<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>219</ContextCount>
  <ElementCount>407</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>74</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001501 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ConsolidatedStatementsOfOperations</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1002501 - Statement - Consolidated Statements of Operations (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ConsolidatedStatementsOfOperationsParenthetical</Role>
      <ShortName>Consolidated Statements of Operations (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005000 - Statement - Consolidated Statements of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ConsolidatedStatementsOfStockholdersEquity</Role>
      <ShortName>Consolidated Statements of Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1006000 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/BasisOfPresentation</Role>
      <ShortName>Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - Leases (Notes)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://westell.com/role/LeasesNotes</Role>
      <ShortName>Leases (Notes)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Revenue Recognition (Notes)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://westell.com/role/RevenueRecognitionNotes</Role>
      <ShortName>Revenue Recognition (Notes)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IntangibleAssets</Role>
      <ShortName>Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Product Warranties</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ProductWarranties</Role>
      <ShortName>Product Warranties</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - Capital Stock and Stock Restrictions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/CapitalStockAndStockRestrictions</Role>
      <ShortName>Capital Stock and Stock Restrictions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/StockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2118100 - Disclosure - Restructuring Charge</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/RestructuringCharge</Role>
      <ShortName>Restructuring Charge</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2120100 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2121100 - Disclosure - Variable Interest Entity Variable Interest Entity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/VariableInterestEntityVariableInterestEntity</Role>
      <ShortName>Variable Interest Entity Variable Interest Entity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2123100 - Disclosure - Benefit Plans Benefit Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/BenefitPlansBenefitPlans</Role>
      <ShortName>Benefit Plans Benefit Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2125100 - Disclosure - Subsequent Events (Notes)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://westell.com/role/SubsequentEventsNotes</Role>
      <ShortName>Subsequent Events (Notes)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2126100 - Schedule - Schedule II - Valuation and Qualifying Accounts Schedule II - Valuation and Qualifying Accounts</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ScheduleIiValuationAndQualifyingAccountsScheduleIiValuationAndQualifyingAccounts</Role>
      <ShortName>Schedule II - Valuation and Qualifying Accounts Schedule II - Valuation and Qualifying Accounts</ShortName>
      <MenuCategory>Uncategorized</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2204201 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2304302 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2305301 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/LeasesNotes</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Revenue Recognition (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/RevenueRecognitionTables</Role>
      <ShortName>Revenue Recognition (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/RevenueRecognitionNotes</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/IncomeTaxes</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IntangibleAssetsTables</Role>
      <ShortName>Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/IntangibleAssets</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - Product Warranties (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ProductWarrantiesTables</Role>
      <ShortName>Product Warranties (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/ProductWarranties</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2312301 - Disclosure - Capital Stock and Stock Restrictions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/CapitalStockAndStockRestrictionsTables</Role>
      <ShortName>Capital Stock and Stock Restrictions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/CapitalStockAndStockRestrictions</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2313301 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/StockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/StockBasedCompensation</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2316301 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/SegmentInformation</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2318301 - Disclosure - Restructuring Charge (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/RestructuringChargeTables</Role>
      <ShortName>Restructuring Charge (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/RestructuringCharge</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2320301 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://westell.com/role/FairValueMeasurements</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2401401 - Disclosure - Basis of Presentation (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/BasisOfPresentationDetailsTextual</Role>
      <ShortName>Basis of Presentation (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/BasisOfPresentation</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2404403 - Disclosure - Summary of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/SummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2404404 - Disclosure - Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SummaryOfSignificantAccountingPoliciesSummaryOfSignificantAccountingPoliciesDetails2</Role>
      <ShortName>Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2404405 - Disclosure - Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SummaryOfSignificantAccountingPoliciesSummaryOfSignificantAccountingPoliciesDetails3</Role>
      <ShortName>Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 3)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2404406 - Disclosure - Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 4)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SummaryOfSignificantAccountingPoliciesSummaryOfSignificantAccountingPoliciesDetails4</Role>
