<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>559</ContextCount>
  <ElementCount>558</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>198</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>10</UnitCount>
  <MyReports>
    <Report instance="alur-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.allurion.com/20251231/taxonomy/role/Role_DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="alur-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.allurion.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="alur-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.allurion.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>75030 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfOperations</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>75040 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveLoss</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>75050 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS' DEFICIT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfStockholdersDeficit</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF STOCKHOLDERS' DEFICIT</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>75060 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>75070 - Disclosure - Cybersecurity Risk Management, Strategy, and Governance</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCybersecurityRiskManagementStrategyAndGovernance</Role>
      <ShortName>Cybersecurity Risk Management, Strategy, and Governance</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="alur-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="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995443 - Disclosure - Award Timing Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/AwardTimingDisclosure</Role>
      <ShortName>Award Timing Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.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>11</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.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>12</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995457 - Disclosure - Organization and Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureOrganizationAndBasisOfPresentation</Role>
      <ShortName>Organization and Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995467 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995487 - Disclosure - Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureRevenue</Role>
      <ShortName>Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995497 - Disclosure - Inventory</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureInventory</Role>
      <ShortName>Inventory</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995507 - Disclosure - Property and Equipment, net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNet</Role>
      <ShortName>Property and Equipment, net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995517 - Disclosure - Accrued Expenses and Other Current Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureAccruedExpensesAndOtherCurrentLiabilities</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995527 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureDebt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995537 - Disclosure - Revenue Interest Financing, Side Letter, and PIPE Conversion Option</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureRevenueInterestFinancingSideLetterAndPipeConversionOption</Role>
      <ShortName>Revenue Interest Financing, Side Letter, and PIPE Conversion Option</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995547 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureFairValueMeasurements1</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995557 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureIncomeTaxes1</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995567 - Disclosure - Capital Stock and Stockholders' Deficit</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCapitalStockAndStockholdersDeficit1</Role>
      <ShortName>Capital Stock and Stockholders' Deficit</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995577 - Disclosure - Net Loss per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureNetLossPerShare1</Role>
      <ShortName>Net Loss per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995587 - Disclosure - Stock Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureStockBasedCompensation</Role>
      <ShortName>Stock Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995597 - Disclosure - Employee Benefit Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureEmployeeBenefitPlan1</Role>
      <ShortName>Employee Benefit Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995607 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995617 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSegmentInformation1</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995627 - Disclosure - Related-party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureRelatedpartyTransactions</Role>
      <ShortName>Related-party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995637 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995647 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995657 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995677 - Disclosure - Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureRevenueTables</Role>
      <ShortName>Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureRevenue</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995687 - Disclosure - Inventory (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureInventoryTables</Role>
      <ShortName>Inventory (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureInventory</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995697 - Disclosure - Property and Equipment, net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetTables</Role>
      <ShortName>Property and Equipment, net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNet</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995707 - Disclosure - Accrued Expenses and Other Current Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureAccruedExpensesAndOtherCurrentLiabilitiesTables</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureAccruedExpensesAndOtherCurrentLiabilities</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995717 - Disclosure - Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureDebtTables</Role>
      <ShortName>Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureDebt</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995737 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureFairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureFairValueMeasurements1</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995747 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureIncomeTaxes1</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995757 - Disclosure - Capital Stock and Stockholders' Deficit (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCapitalStockAndStockholdersDeficitTables</Role>
      <ShortName>Capital Stock and Stockholders' Deficit (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureCapitalStockAndStockholdersDeficit1</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995767 - Disclosure - Net Loss per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureNetLossPerShareTables</Role>
      <ShortName>Net Loss per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureNetLossPerShare1</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995777 - Disclosure - Stock Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureStockBasedCompensationTables</Role>
