<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>166</ContextCount>
  <ElementCount>237</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>52</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="lglg20260331_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://www.lglgroup.com/20260331/role/statement-document-and-entity-information</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="lglg20260331_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://www.lglgroup.com/20260331/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="lglg20260331_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://www.lglgroup.com/20260331/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="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>003 - Statement - Condensed Consolidated Statements of Operations (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-condensed-consolidated-statements-of-operations-unaudited</Role>
      <ShortName>Condensed Consolidated Statements of Operations (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>004 - Statement - Condensed Consolidated Statements of Stockholders' Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-condensed-consolidated-statements-of-stockholders-equity-unaudited</Role>
      <ShortName>Condensed Consolidated Statements of Stockholders' Equity (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="lglg20260331_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://www.lglgroup.com/20260331/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="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>006 - Disclosure - Note 1 - Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-1-basis-of-presentation-</Role>
      <ShortName>Note 1 - Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="lglg20260331_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://www.lglgroup.com/20260331/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="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>008 - Disclosure - Note 3 - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-3-segment-information</Role>
      <ShortName>Note 3 - Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>009 - Disclosure - Note 4 - Investments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-4-investments</Role>
      <ShortName>Note 4 - Investments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>010 - Disclosure - Note 5 - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-5-fair-value-measurements</Role>
      <ShortName>Note 5 - Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>011 - Disclosure - Note 6 - Variable Interest Entities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-6-variable-interest-entities</Role>
      <ShortName>Note 6 - Variable Interest Entities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>012 - Disclosure - Note 7 - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-7-related-party-transactions</Role>
      <ShortName>Note 7 - Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>013 - Disclosure - Note 8 - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-8-income-taxes</Role>
      <ShortName>Note 8 - Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>014 - Disclosure - Note 9 - Stock-based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-9-stockbased-compensation</Role>
      <ShortName>Note 9 - Stock-based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>015 - Disclosure - Note 10 - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-10-stockholders-equity</Role>
      <ShortName>Note 10 - Stockholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>016 - Disclosure - Note 11 - Earnings Per Share ("EPS")</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-11-earnings-per-share-eps</Role>
      <ShortName>Note 11 - Earnings Per Share ("EPS")</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>017 - Disclosure - Note 12 - Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-12-contingencies</Role>
      <ShortName>Note 12 - Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>018 - Disclosure - Note 13 - Other Financial Statement Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-13-other-financial-statement-information</Role>
      <ShortName>Note 13 - Other Financial Statement Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>019 - Disclosure - Note 14 - Domestic and Foreign Revenues</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-14-domestic-and-foreign-revenues</Role>
      <ShortName>Note 14 - Domestic and Foreign Revenues</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>020 - Disclosure - Note 15 - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-15-subsequent-events</Role>
      <ShortName>Note 15 - Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.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>22</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995467 - Disclosure - Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-significant-accounting-policies-policies</Role>
      <ShortName>Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-2-summary-of-significant-accounting-policies</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995468 - Disclosure - Note 3 - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-3-segment-information-tables</Role>
      <ShortName>Note 3 - Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-3-segment-information</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995469 - Disclosure - Note 4 - Investments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-4-investments-tables</Role>
      <ShortName>Note 4 - Investments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-4-investments</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995470 - Disclosure - Note 5 - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-5-fair-value-measurements-tables</Role>
      <ShortName>Note 5 - Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-5-fair-value-measurements</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995471 - Disclosure - Note 6 - Variable Interest Entities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-6-variable-interest-entities-tables</Role>
