<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>102</ContextCount>
  <ElementCount>292</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>48</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-document-and-entity-information</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>001 - Statement - Statements of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-statements-of-income-</Role>
      <ShortName>Statements of Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>002 - Statement - Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-balance-sheets-</Role>
      <ShortName>Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>003 - Statement - Balance Sheets (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-balance-sheets-parentheticals</Role>
      <ShortName>Balance Sheets (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>004 - Statement - Statements of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-statements-of-stockholders-equity-</Role>
      <ShortName>Statements of Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>005 - Statement - Statements of Stockholders' Equity (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-statements-of-stockholders-equity-parentheticals</Role>
      <ShortName>Statements of Stockholders' Equity (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>006 - Statement - Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-statements-of-cash-flows-</Role>
      <ShortName>Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>007 - Disclosure - Note A - Nature of Business and Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-a-nature-of-business-and-summary-of-significant-accounting-policies-</Role>
      <ShortName>Note A - Nature of Business and Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>008 - Disclosure - Note B - Marketable Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-b-marketable-securities</Role>
      <ShortName>Note B - Marketable Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>009 - Disclosure - Note C - Inventories</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-c-inventories</Role>
      <ShortName>Note C - Inventories</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>010 - Disclosure - Note D - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-d-income-taxes</Role>
      <ShortName>Note D - Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>011 - Disclosure - Note E - Benefit Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-e-benefit-plans</Role>
      <ShortName>Note E - Benefit Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>012 - Disclosure - Note F - Geographic and Other Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-f-geographic-and-other-information</Role>
      <ShortName>Note F - Geographic and Other Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>013 - Disclosure - Note G - Accrued Expenses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-g-accrued-expenses</Role>
      <ShortName>Note G - Accrued Expenses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>014 - Disclosure - Note H - Supplemental Disclosures of Cash Flow Information and Non-cash Investing and Financing Activities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-h-supplemental-disclosures-of-cash-flow-information-and-noncash-investing-and-financing-activities</Role>
      <ShortName>Note H - Supplemental Disclosures of Cash Flow Information and Non-cash Investing and Financing Activities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>015 - Disclosure - Note I - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-i-related-party-transactions</Role>
      <ShortName>Note I - Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>016 - Disclosure - Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-significant-accounting-policies-policies</Role>
      <ShortName>Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-a-nature-of-business-and-summary-of-significant-accounting-policies-</ParentRole>
      <Position>17</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>017 - Disclosure - Note A - Nature of Business and Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-a-nature-of-business-and-summary-of-significant-accounting-policies-tables</Role>
      <ShortName>Note A - Nature of Business and Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-a-nature-of-business-and-summary-of-significant-accounting-policies-</ParentRole>
      <Position>18</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>018 - Disclosure - Note B - Marketable Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-b-marketable-securities-tables</Role>
      <ShortName>Note B - Marketable Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-b-marketable-securities</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>019 - Disclosure - Note C - Inventories (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-c-inventories-tables</Role>
      <ShortName>Note C - Inventories (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-c-inventories</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>020 - Disclosure - Note D - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-d-income-taxes-tables</Role>
      <ShortName>Note D - Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-d-income-taxes</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>021 - Disclosure - Note F - Geographic and Other Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-f-geographic-and-other-information-tables</Role>
      <ShortName>Note F - Geographic and Other Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-f-geographic-and-other-information</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>022 - Disclosure - Note G - Accrued Expenses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-g-accrued-expenses-tables</Role>
      <ShortName>Note G - Accrued Expenses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-g-accrued-expenses</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>023 - Disclosure - Note A - Nature of Business and Summary of Significant Accounting Policies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-a-nature-of-business-and-summary-of-significant-accounting-policies-details-textual</Role>
      <ShortName>Note A - Nature of Business and Summary of Significant Accounting Policies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-a-nature-of-business-and-summary-of-significant-accounting-policies-tables</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>024 - Disclosure - Note A - Nature of Business and Summary of Significant Accounting Policies - Disaggregated Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-a-nature-of-business-and-summary-of-significant-accounting-policies-disaggregated-revenue-details</Role>
