<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.4</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>421</ContextCount>
  <ElementCount>596</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>111</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>14</UnitCount>
  <MyReports>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>75000 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>75010 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>75020 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>75030 - Statement - Consolidated Statements of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_StatementConsolidatedStatementsOfIncome</Role>
      <ShortName>Consolidated Statements of Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>75040 - Statement - Consolidated Statements of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_StatementConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statements of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>75050 - Statement - Consolidated Statements of Changes in Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_StatementConsolidatedStatementsOfChangesInShareholdersEquity</Role>
      <ShortName>Consolidated Statements of Changes in Shareholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>75060 - Statement - Consolidated Statements of Changes In Shareholders' Equity (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_StatementConsolidatedStatementsOfChangesInShareholdersEquityParenthetical</Role>
      <ShortName>Consolidated Statements of Changes In Shareholders' Equity (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>75070 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="pb-20251231.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="pb-20251231.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="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995447 - Disclosure - Insider Trading Policies and Procedures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc</Role>
      <ShortName>Insider Trading Policies and Procedures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995457 - Disclosure - Cybersecurity Risk Management, Strategy and Governance</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureCybersecurityRiskManagementStrategyAndGovernance</Role>
      <ShortName>Cybersecurity Risk Management, Strategy and Governance</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995467 - Disclosure - Nature of Operations and Summary of Significant Accounting and Reporting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingAndReportingPolicies</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting and Reporting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995477 - Disclosure - Acquisitions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureAcquisitions</Role>
      <ShortName>Acquisitions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995487 - Disclosure - Goodwill and Core Deposit Intangibles</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureGoodwillAndCoreDepositIntangibles</Role>
      <ShortName>Goodwill and Core Deposit Intangibles</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995497 - Disclosure - Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureSecurities</Role>
      <ShortName>Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995507 - Disclosure - Loans and Allowance for Credit Losses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLosses</Role>
      <ShortName>Loans and Allowance for Credit Losses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995517 - Disclosure - Fair Value</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureFairValue</Role>
      <ShortName>Fair Value</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995527 - Disclosure - Premises and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosurePremisesAndEquipment</Role>
      <ShortName>Premises and Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995537 - Disclosure - Deposits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDeposits</Role>
      <ShortName>Deposits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995547 - Disclosure - Other Borrowings and Securities Sold under Repurchase Agreements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreements</Role>
      <ShortName>Other Borrowings and Securities Sold under Repurchase Agreements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995557 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995567 - Disclosure - Stock Incentive Programs</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureStockIncentivePrograms</Role>
      <ShortName>Stock Incentive Programs</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995577 - Disclosure - Other Noninterest Income and Expense</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOtherNoninterestIncomeAndExpense</Role>
      <ShortName>Other Noninterest Income and Expense</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995587 - Disclosure - Profit Sharing Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureProfitSharingPlan</Role>
      <ShortName>Profit Sharing Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995597 - Disclosure - Off-Balance Sheet Arrangements, Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOffBalanceSheetArrangementsCommitmentsAndContingencies</Role>
      <ShortName>Off-Balance Sheet Arrangements, Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995607 - Disclosure - Other Comprehensive (Loss) Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherComprehensiveLossIncome1</Role>
      <ShortName>Other Comprehensive (Loss) Income</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995617 - Disclosure - Derivative Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDerivativeFinancialInstruments</Role>
      <ShortName>Derivative Financial Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995627 - Disclosure - Regulatory Matters</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureRegulatoryMatters</Role>