      <ShortName>Note 6 - Variable Interest Entities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-6-variable-interest-entities</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995472 - Disclosure - Note 7 - Related Party Transactions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-7-related-party-transactions-tables</Role>
      <ShortName>Note 7 - Related Party Transactions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-7-related-party-transactions</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995473 - Disclosure - Note 9 - Stock-based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-9-stockbased-compensation-tables</Role>
      <ShortName>Note 9 - Stock-based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-9-stockbased-compensation</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995474 - Disclosure - Note 10 - Stockholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-10-stockholders-equity-tables</Role>
      <ShortName>Note 10 - Stockholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-10-stockholders-equity</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995475 - Disclosure - Note 11 - Earnings Per Share ("EPS") (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-11-earnings-per-share-eps-tables</Role>
      <ShortName>Note 11 - Earnings Per Share ("EPS") (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-11-earnings-per-share-eps</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995476 - Disclosure - Note 13 - Other Financial Statement Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-13-other-financial-statement-information-tables</Role>
      <ShortName>Note 13 - Other Financial Statement Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-13-other-financial-statement-information</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995477 - Disclosure - Note 14 - Domestic and Foreign Revenues (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-14-domestic-and-foreign-revenues-tables</Role>
      <ShortName>Note 14 - Domestic and Foreign Revenues (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-14-domestic-and-foreign-revenues</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995478 - Disclosure - Note 3 - Segment Information (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-3-segment-information-details-textual</Role>
      <ShortName>Note 3 - Segment Information (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-3-segment-information-tables</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995479 - Disclosure - Note 3 - Segment Information - Schedule of Segment Reporting Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-3-segment-information-schedule-of-segment-reporting-information-details</Role>
      <ShortName>Note 3 - Segment Information - Schedule of Segment Reporting Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995480 - Disclosure - Note 3 - Segment Information - Schedule of Other Segment Disclosures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-3-segment-information-schedule-of-other-segment-disclosures-details</Role>
      <ShortName>Note 3 - Segment Information - Schedule of Other Segment Disclosures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995481 - Disclosure - Note 3 - Segment Information - Assets and Capital Expenditures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-3-segment-information-assets-and-capital-expenditures-details</Role>
      <ShortName>Note 3 - Segment Information - Assets and Capital Expenditures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995482 - Disclosure - Note 4 - Investments - Details of Marketable Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-4-investments-details-of-marketable-securities-details</Role>
      <ShortName>Note 4 - Investments - Details of Marketable Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995483 - Disclosure - Note 4 - Investments - Net Investment Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-4-investments-net-investment-income-details</Role>
      <ShortName>Note 4 - Investments - Net Investment Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995484 - Disclosure - Note 4 - Investments - Net Gain (Losses) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-4-investments-net-gain-losses-details</Role>
      <ShortName>Note 4 - Investments - Net Gain (Losses) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995485 - Disclosure - Note 5 - Fair Value Measurements (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-5-fair-value-measurements-details-textual</Role>
      <ShortName>Note 5 - Fair Value Measurements (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-5-fair-value-measurements-tables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995486 - Disclosure - Note 5 - Fair Value Measurements - Assets Measured at Fair Value on Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-5-fair-value-measurements-assets-measured-at-fair-value-on-recurring-basis-details</Role>
      <ShortName>Note 5 - Fair Value Measurements - Assets Measured at Fair Value on Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995487 - Disclosure - Note 6 - Variable Interest Entities (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-6-variable-interest-entities-details-textual</Role>
      <ShortName>Note 6 - Variable Interest Entities (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-6-variable-interest-entities-tables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995488 - Disclosure - Note 6 - Variable Interest Entities - VIEs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-6-variable-interest-entities-vies-details</Role>
      <ShortName>Note 6 - Variable Interest Entities - VIEs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-6-variable-interest-entities-tables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995489 - Disclosure - Note 7 - Related Party Transactions (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-7-related-party-transactions-details-textual</Role>
