<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>183</ContextCount>
  <ElementCount>356</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>74</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-document-and-entity-information</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>001 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-consolidated-balance-sheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>002 - Statement - Consolidated Balance Sheets (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-consolidated-balance-sheets-parentheticals</Role>
      <ShortName>Consolidated Balance Sheets (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>003 - Statement - Consolidated Statements of Operations and Comprehensive Loss</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-consolidated-statements-of-operations-and-comprehensive-loss</Role>
      <ShortName>Consolidated Statements of Operations and Comprehensive Loss</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>004 - Statement - Consolidated Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-consolidated-statements-of-changes-in-redeemable-convertible-preferred-stock-and-stockholders-equity-deficit</Role>
      <ShortName>Consolidated Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>005 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-consolidated-statements-of-cash-flows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.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>7</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.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>8</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.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>9</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure</Role>
      <ShortName>Cybersecurity Risk Management and Strategy Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995555 - Disclosure - Note 1 - Organization and Description of Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-1-organization-and-description-of-business</Role>
      <ShortName>Note 1 - Organization and Description of Business</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995556 - Disclosure - Note 2 - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-2-summary-of-significant-accounting-policies</Role>
      <ShortName>Note 2 - Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995557 - Disclosure - Note 3 - Other Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-3-other-current-assets</Role>
      <ShortName>Note 3 - Other Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995558 - Disclosure - Note 4 - Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-4-intangible-assets</Role>
      <ShortName>Note 4 - Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995559 - Disclosure - Note 5 - Accrued Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-5-accrued-liabilities-</Role>
      <ShortName>Note 5 - Accrued Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995560 - Disclosure - Note 6 - Convertible Promissory Note Due to Novartis</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-6-convertible-promissory-note-due-to-novartis</Role>
      <ShortName>Note 6 - Convertible Promissory Note Due to Novartis</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995561 - Disclosure - Note 7 - Promissory Notes Due to 3i, LP ("3i")</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-7-promissory-notes-due-to-3i-lp-3i-</Role>
      <ShortName>Note 7 - Promissory Notes Due to 3i, LP ("3i")</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995562 - Disclosure - Note 8 - Preferred Stock</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-8-preferred-stock-</Role>
      <ShortName>Note 8 - Preferred Stock</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995563 - Disclosure - Note 9 - Warrant Liability</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-9-warrant-liability</Role>
      <ShortName>Note 9 - Warrant Liability</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995564 - Disclosure - Note 10 - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-10-stockholders-equity</Role>
      <ShortName>Note 10 - Stockholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995565 - Disclosure - Note 11 - Stock-based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-11-stockbased-compensation</Role>
      <ShortName>Note 11 - Stock-based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995566 - Disclosure - Note 12 - License and Development Agreements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-12-license-and-development-agreements-</Role>
      <ShortName>Note 12 - License and Development Agreements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995567 - Disclosure - Note 13 - Income Tax</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-13-income-tax</Role>
      <ShortName>Note 13 - Income Tax</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995568 - Disclosure - Note 14 - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-14-commitments-and-contingencies</Role>
      <ShortName>Note 14 - Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995569 - Disclosure - Note 15 - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-15-subsequent-events</Role>
      <ShortName>Note 15 - Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995570 - Disclosure - Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-significant-accounting-policies-policies</Role>
      <ShortName>Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-2-summary-of-significant-accounting-policies</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995571 - Disclosure - Note 2 - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-2-summary-of-significant-accounting-policies-tables</Role>
      <ShortName>Note 2 - Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-2-summary-of-significant-accounting-policies</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995572 - Disclosure - Note 3 - Other Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-3-other-current-assets-tables</Role>
      <ShortName>Note 3 - Other Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-3-other-current-assets</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995573 - Disclosure - Note 4 - Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-4-intangible-assets-tables</Role>
