<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.24.1.1.u2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>330</ContextCount>
  <ElementCount>446</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>97</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>100000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>100010 - Statement - Consolidated Statements Of Financial Condition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/StatementConsolidatedStatementsOfFinancialCondition</Role>
      <ShortName>Consolidated Statements Of Financial Condition</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>100050 - Statement - Consolidated Statements Of Financial Condition (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/StatementConsolidatedStatementsOfFinancialConditionParenthetical</Role>
      <ShortName>Consolidated Statements Of Financial Condition (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>100060 - Statement - Consolidated Statements of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/StatementConsolidatedStatementsOfIncome</Role>
      <ShortName>Consolidated Statements of Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>100070 - Statement - Consolidated Statements Of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statements Of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>100080 - Statement - Consolidated Statements of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/StatementConsolidatedStatementsOfStockholdersEquity</Role>
      <ShortName>Consolidated Statements of Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>100090 - Statement - Consolidated Statements of Stockholders' Equity (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/StatementConsolidatedStatementsOfStockholdersEquityParenthetical</Role>
      <ShortName>Consolidated Statements of Stockholders' Equity (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>100100 - Statement - Condensed Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/StatementCondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.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>9</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.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>10</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995455 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995465 - Disclosure - Investment Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureInvestmentSecurities</Role>
      <ShortName>Investment Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995475 - Disclosure - Loans and Allowance for Credit Losses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLosses1</Role>
      <ShortName>Loans and Allowance for Credit Losses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995485 - Disclosure - Premises And Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePremisesAndEquipment</Role>
      <ShortName>Premises And Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995495 - Disclosure - Deposits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureDeposits1</Role>
      <ShortName>Deposits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995505 - Disclosure - Borrowings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureBorrowings</Role>
      <ShortName>Borrowings</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995515 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995525 - Disclosure - Regulatory Capital Requirements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureRegulatoryCapitalRequirements</Role>
      <ShortName>Regulatory Capital Requirements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995535 - Disclosure - Mortgage Servicing</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureMortgageServicing</Role>
      <ShortName>Mortgage Servicing</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995545 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995555 - Disclosure - Fair Value Of Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureFairValueOfFinancialInstruments</Role>
      <ShortName>Fair Value Of Financial Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995565 - Disclosure - Accumulated Other Comprehensive Loss</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLoss</Role>
      <ShortName>Accumulated Other Comprehensive Loss</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995575 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLeases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995585 - Disclosure - Pension Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePensionPlan</Role>
      <ShortName>Pension Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995595 - Disclosure - Low Income Housing Tax Credit</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLowIncomeHousingTaxCredit1</Role>
      <ShortName>Low Income Housing Tax Credit</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995605 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995615 - Disclosure - ESOP</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEsop</Role>
      <ShortName>ESOP</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995625 - Disclosure - Condensed Parent only Financial Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureCondensedParentOnlyFinancialInformation</Role>
      <ShortName>Condensed Parent only Financial Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995635 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureSubsequentEvents1</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995645 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995655 - Disclosure - Investment Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureInvestmentSecuritiesTables</Role>
      <ShortName>Investment Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureInvestmentSecurities</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995665 - Disclosure - Loans and Allowance for Credit Losses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesTables</Role>
      <ShortName>Loans and Allowance for Credit Losses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLosses1</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995675 - Disclosure - Premises And Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePremisesAndEquipmentTables</Role>
      <ShortName>Premises And Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePremisesAndEquipment</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995685 - Disclosure - Deposits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureDepositsTables</Role>
      <ShortName>Deposits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureDeposits1</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995695 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureIncomeTaxes</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995705 - Disclosure - Regulatory Capital Requirements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureRegulatoryCapitalRequirementsTables</Role>
