<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>130</ContextCount>
  <ElementCount>208</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>37</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="allr20250630_10q.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/20250630/role/statement-document-and-entity-information</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>001 - Statement - Condensed Consolidated Balance Sheets (Current Period Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-condensed-consolidated-balance-sheets-current-period-unaudited</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Current Period Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>002 - Statement - Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-condensed-consolidated-balance-sheets-current-period-unaudited-parentheticals</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>003 - Statement - Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-condensed-consolidated-statements-of-operations-and-comprehensive-loss-unaudited</Role>
      <ShortName>Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>004 - Statement - Condensed Consolidated Statements of Changes in Redeemable Convertible Stockholders' Equity (Deficit) (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-condensed-consolidated-statements-of-changes-in-redeemable-convertible-stockholders-equity-deficit-unaudited</Role>
      <ShortName>Condensed Consolidated Statements of Changes in Redeemable Convertible Stockholders' Equity (Deficit) (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>005 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-condensed-consolidated-statements-of-cash-flows-unaudited</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>006 - Disclosure - Note 1 - Organization, Principal Activities and Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-1-organization-principal-activities-and-basis-of-presentation</Role>
      <ShortName>Note 1 - Organization, Principal Activities and Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>007 - Disclosure - Note 2 - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-2-summary-of-significant-accounting-policies</Role>
      <ShortName>Note 2 - Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>008 - Disclosure - Note 3 - Accrued Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-3-accrued-liabilities-</Role>
      <ShortName>Note 3 - Accrued Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>009 - Disclosure - Note 4 - Convertible Promissory Note Due to Novartis</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-4-convertible-promissory-note-due-to-novartis</Role>
      <ShortName>Note 4 - Convertible Promissory Note Due to Novartis</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>010 - Disclosure - Note 5 - Warrant liability</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-5-warrant-liability</Role>
      <ShortName>Note 5 - Warrant liability</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>011 - Disclosure - Note 6 - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-6-stockholders-equity</Role>
      <ShortName>Note 6 - Stockholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>012 - Disclosure - Note 7 - License and Development Agreements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-7-license-and-development-agreements-</Role>
      <ShortName>Note 7 - License and Development Agreements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>013 - Disclosure - Note 8 - Loss Per Share of Common Stock</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-8-loss-per-share-of-common-stock-</Role>
      <ShortName>Note 8 - Loss Per Share of Common Stock</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>014 - Disclosure - Note 9 - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-9-commitments-and-contingencies</Role>
      <ShortName>Note 9 - Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>015 - Disclosure - Note 10 - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-10-subsequent-events-</Role>
      <ShortName>Note 10 - Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.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>17</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995462 - Disclosure - Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-significant-accounting-policies-policies</Role>
      <ShortName>Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-2-summary-of-significant-accounting-policies</ParentRole>
      <Position>18</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995463 - Disclosure - Note 2 - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/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/20250630/role/statement-note-2-summary-of-significant-accounting-policies</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995464 - Disclosure - Note 3 - Accrued Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-3-accrued-liabilities-tables</Role>
      <ShortName>Note 3 - Accrued Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-3-accrued-liabilities-</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995465 - Disclosure - Note 5 - Warrant liability (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-5-warrant-liability-tables</Role>
      <ShortName>Note 5 - Warrant liability (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-5-warrant-liability</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995466 - Disclosure - Note 6 - Stockholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-6-stockholders-equity-tables</Role>
      <ShortName>Note 6 - Stockholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-6-stockholders-equity</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995467 - Disclosure - Note 8 - Loss Per Share of Common Stock (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-8-loss-per-share-of-common-stock-tables</Role>
      <ShortName>Note 8 - Loss Per Share of Common Stock (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-8-loss-per-share-of-common-stock-</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995468 - Disclosure - Note 1 - Organization, Principal Activities and Basis of Presentation (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-1-organization-principal-activities-and-basis-of-presentation-details-textual</Role>