      <ShortName>Note 7 - Related Party Transactions (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-7-related-party-transactions-tables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995490 - Disclosure - Note 7 - Related Party Transactions - Transactions With Related Parties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-7-related-party-transactions-transactions-with-related-parties-details</Role>
      <ShortName>Note 7 - Related Party Transactions - Transactions With Related Parties (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995491 - Disclosure - Note 8 - Income Taxes (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-8-income-taxes-details-textual</Role>
      <ShortName>Note 8 - Income Taxes (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-8-income-taxes</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995492 - Disclosure - Note 9 - Stock-based Compensation (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-9-stockbased-compensation-details-textual</Role>
      <ShortName>Note 9 - Stock-based Compensation (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-9-stockbased-compensation-tables</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995493 - Disclosure - Note 9 - Stock-based Compensation - Stock-based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-9-stockbased-compensation-stockbased-compensation-expense-details</Role>
      <ShortName>Note 9 - Stock-based Compensation - Stock-based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995494 - Disclosure - Note 9 - Stock-based Compensation - Restricted Stock Awards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-9-stockbased-compensation-restricted-stock-awards-details</Role>
      <ShortName>Note 9 - Stock-based Compensation - Restricted Stock Awards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995495 - Disclosure - Note 9 - Stock-Based Compensation - Valuation Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-9-stockbased-compensation-valuation-assumptions-details</Role>
      <ShortName>Note 9 - Stock-Based Compensation - Valuation Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995496 - Disclosure - Note 9 - Stock-Based Compensation - Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-9-stockbased-compensation-stock-option-activity-details</Role>
      <ShortName>Note 9 - Stock-Based Compensation - Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995497 - Disclosure - Note 10 - Stockholders' Equity (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-10-stockholders-equity-details-textual</Role>
      <ShortName>Note 10 - Stockholders' Equity (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-10-stockholders-equity-tables</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995498 - Disclosure - Note 10 - Stockholders' Equity - Rollforward of Outstanding Shares (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-10-stockholders-equity-rollforward-of-outstanding-shares-details</Role>
      <ShortName>Note 10 - Stockholders' Equity - Rollforward of Outstanding Shares (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>995499 - Disclosure - Note 11 - Earnings Per Share ("EPS") (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-11-earnings-per-share-eps-details-textual</Role>
      <ShortName>Note 11 - Earnings Per Share ("EPS") (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-11-earnings-per-share-eps-tables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>995500 - Disclosure - Note 11 - Earnings Per Share ("EPS") - Reconciliation of Basic to Diluted Weighted Average Shares Outstanding (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-11-earnings-per-share-eps-reconciliation-of-basic-to-diluted-weighted-average-shares-outstanding-details</Role>
      <ShortName>Note 11 - Earnings Per Share ("EPS") - Reconciliation of Basic to Diluted Weighted Average Shares Outstanding (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lglgroup.com/20260331/role/statement-note-11-earnings-per-share-eps-tables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>995501 - Disclosure - Note 13 - Other Financial Statement Information - Schedule of Components of Inventory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-13-other-financial-statement-information-schedule-of-components-of-inventory-details</Role>
      <ShortName>Note 13 - Other Financial Statement Information - Schedule of Components of Inventory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>995502 - Disclosure - Note 13 - Other Financial Statement Information - Intangible Assets, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-13-other-financial-statement-information-intangible-assets-net-details</Role>
      <ShortName>Note 13 - Other Financial Statement Information - Intangible Assets, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="lglg20260331_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>995503 - Disclosure - Note 14 - Domestic and Foreign Revenues - Schedule of Revenues (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lglgroup.com/20260331/role/statement-note-14-domestic-and-foreign-revenues-schedule-of-revenues-details</Role>
      <ShortName>Note 14 - Domestic and Foreign Revenues - Schedule of Revenues (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>lgl-20260331.xsd</File>
    <File>lgl-20260331_cal.xml</File>
    <File>lgl-20260331_def.xml</File>
    <File>lgl-20260331_lab.xml</File>
    <File>lgl-20260331_pre.xml</File>
    <File doctype="10-Q" isDefinitelyFs="true" isUsgaap="true" original="lglg20260331_10q.htm">lglg20260331_10q.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>logo.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="2">http://fasb.org/srt/2026</BaseTaxonomy>
    <BaseTaxonomy items="651">http://fasb.org/us-gaap/2026</BaseTaxonomy>
    <BaseTaxonomy items="29">http://xbrl.sec.gov/dei/2026</BaseTaxonomy>
    <BaseTaxonomy items="5">http://xbrl.sec.gov/ecd/2026</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