      <ShortName>Note A - Nature of Business and Summary of Significant Accounting Policies - Disaggregated Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>025 - Disclosure - Note A - Nature of Business and Summary of Significant Accounting Policies - Revenue by Geographic Region (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-a-nature-of-business-and-summary-of-significant-accounting-policies-revenue-by-geographic-region-details</Role>
      <ShortName>Note A - Nature of Business and Summary of Significant Accounting Policies - Revenue by Geographic Region (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>026 - Disclosure - Note A - Nature of Business and Summary of Significant Accounting Policies - Property, Plant, and Equipment Useful Lives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-a-nature-of-business-and-summary-of-significant-accounting-policies-property-plant-and-equipment-useful-lives-details</Role>
      <ShortName>Note A - Nature of Business and Summary of Significant Accounting Policies - Property, Plant, and Equipment Useful Lives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>027 - Disclosure - Note B - Marketable Securities (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-b-marketable-securities-details-textual</Role>
      <ShortName>Note B - Marketable Securities (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-b-marketable-securities-tables</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>028 - Disclosure - Note B - Marketable Securities - Net Gains and Losses on Marketable Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-b-marketable-securities-net-gains-and-losses-on-marketable-securities-details</Role>
      <ShortName>Note B - Marketable Securities - Net Gains and Losses on Marketable Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>029 - Disclosure - Note B - Marketable Securities - Summary of Investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-b-marketable-securities-summary-of-investments-details</Role>
      <ShortName>Note B - Marketable Securities - Summary of Investments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>030 - Disclosure - Note C - Inventories (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-c-inventories-details-textual</Role>
      <ShortName>Note C - Inventories (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-c-inventories-tables</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>031 - Disclosure - Note C - Inventories - Summary of Inventories (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-c-inventories-summary-of-inventories-details</Role>
      <ShortName>Note C - Inventories - Summary of Inventories (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>032 - Disclosure - Note D - Income Taxes - Provision for Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-d-income-taxes-provision-for-income-taxes-details</Role>
      <ShortName>Note D - Income Taxes - Provision for Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>033 - Disclosure - Note D - Income Taxes - Reconciliation of the Effective Income Tax Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-d-income-taxes-reconciliation-of-the-effective-income-tax-rate-details</Role>
      <ShortName>Note D - Income Taxes - Reconciliation of the Effective Income Tax Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>034 - Disclosure - Note D - Income Taxes - Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-d-income-taxes-deferred-tax-assets-and-liabilities-details</Role>
      <ShortName>Note D - Income Taxes - Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>035 - Disclosure - Note E - Benefit Plans (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-e-benefit-plans-details-textual</Role>
      <ShortName>Note E - Benefit Plans (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-e-benefit-plans</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>036 - Disclosure - Note F - Geographic and Other Information (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-f-geographic-and-other-information-details-textual</Role>
      <ShortName>Note F - Geographic and Other Information (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-f-geographic-and-other-information-tables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>037 - Disclosure - Note F - Geographic and Other Information - Net Sales (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-f-geographic-and-other-information-net-sales-details</Role>
      <ShortName>Note F - Geographic and Other Information - Net Sales (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>038 - Disclosure - Note F - Geographic and Other Information - Geographic Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-f-geographic-and-other-information-geographic-information-details</Role>
      <ShortName>Note F - Geographic and Other Information - Geographic Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>039 - Disclosure - Note F - Geographic and Other Information - Sales to Major Customers (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-f-geographic-and-other-information-sales-to-major-customers-details</Role>
      <ShortName>Note F - Geographic and Other Information - Sales to Major Customers (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>040 - Disclosure - Note G - Accrued Expenses - Summary of Accrued Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-g-accrued-expenses-summary-of-accrued-expenses-details</Role>
      <ShortName>Note G - Accrued Expenses - Summary of Accrued Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>041 - Disclosure - Note H - Supplemental Disclosures of Cash Flow Information and Non-cash Investing and Financing Activities (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-h-supplemental-disclosures-of-cash-flow-information-and-noncash-investing-and-financing-activities-details-textual</Role>
      <ShortName>Note H - Supplemental Disclosures of Cash Flow Information and Non-cash Investing and Financing Activities (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-h-supplemental-disclosures-of-cash-flow-information-and-noncash-investing-and-financing-activities</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="ug-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>042 - Disclosure - Note I - Related Party Transactions (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://u-g.com/20191231/role/statement-note-i-related-party-transactions-details-textual</Role>
      <ShortName>Note I - Related Party Transactions (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://u-g.com/20191231/role/statement-note-i-related-party-transactions</ParentRole>
      <Position>43</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>ug-20191231.xml</File>
    <File>ug-20191231.xsd</File>
    <File>ug-20191231_cal.xml</File>
    <File>ug-20191231_def.xml</File>
    <File>ug-20191231_lab.xml</File>
    <File>ug-20191231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/country/2017-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2019-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