      <ShortName>Regulatory Capital Requirements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureRegulatoryCapitalRequirements</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995715 - Disclosure - Mortgage Servicing (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureMortgageServicingTables</Role>
      <ShortName>Mortgage Servicing (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureMortgageServicing</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995725 - Disclosure - Fair Value Of Financial Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureFairValueOfFinancialInstrumentsTables</Role>
      <ShortName>Fair Value Of Financial Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureFairValueOfFinancialInstruments</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995735 - Disclosure - Accumulated Other Comprehensive Loss (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLossTables</Role>
      <ShortName>Accumulated Other Comprehensive Loss (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLoss</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995745 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLeases</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995755 - Disclosure - Pension Plan (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePensionPlanTables</Role>
      <ShortName>Pension Plan (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePensionPlan</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995765 - Disclosure - Low Income Housing Tax Credit (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLowIncomeHousingTaxCreditTables</Role>
      <ShortName>Low Income Housing Tax Credit (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLowIncomeHousingTaxCredit1</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995775 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEarningsPerShare</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995785 - Disclosure - ESOP (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEsopTables</Role>
      <ShortName>ESOP (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEsop</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995795 - Disclosure - Condensed Parent only Financial Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureCondensedParentOnlyFinancialInformationTables</Role>
      <ShortName>Condensed Parent only Financial Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureCondensedParentOnlyFinancialInformation</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995805 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995815 - Disclosure - Investment Securities - Summary of Investment Securities Available for Sale (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureInvestmentSecuritiesSummaryOfInvestmentSecuritiesAvailableForSaleDetails</Role>
      <ShortName>Investment Securities - Summary of Investment Securities Available for Sale (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995825 - Disclosure - Investment Securities - Summary of Investment Securities Held to Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureInvestmentSecuritiesSummaryOfInvestmentSecuritiesHeldToMaturityDetails</Role>
      <ShortName>Investment Securities - Summary of Investment Securities Held to Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995835 - Disclosure - Investment Securities - Summary of Debt Securities Available for Sale and Unrealized Loss Position (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureInvestmentSecuritiesSummaryOfDebtSecuritiesAvailableForSaleAndUnrealizedLossPositionDetails</Role>
      <ShortName>Investment Securities - Summary of Debt Securities Available for Sale and Unrealized Loss Position (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995845 - Disclosure - Investment Securities - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails</Role>
      <ShortName>Investment Securities - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995855 - Disclosure - Investment Securities - Schedule of Amortized Cost and Fair Value of Available for sale Investment Securities by Contractual Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureInvestmentSecuritiesScheduleOfAmortizedCostAndFairValueOfAvailableForSaleInvestmentSecuritiesByContractualMaturityDetails</Role>
      <ShortName>Investment Securities - Schedule of Amortized Cost and Fair Value of Available for sale Investment Securities by Contractual Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995865 - Disclosure - Loans and Allowance for Credit Losses - Summary of Loans Receivable and Related Reclassifications (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesSummaryOfLoansReceivableAndRelatedReclassificationsDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Summary of Loans Receivable and Related Reclassifications (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995875 - Disclosure - Loans and Allowance for Credit Losses - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesAdditionalInformationDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995885 - Disclosure - Loans and Allowance for Credit Losses - Schedule of Activity in Allowance for Credit Losses and Allowance for Loan Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesScheduleOfActivityInAllowanceForCreditLossesAndAllowanceForLoanLossesDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Schedule of Activity in Allowance for Credit Losses and Allowance for Loan Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>995895 - Disclosure - Loans and Allowance for Credit Losses - Schedule of Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segments and based on Impairment Method (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesScheduleOfAllowanceForLoanLossesAndRecordedInvestmentInLoansByPortfolioSegmentsAndBasedOnImp</Role>
