<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>232</ContextCount>
  <ElementCount>256</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>56</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="ulbi20220630_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.ultralifecorporation.com/20220630/role/statement-document-and-entity-information</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>001 - Statement - Consolidated Balance Sheets (Current Period Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-consolidated-balance-sheets-current-period-unaudited</Role>
      <ShortName>Consolidated Balance Sheets (Current Period Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>003 - Statement - Consolidated Balance Sheets (Current Period Unaudited)-parentheticals (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-consolidated-balance-sheets-current-period-unauditedparentheticals-parentheticals</Role>
      <ShortName>Consolidated Balance Sheets (Current Period Unaudited)-parentheticals (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>004 - Statement - Consolidated Statements of (Loss) Income and Comprehensive (Loss) Income (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-consolidated-statements-of-loss-income-and-comprehensive-loss-income-unaudited</Role>
      <ShortName>Consolidated Statements of (Loss) Income and Comprehensive (Loss) Income (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>005 - Statement - Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-consolidated-statements-of-cash-flows-unaudited</Role>
      <ShortName>Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>006 - Statement - Consolidated Statements of Changes in Shareholders' Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-consolidated-statements-of-changes-in-shareholders-equity-unaudited</Role>
      <ShortName>Consolidated Statements of Changes in Shareholders' Equity (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>007 - Disclosure - Note 1 - Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-1-basis-of-presentation</Role>
      <ShortName>Note 1 - Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>008 - Disclosure - Note 2 - Acquisition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-2-acquisition</Role>
      <ShortName>Note 2 - Acquisition</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>009 - Disclosure - Note 3 - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-3-debt</Role>
      <ShortName>Note 3 - Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>010 - Disclosure - Note 4 - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-4-earnings-per-share</Role>
      <ShortName>Note 4 - Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>011 - Disclosure - Note 5 - Supplemental Balance Sheet Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information</Role>
      <ShortName>Note 5 - Supplemental Balance Sheet Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>012 - Disclosure - Note 6 - Stock-based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-6-stockbased-compensation</Role>
      <ShortName>Note 6 - Stock-based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>013 - Disclosure - Note 7 - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-7-income-taxes</Role>
      <ShortName>Note 7 - Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>014 - Disclosure - Note 8 - Operating Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-8-operating-leases</Role>
      <ShortName>Note 8 - Operating Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>015 - Disclosure - Note 9 - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-9-commitments-and-contingencies</Role>
      <ShortName>Note 9 - Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>016 - Disclosure - Note 10 - Revenue Recognition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-10-revenue-recognition</Role>
      <ShortName>Note 10 - Revenue Recognition</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>017 - Disclosure - Note 11 - Business Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-11-business-segment-information</Role>
      <ShortName>Note 11 - Business Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>018 - Disclosure - Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-significant-accounting-policies-policies</Role>
      <ShortName>Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>019 - Disclosure - Note 2 - Acquisition (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-2-acquisition-tables</Role>
      <ShortName>Note 2 - Acquisition (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-2-acquisition</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>020 - Disclosure - Note 5 - Supplemental Balance Sheet Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information-tables</Role>
      <ShortName>Note 5 - Supplemental Balance Sheet Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>021 - Disclosure - Note 6 - Stock-based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-6-stockbased-compensation-tables</Role>
      <ShortName>Note 6 - Stock-based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-6-stockbased-compensation</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>022 - Disclosure - Note 8 - Operating Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-8-operating-leases-tables</Role>
      <ShortName>Note 8 - Operating Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-8-operating-leases</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>023 - Disclosure - Note 9 - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-9-commitments-and-contingencies-tables</Role>
      <ShortName>Note 9 - Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-9-commitments-and-contingencies</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>024 - Disclosure - Note 11 - Business Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-11-business-segment-information-tables</Role>
      <ShortName>Note 11 - Business Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-11-business-segment-information</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>025 - Disclosure - Note 2 - Acquisition (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-2-acquisition-details-textual</Role>
      <ShortName>Note 2 - Acquisition (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-2-acquisition-tables</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>026 - Disclosure - Note 2 - Acquisition - Assets Acquired and Liabilities Assumed (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-2-acquisition-assets-acquired-and-liabilities-assumed-details</Role>
      <ShortName>Note 2 - Acquisition - Assets Acquired and Liabilities Assumed (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>027 - Disclosure - Note 2 - Acquisition - Estimated Fair Value and Annual Amortization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-2-acquisition-estimated-fair-value-and-annual-amortization-details</Role>
      <ShortName>Note 2 - Acquisition - Estimated Fair Value and Annual Amortization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>028 - Disclosure - Note 3 - Debt (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-3-debt-details-textual</Role>
      <ShortName>Note 3 - Debt (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-3-debt</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>029 - Disclosure - Note 4 - Earnings Per Share (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-4-earnings-per-share-details-textual</Role>
      <ShortName>Note 4 - Earnings Per Share (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-4-earnings-per-share</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>030 - Disclosure - Note 5 - Supplemental Balance Sheet Information (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information-details-textual</Role>
