<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.3</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>194</ContextCount>
  <ElementCount>324</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>53</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>9952151 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>9952152 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>9952153 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVELOSSINCOME</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>9952154 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>9952155 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>9952156 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/SummaryofSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>9952157 - Disclosure - Marketable Securities and Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/MarketableSecuritiesandFairValueMeasurements</Role>
      <ShortName>Marketable Securities and Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>9952158 - Disclosure - Acquisitions and Divestitures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/AcquisitionsandDivestitures</Role>
      <ShortName>Acquisitions and Divestitures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>9952159 - Disclosure - Restructuring Activities and Other Charges</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/RestructuringActivitiesandOtherCharges</Role>
      <ShortName>Restructuring Activities and Other Charges</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>9952160 - Disclosure - Revenue Recognition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/RevenueRecognition</Role>
      <ShortName>Revenue Recognition</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>9952161 - Disclosure - Goodwill and Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/GoodwillandIntangibleAssets</Role>
      <ShortName>Goodwill and Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>9952162 - Disclosure - Condensed Consolidated Balance Sheets Detail</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CondensedConsolidatedBalanceSheetsDetail</Role>
      <ShortName>Condensed Consolidated Balance Sheets Detail</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>9952163 - Disclosure - Convertible Senior Notes</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.repligencorp.com/role/ConvertibleSeniorNotes</Role>
      <ShortName>Convertible Senior Notes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>9952164 - Disclosure - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/StockholdersEquity</Role>
      <ShortName>Stockholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>9952165 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>9952166 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>9952167 - Disclosure - (Loss) Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/LossEarningsPerShare</Role>
      <ShortName>(Loss) Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>9952168 - Disclosure - Segment Reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/SegmentReporting</Role>
      <ShortName>Segment Reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>9952169 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.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>21</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>9955511 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/SummaryofSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>9955512 - Disclosure - Marketable Securities and Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/MarketableSecuritiesandFairValueMeasurementsTables</Role>
      <ShortName>Marketable Securities and Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/MarketableSecuritiesandFairValueMeasurements</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>9955513 - Disclosure - Acquisitions and Divestitures (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/AcquisitionsandDivestituresTables</Role>
      <ShortName>Acquisitions and Divestitures (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/AcquisitionsandDivestitures</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>9955514 - Disclosure - Restructuring Activities and Other Charges (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/RestructuringActivitiesandOtherChargesTables</Role>
      <ShortName>Restructuring Activities and Other Charges (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/RestructuringActivitiesandOtherCharges</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>9955515 - Disclosure - Revenue Recognition (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/RevenueRecognitionTables</Role>
      <ShortName>Revenue Recognition (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/RevenueRecognition</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>9955516 - Disclosure - Goodwill and Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/GoodwillandIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/GoodwillandIntangibleAssets</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>9955517 - Disclosure - Condensed Consolidated Balance Sheets Detail (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CondensedConsolidatedBalanceSheetsDetailTables</Role>
      <ShortName>Condensed Consolidated Balance Sheets Detail (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/CondensedConsolidatedBalanceSheetsDetail</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>9955518 - Disclosure - Convertible Senior Notes (Tables)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.repligencorp.com/role/ConvertibleSeniorNotesTables</Role>
      <ShortName>Convertible Senior Notes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/ConvertibleSeniorNotes</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>9955519 - Disclosure - Stockholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/StockholdersEquityTables</Role>
      <ShortName>Stockholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/StockholdersEquity</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>9955520 - Disclosure - (Loss) Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/LossEarningsPerShareTables</Role>