      <ShortName>Regulatory Matters</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995637 - Disclosure - Parent Company Only Financial Statements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureParentCompanyOnlyFinancialStatements</Role>
      <ShortName>Parent Company Only Financial Statements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995647 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995657 - Disclosure - Nature of Operations and Summary of Significant Accounting and Reporting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingAndReportingPoliciesPolicies</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting and Reporting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingAndReportingPolicies</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995667 - Disclosure - Nature of Operations and Summary of Significant Accounting and Reporting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingAndReportingPoliciesTables</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting and Reporting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingAndReportingPolicies</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995677 - Disclosure - Acquisitions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureAcquisitionsTables</Role>
      <ShortName>Acquisitions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureAcquisitions</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995687 - Disclosure - Goodwill and Core Deposit Intangibles (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureGoodwillAndCoreDepositIntangiblesTables</Role>
      <ShortName>Goodwill and Core Deposit Intangibles (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureGoodwillAndCoreDepositIntangibles</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995697 - Disclosure - Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureSecuritiesTables</Role>
      <ShortName>Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureSecurities</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995707 - Disclosure - Loans and Allowance for Credit Losses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesTables</Role>
      <ShortName>Loans and Allowance for Credit Losses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLosses</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995717 - Disclosure - Fair Value (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureFairValueTables</Role>
      <ShortName>Fair Value (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureFairValue</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995727 - Disclosure - Premises and Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosurePremisesAndEquipmentTables</Role>
      <ShortName>Premises and Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosurePremisesAndEquipment</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995737 - Disclosure - Deposits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDepositsTables</Role>
      <ShortName>Deposits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDeposits</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995747 - Disclosure - Other Borrowings and Securities Sold Under Repurchase Agreements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreementsTables</Role>
      <ShortName>Other Borrowings and Securities Sold Under Repurchase Agreements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995757 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxes</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995767 - Disclosure - Stock Incentive Programs (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureStockIncentiveProgramsTables</Role>
      <ShortName>Stock Incentive Programs (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureStockIncentivePrograms</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995777 - Disclosure - Other Noninterest Income and Expense (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOtherNoninterestIncomeAndExpenseTables</Role>
      <ShortName>Other Noninterest Income and Expense (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOtherNoninterestIncomeAndExpense</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995787 - Disclosure - Off-Balance Sheet Arrangements, Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOffBalanceSheetArrangementsCommitmentsAndContingenciesTables</Role>
      <ShortName>Off-Balance Sheet Arrangements, Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOffBalanceSheetArrangementsCommitmentsAndContingencies</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995797 - Disclosure - Other Comprehensive (Loss) Income (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherComprehensiveLossIncomeTables</Role>
      <ShortName>Other Comprehensive (Loss) Income (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherComprehensiveLossIncome1</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995807 - Disclosure - Derivative Financial Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDerivativeFinancialInstrumentsTables</Role>
      <ShortName>Derivative Financial Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDerivativeFinancialInstruments</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995817 - Disclosure - Regulatory Matters (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureRegulatoryMattersTables</Role>
      <ShortName>Regulatory Matters (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureRegulatoryMatters</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995827 - Disclosure - Parent Company Only Financial Statements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureParentCompanyOnlyFinancialStatementsTables</Role>