      <ShortName>Stock Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureStockBasedCompensation</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995787 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingencies</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995797 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.allurion.com/20251231/taxonomy/role/DisclosureSegmentInformation1</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995817 - Disclosure - Organization and Basis of Presentation - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureOrganizationAndBasisOfPresentationAdditionalInformationDetails</Role>
      <ShortName>Organization and Basis of Presentation - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995827 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995837 - Disclosure - Summary of Significant Accounting Policies - Summary of Risk of Concentration of Credit, Significant Customers (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesSummaryOfRiskOfConcentrationOfCreditSignificantCustomersDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Summary of Risk of Concentration of Credit, Significant Customers (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995847 - Disclosure - Summary of Significant Accounting Policies - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesReconciliationOfCashAndCashEquivalentsAndRestrictedCashDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995857 - Disclosure - Summary of Significant Accounting Policies - Summary of Activity in Allowance for Doubtful Accounts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesSummaryOfActivityInAllowanceForDoubtfulAccountsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Summary of Activity in Allowance for Doubtful Accounts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995867 - Disclosure - Revenue - Schedule of Revenues by Geographic Region (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfRevenuesByGeographicRegionDetails</Role>
      <ShortName>Revenue - Schedule of Revenues by Geographic Region (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995877 - Disclosure - Revenue - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureRevenueAdditionalInformationDetails</Role>
      <ShortName>Revenue - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995887 - Disclosure - Inventory - Schedule of Inventory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureInventoryScheduleOfInventoryDetails</Role>
      <ShortName>Inventory - Schedule of Inventory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995897 - Disclosure - Inventory - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureInventoryAdditionalInformationDetails</Role>
      <ShortName>Inventory - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995907 - Disclosure - Property and Equipment, net - Schedule of Property and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentDetails</Role>
      <ShortName>Property and Equipment, net - Schedule of Property and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>995917 - Disclosure - Property and Equipment, net - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetAdditionalInformationDetails</Role>
      <ShortName>Property and Equipment, net - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>995927 - Disclosure - Property and Equipment, net - Schedule of Depreciation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetScheduleOfDepreciationExpenseDetails</Role>
      <ShortName>Property and Equipment, net - Schedule of Depreciation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>995937 - Disclosure - Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureAccruedExpensesAndOtherCurrentLiabilitiesScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesDetails</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>995957 - Disclosure - Accrued Expenses and Other Current Liabilities - Schedule of Activity in Restructuring Accrual (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureAccruedExpensesAndOtherCurrentLiabilitiesScheduleOfActivityInRestructuringAccrualDetails</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities - Schedule of Activity in Restructuring Accrual (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>995967 - Disclosure - Debt - Summary of Components of Third-Party Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureDebtSummaryOfComponentsOfThirdpartyDebtDetails</Role>
      <ShortName>Debt - Summary of Components of Third-Party Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>995977 - Disclosure - Debt - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureDebtAdditionalInformationDetails</Role>
      <ShortName>Debt - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>995987 - Disclosure - Revenue Interest Financing, Side Letter, and PIPE Conversion Option - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureRevenueInterestFinancingSideLetterAndPipeConversionOptionAdditionalInformationDetails</Role>
      <ShortName>Revenue Interest Financing, Side Letter, and PIPE Conversion Option - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>995997 - Disclosure - Fair Value Measurements - Schedule of Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value at Issuance Date and on Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfFairValueHierarchyForAssetsAndLiabilitiesMeasuredAtFairValueAtIssuanceDateAndOnRecurringBasis</Role>
      <ShortName>Fair Value Measurements - Schedule of Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value at Issuance Date and on Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>996007 - Disclosure - Fair Value Measurements - Schedule of Assumptions used in Pricing Model (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfAssumptionsUsedInPricingModelDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Assumptions used in Pricing Model (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>996017 - Disclosure - Fair Value Measurements - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetails</Role>
      <ShortName>Fair Value Measurements - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>996027 - Disclosure - Fair Value Measurements - Schedule of Changes in Fair Values (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfChangesInFairValuesDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Changes in Fair Values (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>996037 - Disclosure - Fair Value Measurements - Schedule of Estimated Fair Value was Measured Using a Monte Carlo Simulation Method (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfEstimatedFairValueWasMeasuredUsingAMonteCarloSimulationMethodDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Estimated Fair Value was Measured Using a Monte Carlo Simulation Method (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>996047 - Disclosure - Income Taxes - Domestic and Foreign Components of Loss Before Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureIncomeTaxesDomesticAndForeignComponentsOfLossBeforeIncomeTaxesDetails</Role>
      <ShortName>Income Taxes - Domestic and Foreign Components of Loss Before Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>996057 - Disclosure - Income Taxes - Components of Provision for Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureIncomeTaxesComponentsOfProvisionForIncomeTaxesDetails</Role>
      <ShortName>Income Taxes - Components of Provision for Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>996067 - Disclosure - Income Taxes - Reconciliation of Effective Tax Rate and Statutory Federal Income Tax Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureIncomeTaxesReconciliationOfEffectiveTaxRateAndStatutoryFederalIncomeTaxRateDetails</Role>
      <ShortName>Income Taxes - Reconciliation of Effective Tax Rate and Statutory Federal Income Tax Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>996077 - Disclosure - Income Taxes - Schedule of Deferred Tax Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfDeferredTaxAssetsDetails</Role>
      <ShortName>Income Taxes - Schedule of Deferred Tax Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>996097 - Disclosure - Income Taxes - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails</Role>