      <ShortName>Note 4 - Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-4-intangible-assets</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995574 - Disclosure - Note 5 - Accrued Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-5-accrued-liabilities-tables</Role>
      <ShortName>Note 5 - Accrued Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-5-accrued-liabilities-</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995575 - Disclosure - Note 6 - Convertible Promissory Note Due to Novartis (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-6-convertible-promissory-note-due-to-novartis-tables</Role>
      <ShortName>Note 6 - Convertible Promissory Note Due to Novartis (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-6-convertible-promissory-note-due-to-novartis</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995576 - Disclosure - Note 8 - Preferred Stock (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-8-preferred-stock-tables</Role>
      <ShortName>Note 8 - Preferred Stock (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-8-preferred-stock-</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995577 - Disclosure - Note 9 - Warrant Liability (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-9-warrant-liability-tables</Role>
      <ShortName>Note 9 - Warrant Liability (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-9-warrant-liability</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995578 - Disclosure - Note 11 - Stock-based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-11-stockbased-compensation-tables</Role>
      <ShortName>Note 11 - Stock-based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-11-stockbased-compensation</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995579 - Disclosure - Note 13 - Income Tax (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-13-income-tax-tables</Role>
      <ShortName>Note 13 - Income Tax (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-13-income-tax</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995580 - Disclosure - Note 1 - Organization and Description of Business (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-1-organization-and-description-of-business-details-textual</Role>
      <ShortName>Note 1 - Organization and Description of Business (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-1-organization-and-description-of-business</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995581 - Disclosure - Note 2 - Summary of Significant Accounting Policies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-2-summary-of-significant-accounting-policies-details-textual</Role>
      <ShortName>Note 2 - Summary of Significant Accounting Policies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-2-summary-of-significant-accounting-policies-tables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995582 - Disclosure - Note 2 - Summary of Significant Accounting Policies - Estimated Useful Life of Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-2-summary-of-significant-accounting-policies-estimated-useful-life-of-assets-details</Role>
      <ShortName>Note 2 - Summary of Significant Accounting Policies - Estimated Useful Life of Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995583 - Disclosure - Note 2 - Summary of Significant Accounting Policies - Schedule of Antidilutive Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-2-summary-of-significant-accounting-policies-schedule-of-antidilutive-securities-details</Role>
      <ShortName>Note 2 - Summary of Significant Accounting Policies - Schedule of Antidilutive Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995584 - Disclosure - Note 3 - Other Current Assets - Other Current Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-3-other-current-assets-other-current-assets-details</Role>
      <ShortName>Note 3 - Other Current Assets - Other Current Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995585 - Disclosure - Note 4 - Intangible Assets (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-4-intangible-assets-details-textual</Role>
      <ShortName>Note 4 - Intangible Assets (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-4-intangible-assets-tables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995586 - Disclosure - Note 4 - Intangible Assets - Schedule of Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-4-intangible-assets-schedule-of-intangible-assets-details</Role>
      <ShortName>Note 4 - Intangible Assets - Schedule of Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995587 - Disclosure - Note 5 - Accrued Liabilities - Schedule of Accrued Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-5-accrued-liabilities-schedule-of-accrued-liabilities-details</Role>
      <ShortName>Note 5 - Accrued Liabilities - Schedule of Accrued Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995588 - Disclosure - Note 6 - Convertible Promissory Note Due to Novartis (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-6-convertible-promissory-note-due-to-novartis-details-textual</Role>
      <ShortName>Note 6 - Convertible Promissory Note Due to Novartis (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-6-convertible-promissory-note-due-to-novartis-tables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995589 - Disclosure - Note 6 - Convertible Promissory Note Due to Novartis - Convertible Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-6-convertible-promissory-note-due-to-novartis-convertible-debt-details</Role>
      <ShortName>Note 6 - Convertible Promissory Note Due to Novartis - Convertible Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995590 - Disclosure - Note 7 - Promissory Notes Due to 3i, LP ("3i") (Details Textual)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-7-promissory-notes-due-to-3i-lp-3i-details-textual</Role>
      <ShortName>Note 7 - Promissory Notes Due to 3i, LP ("3i") (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-7-promissory-notes-due-to-3i-lp-3i-</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995591 - Disclosure - Note 8 - Preferred Stock (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-8-preferred-stock-details-textual</Role>
