Loss) - Schedule of Other Comprehensive Income (Loss) Components and Related Tax Effects (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.kentuckyfirstfederalbancorp.com/role/OtherComprehensiveIncomeLossTables</ParentRole>
      <Position>40</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-Q" isDefinitelyFs="true" isUsgaap="true" original="ea0290159-10q_kentucky.htm">ea0290159-10q_kentucky.htm</File>
    <File>kffb-20260331.xsd</File>
    <File>kffb-20260331_cal.xml</File>
    <File>kffb-20260331_def.xml</File>
    <File>kffb-20260331_lab.xml</File>
    <File>kffb-20260331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="1">http://fasb.org/srt/2026</BaseTaxonomy>
    <BaseTaxonomy items="1800">http://fasb.org/us-gaap/2026</BaseTaxonomy>
    <BaseTaxonomy items="29">http://xbrl.sec.gov/dei/2026</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/ecd/2026</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