      <ShortName>Loans and Allowance for Credit Losses - Schedule of Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segments and based on Impairment Method (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>995905 - Disclosure - Loans and Allowance for Credit Losses - Summary of Impaired Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesSummaryOfImpairedLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Summary of Impaired Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>995915 - Disclosure - Loans and Allowance for Credit Losses - Summary of Loans Individually Evaluated (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesSummaryOfLoansIndividuallyEvaluatedDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Summary of Loans Individually Evaluated (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>995925 - Disclosure - Loans and Allowance for Credit Losses - Summary Of Risk Category of Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesSummaryOfRiskCategoryOfLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Summary Of Risk Category of Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>995935 - Disclosure - Loans and Allowance for Credit Losses - Schedule of Loans on Nonaccrual Status (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesScheduleOfLoansOnNonaccrualStatusDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Schedule of Loans on Nonaccrual Status (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>995945 - Disclosure - Loans and Allowance for Credit Losses - Summary of Recorded Investment in Nonaccrual and Loans Past Due (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesSummaryOfRecordedInvestmentInNonaccrualAndLoansPastDueDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Summary of Recorded Investment in Nonaccrual and Loans Past Due (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>995955 - Disclosure - Loans and Allowance for Credit Losses - Schedule of Aging Analysis of Contractually Past Due Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesScheduleOfAgingAnalysisOfContractuallyPastDueLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Schedule of Aging Analysis of Contractually Past Due Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>995965 - Disclosure - Premises and Equipment - Schedule of Premises and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePremisesAndEquipmentScheduleOfPremisesAndEquipmentDetails</Role>
      <ShortName>Premises and Equipment - Schedule of Premises and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>995975 - Disclosure - Premises and Equipment - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePremisesAndEquipmentAdditionalInformationDetails</Role>
      <ShortName>Premises and Equipment - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>995985 - Disclosure - Deposits - Summary of Certificates of Deposit (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureDepositsSummaryOfCertificatesOfDepositDetails</Role>
      <ShortName>Deposits - Summary of Certificates of Deposit (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>995995 - Disclosure - Deposits - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureDepositsAdditionalInformationDetails</Role>
      <ShortName>Deposits - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>996005 - Disclosure - Borrowings - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureBorrowingsAdditionalInformationDetails</Role>
      <ShortName>Borrowings - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>996015 - Disclosure - Income Taxes - Summary of Components of Income Tax Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureIncomeTaxesSummaryOfComponentsOfIncomeTaxExpenseDetails</Role>
      <ShortName>Income Taxes - Summary of Components of Income Tax Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>996025 - Disclosure - Income Taxes - Summary of Provision for Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureIncomeTaxesSummaryOfProvisionForIncomeTaxesDetails</Role>
      <ShortName>Income Taxes - Summary of Provision for Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>996035 - Disclosure - Income Taxes - Summary of Provision for Income Taxes (Parenthetical) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureIncomeTaxesSummaryOfProvisionForIncomeTaxesParentheticalDetails</Role>
      <ShortName>Income Taxes - Summary of Provision for Income Taxes (Parenthetical) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>996045 - Disclosure - Income Taxes - Summary of Deferred Tax Assets and Deferred Tax Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureIncomeTaxesSummaryOfDeferredTaxAssetsAndDeferredTaxLiabilitiesDetails</Role>
      <ShortName>Income Taxes - Summary of Deferred Tax Assets and Deferred Tax Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>996055 - Disclosure - Income Taxes - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails</Role>
      <ShortName>Income Taxes - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>996065 - Disclosure - Regulatory Capital Requirements - Schedule of Actual Capital Amounts and Ratios (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureRegulatoryCapitalRequirementsScheduleOfActualCapitalAmountsAndRatiosDetails</Role>
      <ShortName>Regulatory Capital Requirements - Schedule of Actual Capital Amounts and Ratios (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>996075 - Disclosure - Mortgage Servicing - Summary of Activity in Mortgage Servicing Rights Using Amortized Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureMortgageServicingSummaryOfActivityInMortgageServicingRightsUsingAmortizedCostDetails</Role>
      <ShortName>Mortgage Servicing - Summary of Activity in Mortgage Servicing Rights Using Amortized Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>996085 - Disclosure - Mortgage Servicing - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureMortgageServicingAdditionalInformationDetails</Role>
      <ShortName>Mortgage Servicing - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>996095 - Disclosure - Commitments and Contingencies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>996105 - Disclosure - Fair Value Of Financial Instruments - Summary Of Carrying Amounts And Estimated Fair Values By Fair Value Hierarchy Of Certain Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureFairValueOfFinancialInstrumentsSummaryOfCarryingAmountsAndEstimatedFairValuesByFairValueHierarchyOfCertainFinancialInstruments</Role>
      <ShortName>Fair Value Of Financial Instruments - Summary Of Carrying Amounts And Estimated Fair Values By Fair Value Hierarchy Of Certain Financial Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>996115 - Disclosure - Fair Value Of Financial Instruments - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureFairValueOfFinancialInstrumentsAdditionalInformationDetails</Role>
      <ShortName>Fair Value Of Financial Instruments - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>996125 - Disclosure - Fair Value Of Financial Instruments - Summary of Financial Assets Measured at Fair Value on a Recurring Basis are Available-for-Sale Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureFairValueOfFinancialInstrumentsSummaryOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisAreAvailableforsaleSecuritiesDetails</Role>
      <ShortName>Fair Value Of Financial Instruments - Summary of Financial Assets Measured at Fair Value on a Recurring Basis are Available-for-Sale Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>996135 - Disclosure - Fair Value Of Financial Instruments - Summary of Fair Value Measurement of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureFairValueOfFinancialInstrumentsSummaryOfFairValueMeasurementOfAssetsAndLiabilitiesMeasuredAtFairValueOnANonrecurringBasisDeta</Role>
