<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.4</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>164</ContextCount>
  <ElementCount>359</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>63</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report instance="arct-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://arcturusrx.com/20251231/taxonomy/role/Role_DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>75010 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_StatementCONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="arct-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://arcturusrx.com/20251231/taxonomy/role/Role_StatementCONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>75030 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE (LOSS) INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfOperationsAndComprehensiveLossIncome</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE (LOSS) INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>75040 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_StatementCONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITY</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>75050 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_StatementCONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>75060 - Disclosure - Cybersecurity Risk Management, Strategy, and Governance</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureCybersecurityRiskManagementStrategyAndGovernance</Role>
      <ShortName>Cybersecurity Risk Management, Strategy, and Governance</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.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>8</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.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>9</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995455 - Disclosure - Organization</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureOrganization</Role>
      <ShortName>Organization</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995465 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995475 - Disclosure - Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureRevenue</Role>
      <ShortName>Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995485 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureFairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995495 - Disclosure - Accrued Liabilities Detail</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureAccruedLiabilitiesDetail</Role>
      <ShortName>Accrued Liabilities Detail</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995505 - Disclosure - Property and Equipment, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNet</Role>
      <ShortName>Property and Equipment, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995515 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureDebt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995525 - Disclosure - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureStockholdersEquity</Role>
      <ShortName>Stockholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995535 - Disclosure - Share-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensation</Role>
      <ShortName>Share-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995545 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995555 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995565 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureSegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995575 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureRelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995585 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995595 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995605 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995615 - Disclosure - Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureRevenueTables</Role>
      <ShortName>Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureRevenue</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995625 - Disclosure - Accrued Liabilities Detail (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureAccruedLiabilitiesDetailTables</Role>
      <ShortName>Accrued Liabilities Detail (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/DisclosureAccruedLiabilitiesDetail</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995635 - Disclosure - Property and Equipment, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNetTables</Role>
      <ShortName>Property and Equipment, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNet</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995655 - Disclosure - Share-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensationTables</Role>
      <ShortName>Share-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensation</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995665 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxes</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995675 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureCommitmentsAndContingencies</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995685 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureSegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/DisclosureSegmentInformation</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995695 - Disclosure - Organization (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureOrganizationDetailsTextual</Role>
      <ShortName>Organization (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureOrganization</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995705 - Disclosure - Summary of Significant Accounting Policies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesDetailsTextual</Role>
      <ShortName>Summary of Significant Accounting Policies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995715 - Disclosure - Summary of Significant Accounting Policies - Schedule of Cash and Cash Equivalents and Restricted Cash (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfCashAndCashEquivalentsAndRestrictedCashDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Schedule of Cash and Cash Equivalents and Restricted Cash (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995725 - Disclosure - Revenue - Summary of Changes in Balances of Receivables and Contract Liability (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureRevenueSummaryOfChangesInBalancesOfReceivablesAndContractLiabilityDetails</Role>
      <ShortName>Revenue - Summary of Changes in Balances of Receivables and Contract Liability (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995735 - Disclosure - Revenue (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureRevenueDetailsTextual</Role>
      <ShortName>Revenue (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureRevenueTables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995745 - Disclosure - Revenue - Summary of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureRevenueSummaryOfRevenueDetails</Role>
      <ShortName>Revenue - Summary of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995755 - Disclosure - Revenue - Schedule of Accounts Receivable (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfAccountsReceivableDetails</Role>
      <ShortName>Revenue - Schedule of Accounts Receivable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995775 - Disclosure - Fair Value Measurements (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureFairValueMeasurementsDetailsTextual</Role>
      <ShortName>Fair Value Measurements (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureFairValueMeasurements</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995785 - Disclosure - Accrued Liabilities Detail - Schedule of Accrued Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureAccruedLiabilitiesDetailScheduleOfAccruedLiabilitiesDetails</Role>