      <ShortName>Note 5 - Supplemental Balance Sheet Information (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information-tables</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>031 - Disclosure - Note 5 - Supplemental Balance Sheet Information - Cash and Restricted Cash (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information-cash-and-restricted-cash-details</Role>
      <ShortName>Note 5 - Supplemental Balance Sheet Information - Cash and Restricted Cash (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>032 - Disclosure - Note 5 - Supplemental Balance Sheet Information - Components of Inventory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information-components-of-inventory-details</Role>
      <ShortName>Note 5 - Supplemental Balance Sheet Information - Components of Inventory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>033 - Disclosure - Note 5 - Supplemental Balance Sheet Information - Components of Property, Plant and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information-components-of-property-plant-and-equipment-details</Role>
      <ShortName>Note 5 - Supplemental Balance Sheet Information - Components of Property, Plant and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>034 - Disclosure - Note 5 - Supplemental Balance Sheet Information - Summary of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information-summary-of-goodwill-details</Role>
      <ShortName>Note 5 - Supplemental Balance Sheet Information - Summary of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>035 - Disclosure - Note 5 - Supplemental Balance Sheet Information - Composition of Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information-composition-of-intangible-assets-details</Role>
      <ShortName>Note 5 - Supplemental Balance Sheet Information - Composition of Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>036 - Disclosure - Note 5 - Supplemental Balance Sheet Information - Amortization of Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-5-supplemental-balance-sheet-information-amortization-of-intangible-assets-details</Role>
      <ShortName>Note 5 - Supplemental Balance Sheet Information - Amortization of Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>037 - Disclosure - Note 6 - Stock-based Compensation (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-6-stockbased-compensation-details-textual</Role>
      <ShortName>Note 6 - Stock-based Compensation (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-6-stockbased-compensation-tables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>038 - Disclosure - Note 6 - Stock-based Compensation - Non-cash Stock Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-6-stockbased-compensation-noncash-stock-compensation-expense-details</Role>
      <ShortName>Note 6 - Stock-based Compensation - Non-cash Stock Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>039 - Disclosure - Note 6 - Stock-based Compensation - Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-6-stockbased-compensation-stock-option-activity-details</Role>
      <ShortName>Note 6 - Stock-based Compensation - Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>040 - Disclosure - Note 7 - Income Taxes (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-7-income-taxes-details-textual</Role>
      <ShortName>Note 7 - Income Taxes (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-7-income-taxes</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>041 - Disclosure - Note 8 - Operating Leases (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-8-operating-leases-details-textual</Role>
      <ShortName>Note 8 - Operating Leases (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-8-operating-leases-tables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>042 - Disclosure - Note 8 - Operating Leases - Lease Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-8-operating-leases-lease-cost-details</Role>
      <ShortName>Note 8 - Operating Leases - Lease Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>043 - Disclosure - Note 8 - Operating Leases - Supplement Cash Flow Information Related to Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-8-operating-leases-supplement-cash-flow-information-related-to-leases-details</Role>
      <ShortName>Note 8 - Operating Leases - Supplement Cash Flow Information Related to Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>044 - Disclosure - Note 8 - Operating Leases - Supplemental Balance Sheet Information Related to Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-8-operating-leases-supplemental-balance-sheet-information-related-to-leases-details</Role>
      <ShortName>Note 8 - Operating Leases - Supplemental Balance Sheet Information Related to Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>045 - Disclosure - Note 8 - Operating Leases - Future Minimum Lease Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-8-operating-leases-future-minimum-lease-payments-details</Role>
      <ShortName>Note 8 - Operating Leases - Future Minimum Lease Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>046 - Disclosure - Note 9 - Commitments and Contingencies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-9-commitments-and-contingencies-details-textual</Role>
      <ShortName>Note 9 - Commitments and Contingencies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-9-commitments-and-contingencies-tables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>047 - Disclosure - Note 9 - Commitments and Contingencies - Changes in Produce Warranty Liability (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-9-commitments-and-contingencies-changes-in-produce-warranty-liability-details</Role>
      <ShortName>Note 9 - Commitments and Contingencies - Changes in Produce Warranty Liability (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>048 - Disclosure - Note 11 - Business Segment Information (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-11-business-segment-information-details-textual</Role>
      <ShortName>Note 11 - Business Segment Information (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ultralifecorporation.com/20220630/role/statement-note-11-business-segment-information-tables</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>049 - Disclosure - Note 11 - Business Segment Information - Segment Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-11-business-segment-information-segment-activity-details</Role>
      <ShortName>Note 11 - Business Segment Information - Segment Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>050 - Disclosure - Note 11 - Business Segment Information - Revenue by Business Segment Sector (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-11-business-segment-information-revenue-by-business-segment-sector-details</Role>
      <ShortName>Note 11 - Business Segment Information - Revenue by Business Segment Sector (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="ulbi20220630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>051 - Disclosure - Note 11 - Business Segment Information - Domestic and International Revenue by Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ultralifecorporation.com/20220630/role/statement-note-11-business-segment-information-domestic-and-international-revenue-by-segment-details</Role>
      <ShortName>Note 11 - Business Segment Information - Domestic and International Revenue by Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-Q" original="ulbi20220630_10q.htm">ulbi20220630_10q.htm</File>
    <File>ex_397800.htm</File>
    <File>ex_397801.htm</File>
    <File>ex_397802.htm</File>
    <File>ulbi-20220630.xsd</File>
    <File>ulbi-20220630_cal.xml</File>
    <File>ulbi-20220630_def.xml</File>
    <File>ulbi-20220630_lab.xml</File>
    <File>ulbi-20220630_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="773">http://fasb.org/us-gaap/2022</BaseTaxonomy>
    <BaseTaxonomy items="29">http://xbrl.sec.gov/dei/2022</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