      <ShortName>(Loss) Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/LossEarningsPerShare</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>9955521 - Disclosure - Segment Reporting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/SegmentReportingTables</Role>
      <ShortName>Segment Reporting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/SegmentReporting</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>9955522 - Disclosure - Marketable Securities and Fair Value Measurements - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/MarketableSecuritiesandFairValueMeasurementsNarrativeDetail</Role>
      <ShortName>Marketable Securities and Fair Value Measurements - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/MarketableSecuritiesandFairValueMeasurementsTables</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>9955523 - Disclosure - Marketable Securities and Fair Value Measurements - Summary of Marketable Securities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/MarketableSecuritiesandFairValueMeasurementsSummaryofMarketableSecuritiesDetail</Role>
      <ShortName>Marketable Securities and Fair Value Measurements - Summary of Marketable Securities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>9955524 - Disclosure - Marketable Securities and Fair Value Measurements - Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/MarketableSecuritiesandFairValueMeasurementsScheduleofFinancialAssetsandFinancialLiabilitiesMeasuredatFairValueonaRecurringBasisDetails</Role>
      <ShortName>Marketable Securities and Fair Value Measurements - Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>9955525 - Disclosure - Marketable Securities and Fair Value Measurements - Schedule of Reconciliation of the Change in the Fair Value of Contingent Consideration - Earnout (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/MarketableSecuritiesandFairValueMeasurementsScheduleofReconciliationoftheChangeintheFairValueofContingentConsiderationEarnoutDetail</Role>
      <ShortName>Marketable Securities and Fair Value Measurements - Schedule of Reconciliation of the Change in the Fair Value of Contingent Consideration - Earnout (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>9955526 - Disclosure - Acquisitions and Divestitures - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/AcquisitionsandDivestituresNarrativeDetail</Role>
      <ShortName>Acquisitions and Divestitures - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>9955527 - Disclosure - Acquisitions and Divestitures - Fair Value of Net Assets Acquired (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/AcquisitionsandDivestituresFairValueofNetAssetsAcquiredDetail</Role>
      <ShortName>Acquisitions and Divestitures - Fair Value of Net Assets Acquired (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>9955528 - Disclosure - Acquisitions and Divestitures - Estimated Useful Life and Fair Value (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/AcquisitionsandDivestituresEstimatedUsefulLifeandFairValueDetail</Role>
      <ShortName>Acquisitions and Divestitures - Estimated Useful Life and Fair Value (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>9955529 - Disclosure - Restructuring Activities and Other Charges - Summary of Charges Related to Restructuring Activities and Other Charges by Type of Cost (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/RestructuringActivitiesandOtherChargesSummaryofChargesRelatedtoRestructuringActivitiesandOtherChargesbyTypeofCostDetail</Role>
      <ShortName>Restructuring Activities and Other Charges - Summary of Charges Related to Restructuring Activities and Other Charges by Type of Cost (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>9955530 - Disclosure - Restructuring Activities and Other Charges - Summary of Changes in the Company's Accrued Restructuring Balance (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/RestructuringActivitiesandOtherChargesSummaryofChangesintheCompanysAccruedRestructuringBalanceDetail</Role>
      <ShortName>Restructuring Activities and Other Charges - Summary of Changes in the Company's Accrued Restructuring Balance (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>9955531 - Disclosure - Revenue Recognition - Summary of Disaggregation of Revenue (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/RevenueRecognitionSummaryofDisaggregationofRevenueDetail</Role>
      <ShortName>Revenue Recognition - Summary of Disaggregation of Revenue (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>9955532 - Disclosure - Revenue Recognition - Summary of Receivables and Deferred Revenue from Contracts with Customers (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/RevenueRecognitionSummaryofReceivablesandDeferredRevenuefromContractswithCustomersDetail</Role>
      <ShortName>Revenue Recognition - Summary of Receivables and Deferred Revenue from Contracts with Customers (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>9955533 - Disclosure - Revenue Recognition - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/RevenueRecognitionNarrativeDetail</Role>
      <ShortName>Revenue Recognition - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>9955534 - Disclosure - Goodwill and Intangible Assets - Change in Carrying Value of Goodwill (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/GoodwillandIntangibleAssetsChangeinCarryingValueofGoodwillDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Change in Carrying Value of Goodwill (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>9955535 - Disclosure - Goodwill and Intangible Assets - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/GoodwillandIntangibleAssetsNarrativeDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>9955536 - Disclosure - Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/GoodwillandIntangibleAssetsScheduleofIntangibleAssetsDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>9955537 - Disclosure - Goodwill and Intangible Assets - Amortization Expense for Amortized Intangible Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/GoodwillandIntangibleAssetsAmortizationExpenseforAmortizedIntangibleAssetsDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Amortization Expense for Amortized Intangible Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>9955538 - Disclosure - Condensed Consolidated Balance Sheets Detail - Schedule of Inventories (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CondensedConsolidatedBalanceSheetsDetailScheduleofInventoriesDetail</Role>