      <ShortName>Parent Company Only Financial Statements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureParentCompanyOnlyFinancialStatements</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995837 - Disclosure - Nature of Operations and Summary of Significant Accounting and Reporting Policies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingAndReportingPoliciesAdditionalInformationDetails</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting and Reporting Policies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995847 - Disclosure - Nature of Operations and Summary of Significant Accounting and Reporting Policies - Computation of Basic and Diluted Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingAndReportingPoliciesComputationOfBasicAndDilutedEarningsPerShareDetails</Role>
      <ShortName>Nature of Operations and Summary of Significant Accounting and Reporting Policies - Computation of Basic and Diluted Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995857 - Disclosure - Acquisitions - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureAcquisitionsAdditionalInformationDetails</Role>
      <ShortName>Acquisitions - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995867 - Disclosure - Acquisitions - Recorded Investment and Outstanding Balance for Purchased Credit Deteriorated Loans and Non Purchased Credit Deteriorated Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureAcquisitionsRecordedInvestmentAndOutstandingBalanceForPurchasedCreditDeterioratedLoansAndNonPurchasedCreditDeterioratedLoansDetails</Role>
      <ShortName>Acquisitions - Recorded Investment and Outstanding Balance for Purchased Credit Deteriorated Loans and Non Purchased Credit Deteriorated Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995877 - Disclosure - Acquisitions - Summary of Changes in Accretable Yields of Acquired Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureAcquisitionsSummaryOfChangesInAccretableYieldsOfAcquiredLoansDetails</Role>
      <ShortName>Acquisitions - Summary of Changes in Accretable Yields of Acquired Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>995887 - Disclosure - Acquisitions (Acquired Loans) - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureAcquisitionsAcquiredLoansAdditionalInformationDetails</Role>
      <ShortName>Acquisitions (Acquired Loans) - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureAcquisitionsTables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>995897 - Disclosure - Goodwill and Core Deposit Intangibles - Goodwill and Core Deposit Intangibles (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureGoodwillAndCoreDepositIntangiblesGoodwillAndCoreDepositIntangiblesDetails</Role>
      <ShortName>Goodwill and Core Deposit Intangibles - Goodwill and Core Deposit Intangibles (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>995907 - Disclosure - Goodwill and Core Deposit Intangibles - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureGoodwillAndCoreDepositIntangiblesAdditionalInformationDetails</Role>
      <ShortName>Goodwill and Core Deposit Intangibles - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>995917 - Disclosure - Goodwill and Core Deposit Intangibles - Estimated Aggregate Future Amortization Expense for Core Deposit Intangibles (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureGoodwillAndCoreDepositIntangiblesEstimatedAggregateFutureAmortizationExpenseForCoreDepositIntangiblesDetails</Role>
      <ShortName>Goodwill and Core Deposit Intangibles - Estimated Aggregate Future Amortization Expense for Core Deposit Intangibles (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>995927 - Disclosure - Securities - Schedule of Amortized Cost and Fair Value of Investment Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureSecuritiesScheduleOfAmortizedCostAndFairValueOfInvestmentSecuritiesDetails</Role>
      <ShortName>Securities - Schedule of Amortized Cost and Fair Value of Investment Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>995937 - Disclosure - Securities - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureSecuritiesAdditionalInformationDetails</Role>
      <ShortName>Securities - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>995947 - Disclosure - Securities - Securities in Continuous Loss Position (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureSecuritiesSecuritiesInContinuousLossPositionDetails</Role>
      <ShortName>Securities - Securities in Continuous Loss Position (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>995957 - Disclosure - Securities - Investment Securities by Contractual Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureSecuritiesInvestmentSecuritiesByContractualMaturityDetails</Role>
      <ShortName>Securities - Investment Securities by Contractual Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>995967 - Disclosure - Loans and Allowance for Credit Losses - Types of Loans in Loan Portfolio (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesTypesOfLoansInLoanPortfolioDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Types of Loans in Loan Portfolio (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>995977 - Disclosure - Loans and Allowance for Credit Losses - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesAdditionalInformationDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>995987 - Disclosure - Loans and Allowance for Credit Losses - Schedule of Contractual Maturities of Loans Classified by Major Type (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesScheduleOfContractualMaturitiesOfLoansClassifiedByMajorTypeDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Schedule of Contractual Maturities of Loans Classified by Major Type (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>995997 - Disclosure - Loans and Allowance for Credit Losses - Related Party Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesRelatedPartyLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Related Party Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>996007 - Disclosure - Loans and Allowance for Credit Losses - Aging Analysis of Past Due Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesAgingAnalysisOfPastDueLoansDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Aging Analysis of Past Due Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>996017 - Disclosure - Loans and Allowance for Credit Losses - Aging Analysis of Past Due Loans (Parenthetical) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesAgingAnalysisOfPastDueLoansParentheticalDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Aging Analysis of Past Due Loans (Parenthetical) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>996027 - Disclosure - Loans and Allowance for Credit Losses - Nonperforming Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesNonperformingAssetsDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Nonperforming Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>996037 - Disclosure - Loans and Allowance for Credit Losses - Nonperforming Assets (Parenthetical) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesNonperformingAssetsParentheticalDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Nonperforming Assets (Parenthetical) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>996047 - Disclosure - Loans and Allowance for Credit Losses - Risk Grade by Category of Loan and Year of Origination (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesRiskGradeByCategoryOfLoanAndYearOfOriginationDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Risk Grade by Category of Loan and Year of Origination (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>996067 - Disclosure - Loans and Allowance for Credit Losses - Risk Grade by Category of Loan and Year of Origination (Parenthetical) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesRiskGradeByCategoryOfLoanAndYearOfOriginationParentheticalDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Risk Grade by Category of Loan and Year of Origination (Parenthetical) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>996077 - Disclosure - Loans and Allowance for Credit Losses - Allowance for Credit Losses on Loans by Category of Loan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureLoansAndAllowanceForCreditLossesAllowanceForCreditLossesOnLoansByCategoryOfLoanDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Allowance for Credit Losses on Loans by Category of Loan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>996087 - Disclosure - Loans and Allowance for Credit Losses - Rollforward of Allowance for Credit Losses on Off-Balance Sheet Credit Exposures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesRollforwardOfAllowanceForCreditLossesOnOffbalanceSheetCreditExposuresDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Rollforward of Allowance for Credit Losses on Off-Balance Sheet Credit Exposures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>996097 - Disclosure - Loans and Allowance for Credit Losses - Schedule of Amortized Cost of Loans Experiencing Financial Difficulty and Modified (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureLoansAndAllowanceForCreditLossesScheduleOfAmortizedCostOfLoansExperiencingFinancialDifficultyAndModifiedDetails</Role>
      <ShortName>Loans and Allowance for Credit Losses - Schedule of Amortized Cost of Loans Experiencing Financial Difficulty and Modified (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>996127 - Disclosure - Fair Value - Fair Value Assets Measured on Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureFairValueFairValueAssetsMeasuredOnRecurringBasisDetails</Role>
      <ShortName>Fair Value - Fair Value Assets Measured on Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>996137 - Disclosure - Fair Value - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureFairValueAdditionalInformationDetails</Role>
      <ShortName>Fair Value - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>996147 - Disclosure - Fair Value - Summary of Carrying Values and Estimated Fair Values of Financial Instruments on Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureFairValueSummaryOfCarryingValuesAndEstimatedFairValuesOfFinancialInstrumentsOnRecurringBasisDetails</Role>
      <ShortName>Fair Value - Summary of Carrying Values and Estimated Fair Values of Financial Instruments on Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>996157 - Disclosure - Premises and Equipment - Schedule of Premises and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosurePremisesAndEquipmentScheduleOfPremisesAndEquipmentDetails</Role>
      <ShortName>Premises and Equipment - Schedule of Premises and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>996167 - Disclosure - Premises and Equipment - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosurePremisesAndEquipmentAdditionalInformationDetails</Role>
      <ShortName>Premises and Equipment - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>996177 - Disclosure - Deposits - Schedule of Certificates and Their Remaining Maturities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDepositsScheduleOfCertificatesAndTheirRemainingMaturitiesDetails</Role>
      <ShortName>Deposits - Schedule of Certificates and Their Remaining Maturities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>996187 - Disclosure - Deposits - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDepositsAdditionalInformationDetails</Role>
      <ShortName>Deposits - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>996197 - Disclosure - Other Borrowings and Securities Sold Under Repurchase Agreements - Schedule of Other Borrowings and Securities Sold Under Repurchase Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreementsScheduleOfOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreementsDetai</Role>
      <ShortName>Other Borrowings and Securities Sold Under Repurchase Agreements - Schedule of Other Borrowings and Securities Sold Under Repurchase Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>996207 - Disclosure - Other Borrowings and Securities Sold Under Repurchase Agreements (Bank Term Funding Program) - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreementsBankTermFundingProgramAdditionalInformationDetails</Role>
      <ShortName>Other Borrowings and Securities Sold Under Repurchase Agreements (Bank Term Funding Program) - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreementsTables</ParentRole>