      <ShortName>Fair Value Of Financial Instruments - Summary of Fair Value Measurement of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>996145 - Disclosure - Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLossScheduleOfAccumulatedOtherComprehensiveLossDetails</Role>
      <ShortName>Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>996155 - Disclosure - Accumulated Other Comprehensive Loss - Schedule of Reclassifications out of Accumulated Other Comprehensive Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveLossScheduleOfReclassificationsOutOfAccumulatedOtherComprehensiveLossDetails</Role>
      <ShortName>Accumulated Other Comprehensive Loss - Schedule of Reclassifications out of Accumulated Other Comprehensive Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>996165 - Disclosure - Leases - Schedule of the Future Undiscounted Lease Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLeasesScheduleOfTheFutureUndiscountedLeasePaymentsDetails</Role>
      <ShortName>Leases - Schedule of the Future Undiscounted Lease Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>996175 - Disclosure - Leases - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLeasesAdditionalInformationDetails</Role>
      <ShortName>Leases - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>996185 - Disclosure - Pension Plan - Schedule of Fair Value of Plan Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePensionPlanScheduleOfFairValueOfPlanAssetsDetails</Role>
      <ShortName>Pension Plan - Schedule of Fair Value of Plan Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>996195 - Disclosure - Pension Plan - Schedule of Reconciliation of Changes in Benefit Obligations and Plan Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePensionPlanScheduleOfReconciliationOfChangesInBenefitObligationsAndPlanAssetsDetails</Role>
      <ShortName>Pension Plan - Schedule of Reconciliation of Changes in Benefit Obligations and Plan Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>996205 - Disclosure - Pension Plan - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePensionPlanAdditionalInformationDetails</Role>
      <ShortName>Pension Plan - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>996215 - Disclosure - Pension Plan - Schedule of Net Periodic Benefit Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePensionPlanScheduleOfNetPeriodicBenefitCostDetails</Role>
      <ShortName>Pension Plan - Schedule of Net Periodic Benefit Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>996225 - Disclosure - Pension Plan - Schedule of Defined Benefit Plan, Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePensionPlanScheduleOfDefinedBenefitPlanAssumptionsDetails</Role>
      <ShortName>Pension Plan - Schedule of Defined Benefit Plan, Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>996235 - Disclosure - Pension Plan - Schedule of Expected Benefit Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosurePensionPlanScheduleOfExpectedBenefitPaymentsDetails</Role>
      <ShortName>Pension Plan - Schedule of Expected Benefit Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>996245 - Disclosure - Low Income housing tax credit - Summary of Affordable Housing Tax Credit Investment and Related Unfunded Commitment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLowIncomeHousingTaxCreditSummaryOfAffordableHousingTaxCreditInvestmentAndRelatedUnfundedCommitmentDetails</Role>
      <ShortName>Low Income housing tax credit - Summary of Affordable Housing Tax Credit Investment and Related Unfunded Commitment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>996255 - Disclosure - Low Income housing tax credit - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureLowIncomeHousingTaxCreditAdditionalInformationDetails</Role>
      <ShortName>Low Income housing tax credit - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>996265 - Disclosure - Earnings Per Share - Summary of Earnings Per Share Basic and Diluted (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEarningsPerShareSummaryOfEarningsPerShareBasicAndDilutedDetails</Role>
      <ShortName>Earnings Per Share - Summary of Earnings Per Share Basic and Diluted (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>996275 - Disclosure - Earnings Per Share - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEarningsPerShareAdditionalInformationDetails</Role>
      <ShortName>Earnings Per Share - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>996285 - Disclosure - ESOP - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEsopAdditionalInformationDetails</Role>
      <ShortName>ESOP - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>996295 - Disclosure - ESOP - Schedule of Shares Held by the ESOP (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureEsopScheduleOfSharesHeldByTheEsopDetails</Role>
      <ShortName>ESOP - Schedule of Shares Held by the ESOP (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>996305 - Disclosure - Condensed Parent only Financial Information - Schedule of Condensed Balance Sheets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureCondensedParentOnlyFinancialInformationScheduleOfCondensedBalanceSheetsDetails</Role>
      <ShortName>Condensed Parent only Financial Information - Schedule of Condensed Balance Sheets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>996315 - Disclosure - Condensed Parent only Financial Information - Schedule of Condensed Statements of Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureCondensedParentOnlyFinancialInformationScheduleOfCondensedStatementsOfOperationsDetails</Role>
      <ShortName>Condensed Parent only Financial Information - Schedule of Condensed Statements of Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="cpbi-20240331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>996325 - Disclosure - Condensed Parent only Financial Information - Schedule of Condensed Statements of Cash Flows (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.homefederalne.bank/20240331/taxonomy/role/DisclosureCondensedParentOnlyFinancialInformationScheduleOfCondensedStatementsOfCashFlowsDetails</Role>
      <ShortName>Condensed Parent only Financial Information - Schedule of Condensed Statements of Cash Flows (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Warning">[ix-0514-Hidden-Fact-Eligible-For-Transform] WARN: 2 fact(s) appearing in ix:hidden were eligible for transformation: cpbi:ConsumerPortfolioAdjustedAmortizedPeriod, cpbi:ConsumerPortfolioAmortizedTerms -  cpbi-20240331.htm 8</Log>
  </Logs>
  <InputFiles>
    <File doctype="10-K" isDefinitelyFs="true" isUsgaap="true" original="cpbi-20240331.htm">cpbi-20240331.htm</File>
    <File>cpbi-20240331.xsd</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="3">http://fasb.org/srt/2023</BaseTaxonomy>
    <BaseTaxonomy items="1178">http://fasb.org/us-gaap/2023</BaseTaxonomy>
    <BaseTaxonomy items="39">http://xbrl.sec.gov/dei/2023</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/ecd/2023</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