      <ShortName>Condensed Consolidated Balance Sheets Detail - Schedule of Inventories (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>9955539 - Disclosure - Condensed Consolidated Balance Sheets Detail - Schedule of Accrued Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/CondensedConsolidatedBalanceSheetsDetailScheduleofAccruedLiabilitiesDetail</Role>
      <ShortName>Condensed Consolidated Balance Sheets Detail - Schedule of Accrued Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>9955540 - Disclosure - Convertible Senior Notes - Carrying Value of Convertible Senior Notes (Detail)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.repligencorp.com/role/ConvertibleSeniorNotesCarryingValueofConvertibleSeniorNotesDetail</Role>
      <ShortName>Convertible Senior Notes - Carrying Value of Convertible Senior Notes (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>9955541 - Disclosure - Convertible Senior Notes - Narrative (Detail)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.repligencorp.com/role/ConvertibleSeniorNotesNarrativeDetail</Role>
      <ShortName>Convertible Senior Notes - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>9955542 - Disclosure - Convertible Senior Notes - Schedule of Convertible Note Interest Expense (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.repligencorp.com/role/ConvertibleSeniorNotesScheduleofConvertibleNoteInterestExpenseDetails</Role>
      <ShortName>Convertible Senior Notes - Schedule of Convertible Note Interest Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>9955543 - Disclosure - Stockholders' Equity - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/StockholdersEquityNarrativeDetail</Role>
      <ShortName>Stockholders' Equity - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>9955544 - Disclosure - Stockholders' Equity - Stock-Based Compensation Expense (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/StockholdersEquityStockBasedCompensationExpenseDetail</Role>
      <ShortName>Stockholders' Equity - Stock-Based Compensation Expense (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>9955545 - Disclosure - Stockholders' Equity - Summary of Option Activity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/StockholdersEquitySummaryofOptionActivityDetail</Role>
      <ShortName>Stockholders' Equity - Summary of Option Activity (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>9955546 - Disclosure - Stockholders' Equity - Summary of Restricted Stock Unit Activity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/StockholdersEquitySummaryofRestrictedStockUnitActivityDetail</Role>
      <ShortName>Stockholders' Equity - Summary of Restricted Stock Unit Activity (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>9955547 - Disclosure - Income Taxes - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/IncomeTaxesNarrativeDetail</Role>
      <ShortName>Income Taxes - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>9955548 - Disclosure - (Loss) Earnings Per Share - Reconciliation of Basic and Diluted Shares Amounts (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/LossEarningsPerShareReconciliationofBasicandDilutedSharesAmountsDetail</Role>
      <ShortName>(Loss) Earnings Per Share - Reconciliation of Basic and Diluted Shares Amounts (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>9955549 - Disclosure - (Loss) Earnings Per Share - Summary of Company's Potential Common Shares Excluded from the Computation of Diluted Earnings or Loss Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/LossEarningsPerShareSummaryofCompanysPotentialCommonSharesExcludedfromtheComputationofDilutedEarningsorLossPerShareDetail</Role>
      <ShortName>(Loss) Earnings Per Share - Summary of Company's Potential Common Shares Excluded from the Computation of Diluted Earnings or Loss Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>9955550 - Disclosure - Segment Reporting - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/SegmentReportingNarrativeDetail</Role>
      <ShortName>Segment Reporting - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>9955551 - Disclosure - Segment Reporting - Percentage of Revenue by Geographic Area (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/SegmentReportingPercentageofRevenuebyGeographicAreaDetail</Role>
      <ShortName>Segment Reporting - Percentage of Revenue by Geographic Area (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>9955552 - Disclosure - Segment Reporting - Schedule of Information about Reportable Segments (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/SegmentReportingScheduleofInformationaboutReportableSegmentsDetail</Role>
      <ShortName>Segment Reporting - Schedule of Information about Reportable Segments (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="rgen-20260930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>9955553 - Disclosure - Subsequent Events - (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.repligencorp.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events - (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.repligencorp.com/role/SubsequentEvents</ParentRole>
      <Position>64</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-Q" isDefinitelyFs="true" isUsgaap="true" original="rgen-20260930.htm">rgen-20260930.htm</File>
    <File>rgen-20260930.xsd</File>
    <File>rgen-20260930_cal.xml</File>
    <File>rgen-20260930_def.xml</File>
    <File>rgen-20260930_lab.xml</File>
    <File>rgen-20260930_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="885">http://fasb.org/us-gaap/2026</BaseTaxonomy>
    <BaseTaxonomy items="29">http://xbrl.sec.gov/dei/2026</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/ecd/2026</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