      <Position>84</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>996217 - Disclosure - Other Borrowings and Securities Sold Under Repurchase Agreements (FHLB advances and long-term notes payable) - Additional Information (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreementsFHLBAdvancesAndLongTermNotesPayableAdditionalInformationDetails</Role>
      <ShortName>Other Borrowings and Securities Sold Under Repurchase Agreements (FHLB advances and long-term notes payable) - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreementsTables</ParentRole>
      <Position>85</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>996227 - Disclosure - Other Borrowings and Securities Sold Under Repurchase Agreements (Securities sold under repurchase agreements with Company customers) - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreementsSecuritiesSoldUnderRepurchaseAgreementsWithCompanyCustomersAdditionalInformationDetails</Role>
      <ShortName>Other Borrowings and Securities Sold Under Repurchase Agreements (Securities sold under repurchase agreements with Company customers) - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherBorrowingsAndSecuritiesSoldUnderRepurchaseAgreementsTables</ParentRole>
      <Position>86</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>996247 - Disclosure - Income Taxes - Components of Income Tax Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesComponentsOfIncomeTaxExpenseDetails</Role>
      <ShortName>Income Taxes - Components of Income Tax Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>996257 - Disclosure - Income Taxes - Additional information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesAdditionalInformationDetails</Role>
      <ShortName>Income Taxes - Additional information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>996267 - Disclosure - Income Taxes - Schedule of Income Tax Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesScheduleOfIncomeTaxReconciliationDetails</Role>
      <ShortName>Income Taxes - Schedule of Income Tax Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>996277 - Disclosure - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesScheduleOfDeferredTaxAssetsAndLiabilitiesDetails</Role>
      <ShortName>Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>996287 - Disclosure - Stock Incentive Programs - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureStockIncentiveProgramsAdditionalInformationDetails</Role>
      <ShortName>Stock Incentive Programs - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>996297 - Disclosure - Stock Incentive Programs - Summary of the Status of Nonvested Shares of Restricted Stock (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureStockIncentiveProgramsSummaryOfStatusOfNonvestedSharesOfRestrictedStockDetails</Role>
      <ShortName>Stock Incentive Programs - Summary of the Status of Nonvested Shares of Restricted Stock (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>996307 - Disclosure - Other Noninterest Income and Expense - Other Noninterest Income and Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOtherNoninterestIncomeAndExpenseOtherNoninterestIncomeAndExpenseDetails</Role>
      <ShortName>Other Noninterest Income and Expense - Other Noninterest Income and Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>996317 - Disclosure - Profit Sharing Plan - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureProfitSharingPlanAdditionalInformationDetails</Role>
      <ShortName>Profit Sharing Plan - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>996327 - Disclosure - Off-balance Sheet Arrangements, Commitments and Contingencies - Summary of Future Cash Payments Associated with Contractual Obligations Pursuant to Bank Term Funding Program (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOffbalanceSheetArrangementsCommitmentsAndContingenciesSummaryOfFutureCashPaymentsAssociatedWithContractualObligationsPursuantToBan</Role>
      <ShortName>Off-balance Sheet Arrangements, Commitments and Contingencies - Summary of Future Cash Payments Associated with Contractual Obligations Pursuant to Bank Term Funding Program (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>996337 - Disclosure - Off-balance Sheet Arrangements, Commitments and Contingencies - Summary of Commitments Associated with Outstanding Standby Letters of Credit and Commitments to Extend Credit (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOffBalanceSheetArrangementsCommitmentsAndContingenciesSummaryOfCommitmentsAssociatedWithOutstandingStandbyLettersOfCreditAndCommitmentsToExtendCreditDetails</Role>
      <ShortName>Off-balance Sheet Arrangements, Commitments and Contingencies - Summary of Commitments Associated with Outstanding Standby Letters of Credit and Commitments to Extend Credit (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>996347 - Disclosure - Off-balance Sheet Arrangements, Commitments and Contingencies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOffBalanceSheetArrangementsCommitmentsAndContingenciesAdditionalInformationDetails</Role>
      <ShortName>Off-balance Sheet Arrangements, Commitments and Contingencies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>996357 - Disclosure - Off-balance Sheet Arrangements, Commitments and Contingencies - Future Undiscounted Cash Payments Associated with its Operating Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureOffBalanceSheetArrangementsCommitmentsAndContingenciesFutureUndiscountedCashPaymentsAssociatedWithItsOperatingLeasesDetails</Role>
      <ShortName>Off-balance Sheet Arrangements, Commitments and Contingencies - Future Undiscounted Cash Payments Associated with its Operating Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>996367 - Disclosure - Other Comprehensive (Loss) Income - Tax Effects Allocated to Each Component of Other Comprehensive (Loss) Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherComprehensiveLossIncomeTaxEffectsAllocatedToEachComponentOfOtherComprehensiveLossIncomeDetails</Role>