      <ShortName>Accrued Liabilities Detail - Schedule of Accrued Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995795 - Disclosure - Property and Equipment, Net - Summary of Components of Property and Equipment, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetSummaryOfComponentsOfPropertyAndEquipmentNetDetails</Role>
      <ShortName>Property and Equipment, Net - Summary of Components of Property and Equipment, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995805 - Disclosure - Property and Equipment, Net (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNetDetailsTextual</Role>
      <ShortName>Property and Equipment, Net (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNetTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995815 - Disclosure - Debt (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureDebtDetailsTextual</Role>
      <ShortName>Debt (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureDebt</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995825 - Disclosure - Stockholders' Equity (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureStockholdersEquityDetailsTextual</Role>
      <ShortName>Stockholders' Equity (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureStockholdersEquity</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995835 - Disclosure - Share-Based Compensation (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensationDetailsTextual</Role>
      <ShortName>Share-Based Compensation (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensationTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995845 - Disclosure - Share-Based Compensation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensationDetails</Role>
      <ShortName>Share-Based Compensation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensationTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995855 - Disclosure - Share-Based Compensation (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensationDetails1</Role>
      <ShortName>Share-Based Compensation (Details 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensationTables</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995865 - Disclosure - Share-Based Compensation - (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureSharebasedCompensationDetails2</Role>
      <ShortName>Share-Based Compensation - (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensationTables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995875 - Disclosure - Share-Based Compensation (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureSharebasedCompensationDetails3</Role>
      <ShortName>Share-Based Compensation (Details 3)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureShareBasedCompensationTables</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995885 - Disclosure - Income Taxes (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesDetails1</Role>
      <ShortName>Income Taxes (Details 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesTables</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995895 - Disclosure - Income Taxes (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureIncomeTaxesDetails2</Role>
      <ShortName>Income Taxes (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesTables</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995905 - Disclosure - Income Taxes (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureIncomeTaxesDetails3</Role>
      <ShortName>Income Taxes (Details 3)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesTables</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995915 - Disclosure - Income Taxes (Details 4)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureIncomeTaxesDetails4</Role>
      <ShortName>Income Taxes (Details 4)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesTables</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>995925 - Disclosure - Income Taxes (Details 5)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureIncomeTaxesDetails5</Role>
      <ShortName>Income Taxes (Details 5)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesTables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>995935 - Disclosure - Income Taxes (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesDetailsTextual</Role>
      <ShortName>Income Taxes (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>995945 - Disclosure - Income Taxes (Details 6)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureIncomeTaxesDetails6</Role>
      <ShortName>Income Taxes (Details 6)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureIncomeTaxesTables</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>995955 - Disclosure - Commitments and Contingencies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesDetailsTextual</Role>
      <ShortName>Commitments and Contingencies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://arcturusrx.com/20251231/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesTables</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>995965 - Disclosure - Commitments and Contingencies - Remaining Payments of Operating Lease Liability (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesRemainingPaymentsOfOperatingLeaseLiabilityDetails</Role>
      <ShortName>Commitments and Contingencies - Remaining Payments of Operating Lease Liability (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>995985 - Disclosure - Segment Information - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetails</Role>
      <ShortName>Segment Information - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>995995 - Disclosure - Segment Information - Summary of Reported Segment Revenues, Segment Loss and Income, and Significant Segment Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureSegmentInformationSummaryOfReportedSegmentRevenuesSegmentLossAndIncomeAndSignificantSegmentExpensesDetails</Role>
      <ShortName>Segment Information - Summary of Reported Segment Revenues, Segment Loss and Income, and Significant Segment Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="arct-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>996005 - Disclosure - Segment Information - Summary of Reported Segment Revenues, Segment Loss and Income, and Significant Segment Expenses (Parenthetical) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://arcturusrx.com/20251231/taxonomy/role/DisclosureSegmentInformationSummaryOfReportedSegmentRevenuesSegmentLossAndIncomeAndSignificantSegmentExpensesParentheticalDetails</Role>
      <ShortName>Segment Information - Summary of Reported Segment Revenues, Segment Loss and Income, and Significant Segment Expenses (Parenthetical) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</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="arct-20251231.htm">arct-20251231.htm</File>
    <File>arct-20251231.xsd</File>
  </InputFiles>
  <SupplementalFiles>
    <File>img229357118_0.gif</File>
    <File>img229357118_1.jpg</File>
    <File>img229357118_10.gif</File>
    <File>img229357118_11.jpg</File>
    <File>img229357118_2.jpg</File>
    <File>img229357118_3.jpg</File>
    <File>img229357118_4.jpg</File>
    <File>img229357118_5.jpg</File>
    <File>img229357118_6.jpg</File>
    <File>img229357118_7.gif</File>
    <File>img229357118_8.gif</File>
    <File>img229357118_9.gif</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="590">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="15">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="39">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="5">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