      <ShortName>Income Taxes - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>996107 - Disclosure - Income Taxes - Summary of Valuation Allowance (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfValuationAllowanceDetails</Role>
      <ShortName>Income Taxes - Summary of Valuation Allowance (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>996117 - Disclosure - Capital Stock and Stockholders' Deficit - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCapitalStockAndStockholdersDeficitAdditionalInformationDetails</Role>
      <ShortName>Capital Stock and Stockholders' Deficit - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>996127 - Disclosure - Capital Stock and Stockholders' Deficit - Summary of Reserved for Issuance Upon the Potential Conversion or Exercise (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCapitalStockAndStockholdersDeficitSummaryOfReservedForIssuanceUponThePotentialConversionOrExerciseDetails</Role>
      <ShortName>Capital Stock and Stockholders' Deficit - Summary of Reserved for Issuance Upon the Potential Conversion or Exercise (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>996137 - Disclosure - Capital Stock and Stockholders' Deficit - Summary of Warrants to Purchase Classes of Preferred Stock and Common Stock Outstanding (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCapitalStockAndStockholdersDeficitSummaryOfWarrantsToPurchaseClassesOfPreferredStockAndCommonStockOutstandingDetails</Role>
      <ShortName>Capital Stock and Stockholders' Deficit - Summary of Warrants to Purchase Classes of Preferred Stock and Common Stock Outstanding (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>996147 - Disclosure - Net Loss per Share - Summary of Basic and Diluted Net Loss per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureNetLossPerShareSummaryOfBasicAndDilutedNetLossPerShareDetails</Role>
      <ShortName>Net Loss per Share - Summary of Basic and Diluted Net Loss per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>996157 - Disclosure - Net Loss per Share - Summary of Dilutive Securities Excluded from Computation of Basic and Diluted Net Loss Per Common Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureNetLossPerShareSummaryOfDilutiveSecuritiesExcludedFromComputationOfBasicAndDilutedNetLossPerCommonShareDetails</Role>
      <ShortName>Net Loss per Share - Summary of Dilutive Securities Excluded from Computation of Basic and Diluted Net Loss Per Common Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>996167 - Disclosure - Stock Based Compensation - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetails</Role>
      <ShortName>Stock Based Compensation - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>996177 - Disclosure - Stock Based Compensation - Schedule of Stock Based Compensation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationDetails</Role>
      <ShortName>Stock Based Compensation - Schedule of Stock Based Compensation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>996187 - Disclosure - Stock Based Compensation - Summary of Stock Option Activity Under the Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStockOptionActivityUnderThePlanDetails</Role>
      <ShortName>Stock Based Compensation - Summary of Stock Option Activity Under the Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>996197 - Disclosure - Stock Based Compensation - Schedule of Assumptions used in Black-Scholes Option-Pricing Model (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureStockBasedCompensationScheduleOfAssumptionsUsedInBlackscholesOptionpricingModelDetails</Role>
      <ShortName>Stock Based Compensation - Schedule of Assumptions used in Black-Scholes Option-Pricing Model (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>996207 - Disclosure - Stock Based Compensation - Summary of Restricted Stock Unit Activity Under the Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureStockBasedCompensationSummaryOfRestrictedStockUnitActivityUnderThePlanDetails</Role>
      <ShortName>Stock Based Compensation - Summary of Restricted Stock Unit Activity Under the Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>996217 - Disclosure - Employee Benefit Plan - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureEmployeeBenefitPlanAdditionalInformationDetails</Role>
      <ShortName>Employee Benefit Plan - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>996227 - Disclosure - Commitments and Contingencies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>996237 - Disclosure - Commitments and Contingencies - Schedule of Other Pertinent Lease Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesScheduleOfOtherPertinentLeaseInformationDetails</Role>
      <ShortName>Commitments and Contingencies - Schedule of Other Pertinent Lease Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>996247 - Disclosure - Commitments and Contingencies - Schedule of Future Commitments Under Non-cancelable Operating Lease Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesScheduleOfFutureCommitmentsUnderNoncancelableOperatingLeaseAgreementsDetails3</Role>
      <ShortName>Commitments and Contingencies - Schedule of Future Commitments Under Non-cancelable Operating Lease Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>996267 - Disclosure - Commitments and Contingencies - Schedule of Weighted-Average Remaining Lease Terms and Discount Rates Related Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesScheduleOfWeightedaverageRemainingLeaseTermsAndDiscountRatesRelatedLeasesDetails</Role>
      <ShortName>Commitments and Contingencies - Schedule of Weighted-Average Remaining Lease Terms and Discount Rates Related Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>996287 - Disclosure - Segment Information - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetails</Role>
      <ShortName>Segment Information - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>996297 - Disclosure - Segment Information - Schedule of Significant Segment Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSegmentInformationScheduleOfSignificantSegmentExpensesDetails</Role>
      <ShortName>Segment Information - Schedule of Significant Segment Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>996307 - Disclosure - Segment Information - Schedule of Long-lived Assets by Geography (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSegmentInformationScheduleOfLonglivedAssetsByGeographyDetails</Role>
      <ShortName>Segment Information - Schedule of Long-lived Assets by Geography (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>996317 - Disclosure - Related-party Transactions - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureRelatedpartyTransactionsAdditionalInformationDetails</Role>
      <ShortName>Related-party Transactions - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="alur-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>996327 - Disclosure - Subsequent Events - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.allurion.com/20251231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails</Role>
      <ShortName>Subsequent Events - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</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="alur-20251231.htm">alur-20251231.htm</File>
    <File>alur-20251231.xsd</File>
  </InputFiles>
  <SupplementalFiles>
    <File>img32663640_0.jpg</File>
    <File>img32663640_1.jpg</File>
    <File>img32663640_2.jpg</File>
    <File>img32663640_3.jpg</File>
    <File>img32663640_4.jpg</File>
    <File>img32663640_5.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="1099">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="13">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="40">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="11">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