      <ShortName>Other Comprehensive (Loss) Income - Tax Effects Allocated to Each Component of Other Comprehensive (Loss) Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherComprehensiveLossIncomeTables</ParentRole>
      <Position>99</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>996377 - Disclosure - Other Comprehensive (Loss) Income - Activity in Accumulated Other Comprehensive (Loss) Income, Net of Tax (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherComprehensiveLossIncomeActivityInAccumulatedOtherComprehensiveLossIncomeNetOfTaxDetails</Role>
      <ShortName>Other Comprehensive (Loss) Income - Activity in Accumulated Other Comprehensive (Loss) Income, Net of Tax (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureOtherComprehensiveLossIncomeTables</ParentRole>
      <Position>100</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>996387 - Disclosure - Derivative Financial Instruments - Schedule of Notional Balances and Fair Value of Derivative Positions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDerivativeFinancialInstrumentsScheduleOfNotionalBalancesAndFairValueOfDerivativePositionsDetails</Role>
      <ShortName>Derivative Financial Instruments - Schedule of Notional Balances and Fair Value of Derivative Positions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>101</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>996397 - Disclosure - Derivative Financial Instruments - Schedule of Weighted Average Received and Paid Interest Rates for Interest Rate Swaps Outstanding (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDerivativeFinancialInstrumentsScheduleOfWeightedAverageReceivedAndPaidInterestRatesForInterestRateSwapsOutstandingDetails</Role>
      <ShortName>Derivative Financial Instruments - Schedule of Weighted Average Received and Paid Interest Rates for Interest Rate Swaps Outstanding (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>102</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>996407 - Disclosure - Derivative Financial Instruments - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDerivativeFinancialInstrumentsAdditionalInformationDetails</Role>
      <ShortName>Derivative Financial Instruments - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>103</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>996417 - Disclosure - Derivative Financial Instruments - Schedule of Income (Loss) from Derivatives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureDerivativeFinancialInstrumentsScheduleOfIncomeLossFromDerivativesDetails</Role>
      <ShortName>Derivative Financial Instruments - Schedule of Income (Loss) from Derivatives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>104</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>996427 - Disclosure - Regulatory Matters - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureRegulatoryMattersAdditionalInformationDetails</Role>
      <ShortName>Regulatory Matters - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>105</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>996437 - Disclosure - Regulatory Matters - Capital Ratios (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureRegulatoryMattersCapitalRatiosDetails</Role>
      <ShortName>Regulatory Matters - Capital Ratios (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>106</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>996447 - Disclosure - Parent Company Only Financial Statements - Condensed Balance Sheets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureParentCompanyOnlyFinancialStatementsCondensedBalanceSheetsDetails</Role>
      <ShortName>Parent Company Only Financial Statements - Condensed Balance Sheets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>107</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>996457 - Disclosure - Parent Company Only Financial Statements - Condensed Statements of Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureParentCompanyOnlyFinancialStatementsCondensedStatementsOfIncomeDetails</Role>
      <ShortName>Parent Company Only Financial Statements - Condensed Statements of Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>996467 - Disclosure - Parent Company Only Financial Statements - Condensed Statements of Comprehensive Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureParentCompanyOnlyFinancialStatementsCondensedStatementsOfComprehensiveIncomeDetails</Role>
      <ShortName>Parent Company Only Financial Statements - Condensed Statements of Comprehensive Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>109</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>996477 - Disclosure - Parent Company Only Financial Statements - Condensed Statements of Cash Flows (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/Role_DisclosureParentCompanyOnlyFinancialStatementsCondensedStatementsOfCashFlowsDetails</Role>
      <ShortName>Parent Company Only Financial Statements - Condensed Statements of Cash Flows (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="pb-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>996487 - Disclosure - Subsequent Events - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.prosperitybankusa.com/20251231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails</Role>
      <ShortName>Subsequent Events - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>111</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-K" isDefinitelyFs="true" isUsgaap="true" original="pb-20251231.htm">pb-20251231.htm</File>
    <File>pb-20251231.xsd</File>
  </InputFiles>
  <SupplementalFiles>
    <File>img149291694_0.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="8">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="1695">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="11">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="40">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="6">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