      <ShortName>Note 8 - Preferred Stock (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-8-preferred-stock-tables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995592 - Disclosure - Note 8 - Preferred Stock - Schedule of Valuation Inputs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-8-preferred-stock-schedule-of-valuation-inputs-details</Role>
      <ShortName>Note 8 - Preferred Stock - Schedule of Valuation Inputs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995593 - Disclosure - Note 9 - Warrant Liability (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-9-warrant-liability-details-textual</Role>
      <ShortName>Note 9 - Warrant Liability (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-9-warrant-liability-tables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995594 - Disclosure - Note 9 - Warrant Liability - Schedule of Derivative Liabilities and Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-9-warrant-liability-schedule-of-derivative-liabilities-and-fair-value-details</Role>
      <ShortName>Note 9 - Warrant Liability - Schedule of Derivative Liabilities and Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995595 - Disclosure - Note 10 - Stockholders' Equity (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-10-stockholders-equity-details-textual</Role>
      <ShortName>Note 10 - Stockholders' Equity (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-10-stockholders-equity</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995596 - Disclosure - Note 11 - Stock-based Compensation (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-11-stockbased-compensation-details-textual</Role>
      <ShortName>Note 11 - Stock-based Compensation (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-11-stockbased-compensation-tables</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995597 - Disclosure - Note 11 - Stock-based Compensation - Summary of Restricted Stock Unit Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-11-stockbased-compensation-summary-of-restricted-stock-unit-activity-details</Role>
      <ShortName>Note 11 - Stock-based Compensation - Summary of Restricted Stock Unit Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995598 - Disclosure - Note 11 - Stock-based Compensation - Schedule of Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-11-stockbased-compensation-schedule-of-stock-option-activity-details</Role>
      <ShortName>Note 11 - Stock-based Compensation - Schedule of Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>995599 - Disclosure - Note 11 - Stock-based Compensation - Stock-based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-11-stockbased-compensation-stockbased-compensation-expense-details</Role>
      <ShortName>Note 11 - Stock-based Compensation - Stock-based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>995600 - Disclosure - Note 12 - License and Development Agreements (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-12-license-and-development-agreements-details-textual</Role>
      <ShortName>Note 12 - License and Development Agreements (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-12-license-and-development-agreements-</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>995601 - Disclosure - Note 13 - Income Tax (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-13-income-tax-details-textual</Role>
      <ShortName>Note 13 - Income Tax (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-13-income-tax-tables</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>995602 - Disclosure - Note 13 - Income Tax - Income Tax Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-13-income-tax-income-tax-reconciliation-details</Role>
      <ShortName>Note 13 - Income Tax - Income Tax Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>995603 - Disclosure - Note 13 - Income Tax - Components of Net Loss Before Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-13-income-tax-components-of-net-loss-before-income-taxes-details</Role>
      <ShortName>Note 13 - Income Tax - Components of Net Loss Before Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>995604 - Disclosure - Note 13 - Income Tax - Schedule of Income Tax Expense (Benefit) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-13-income-tax-schedule-of-income-tax-expense-benefit-details</Role>
      <ShortName>Note 13 - Income Tax - Schedule of Income Tax Expense (Benefit) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>995605 - Disclosure - Note 13 - Income Tax - Schedule of Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-13-income-tax-schedule-of-deferred-tax-assets-and-liabilities-details</Role>
      <ShortName>Note 13 - Income Tax - Schedule of Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>995606 - Disclosure - Note 14 - Commitments and Contingencies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-14-commitments-and-contingencies-details-textual</Role>
      <ShortName>Note 14 - Commitments and Contingencies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-14-commitments-and-contingencies</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="allr20251231_10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>995607 - Disclosure - Note 15 - Subsequent Events (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20251231/role/statement-note-15-subsequent-events-details-textual</Role>
      <ShortName>Note 15 - Subsequent Events (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20251231/role/statement-note-15-subsequent-events</ParentRole>
      <Position>63</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>allr-20251231.xsd</File>
    <File>allr-20251231_cal.xml</File>
    <File>allr-20251231_def.xml</File>
    <File>allr-20251231_lab.xml</File>
    <File>allr-20251231_pre.xml</File>
    <File doctype="10-K" isDefinitelyFs="true" isUsgaap="true" original="allr20251231_10k.htm">allr20251231_10k.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="2">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="576">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="16">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="38">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="7">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