      <ShortName>Note 1 - Organization, Principal Activities and Basis of Presentation (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-1-organization-principal-activities-and-basis-of-presentation</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995469 - Disclosure - Note 2 - Summary of Significant Accounting Policies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/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/20250630/role/statement-note-2-summary-of-significant-accounting-policies-tables</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995470 - Disclosure - Note 2 - Summary of Significant Accounting Policies - Estimated Useful Life of Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/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>26</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995471 - Disclosure - Note 3 - Accrued Liabilities - Schedule of Accrued Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-3-accrued-liabilities-schedule-of-accrued-liabilities-details</Role>
      <ShortName>Note 3 - Accrued Liabilities - Schedule of Accrued Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995472 - Disclosure - Note 4 - Convertible Promissory Note Due to Novartis (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-4-convertible-promissory-note-due-to-novartis-details-textual</Role>
      <ShortName>Note 4 - Convertible Promissory Note Due to Novartis (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-4-convertible-promissory-note-due-to-novartis</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995473 - Disclosure - Note 5 - Warrant liability (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-5-warrant-liability-details-textual</Role>
      <ShortName>Note 5 - Warrant liability (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-5-warrant-liability-tables</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995474 - Disclosure - Note 5 - Warrant Liability - Schedule of Derivative Liabilities and Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-5-warrant-liability-schedule-of-derivative-liabilities-and-fair-value-details</Role>
      <ShortName>Note 5 - Warrant Liability - Schedule of Derivative Liabilities and Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995475 - Disclosure - Note 5 - Warrant Liability - Valuation Techniques (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-5-warrant-liability-valuation-techniques-details</Role>
      <ShortName>Note 5 - Warrant Liability - Valuation Techniques (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995476 - Disclosure - Note 6 - Stockholders' Equity (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-6-stockholders-equity-details-textual</Role>
      <ShortName>Note 6 - Stockholders' Equity (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-6-stockholders-equity-tables</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995477 - Disclosure - Note 6 - Stockholders' Equity - Stock-based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-6-stockholders-equity-stockbased-compensation-expense-details</Role>
      <ShortName>Note 6 - Stockholders' Equity - Stock-based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995478 - Disclosure - Note 6 - Stockholders' Equity - Summary of Restricted Stock Unit Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-6-stockholders-equity-summary-of-restricted-stock-unit-activity-details</Role>
      <ShortName>Note 6 - Stockholders' Equity - Summary of Restricted Stock Unit Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995479 - Disclosure - Note 6 - Stockholders' Equity - Summary of Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-6-stockholders-equity-summary-of-stock-option-activity-details</Role>
      <ShortName>Note 6 - Stockholders' Equity - Summary of Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995480 - Disclosure - Note 6 - Stockholders' Equity - Share-based Compensation Valuation Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-6-stockholders-equity-sharebased-compensation-valuation-assumptions-details</Role>
      <ShortName>Note 6 - Stockholders' Equity - Share-based Compensation Valuation Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995481 - Disclosure - Note 7 - License and Development Agreements (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-7-license-and-development-agreements-details-textual</Role>
      <ShortName>Note 7 - License and Development Agreements (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-7-license-and-development-agreements-</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995482 - Disclosure - Note 8 - Loss Per Share of Common Stock - Schedule of Antidilutive Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-8-loss-per-share-of-common-stock-schedule-of-antidilutive-securities-details</Role>
      <ShortName>Note 8 - Loss Per Share of Common Stock - Schedule of Antidilutive Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="allr20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995483 - Disclosure - Note 9 - Commitments and Contingencies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://allarity.com/20250630/role/statement-note-9-commitments-and-contingencies-details-textual</Role>
      <ShortName>Note 9 - Commitments and Contingencies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://allarity.com/20250630/role/statement-note-9-commitments-and-contingencies</ParentRole>
      <Position>39</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-20250630.xsd</File>
    <File>allr-20250630_cal.xml</File>
    <File>allr-20250630_def.xml</File>
    <File>allr-20250630_lab.xml</File>
    <File>allr-20250630_pre.xml</File>
    <File doctype="10-Q" isDefinitelyFs="true" isUsgaap="true" original="allr20250630_10q.htm">allr20250630_10q.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="1">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="501">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="30">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="5">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