      <ShortName>Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 4)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2404407 - Disclosure - Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 5)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SummaryOfSignificantAccountingPoliciesSummaryOfSignificantAccountingPoliciesDetails5</Role>
      <ShortName>Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 5)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2404408 - Disclosure - Summary of Significant Accounting Policies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SummaryOfSignificantAccountingPoliciesDetailsTextual</Role>
      <ShortName>Summary of Significant Accounting Policies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/SummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/LeasesDetails</Role>
      <ShortName>Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/LeasesTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2405403 - Disclosure - Leases (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/LeasesDetails2</Role>
      <ShortName>Leases (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/LeasesTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2405404 - Disclosure - Leases (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/LeasesDetails3</Role>
      <ShortName>Leases (Details 3)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/LeasesTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2405405 - Disclosure - Leases (Details textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/LeasesDetailsTextual</Role>
      <ShortName>Leases (Details textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/LeasesTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - Revenue Recognition (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/RevenueRecognitionDetails</Role>
      <ShortName>Revenue Recognition (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/RevenueRecognitionTables</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2406403 - Disclosure - Revenue Recognition (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/RevenueRecognitionDetails2</Role>
      <ShortName>Revenue Recognition (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/RevenueRecognitionTables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2406404 - Disclosure - Revenue Recognition (Details textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/RevenueRecognitionDetailsTextual</Role>
      <ShortName>Revenue Recognition (Details textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/RevenueRecognitionTables</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/IncomeTaxesTables</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Income Taxes (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IncomeTaxesDetails1</Role>
      <ShortName>Income Taxes (Details 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/IncomeTaxesTables</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2407404 - Disclosure - Income Taxes (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IncomeTaxesDetails2</Role>
      <ShortName>Income Taxes (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/IncomeTaxesTables</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2407405 - Disclosure - Income Taxes (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IncomeTaxesDetails3</Role>
      <ShortName>Income Taxes (Details 3)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/IncomeTaxesTables</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2407406 - Disclosure - Income Taxes (Details 4)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IncomeTaxesDetails4</Role>
      <ShortName>Income Taxes (Details 4)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/IncomeTaxesTables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2407407 - Disclosure - Income Taxes (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IncomeTaxesDetailsTextual</Role>
      <ShortName>Income Taxes (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/IncomeTaxesTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IntangibleAssetsDetails</Role>
      <ShortName>Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/IntangibleAssetsTables</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Intangible Assets (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IntangibleAssetsDetails1</Role>
      <ShortName>Intangible Assets (Details 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/IntangibleAssetsTables</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2408404 - Disclosure - Intangible Assets (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/IntangibleAssetsDetailsTextual</Role>
      <ShortName>Intangible Assets (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/IntangibleAssetsTables</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>2409401 - Disclosure - Commitments and Contingencies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/CommitmentsAndContingenciesDetailsTextual</Role>
      <ShortName>Commitments and Contingencies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/CommitmentsAndContingencies</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - Product Warranties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ProductWarrantiesDetails</Role>
      <ShortName>Product Warranties (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/ProductWarrantiesTables</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>2410403 - Disclosure - Product Warranties (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ProductWarrantiesDetailsTextual</Role>
      <ShortName>Product Warranties (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/ProductWarrantiesTables</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>2412402 - Disclosure - Capital Stock and Stock Restrictions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/CapitalStockAndStockRestrictionsDetails</Role>
      <ShortName>Capital Stock and Stock Restrictions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/CapitalStockAndStockRestrictionsTables</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>2412403 - Disclosure - Capital Stock and Stock Restrictions (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/CapitalStockAndStockRestrictionsDetailsTextual</Role>
      <ShortName>Capital Stock and Stock Restrictions (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/CapitalStockAndStockRestrictionsTables</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>2413402 - Disclosure - Stock-Based Compensation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/StockBasedCompensationDetails</Role>
      <ShortName>Stock-Based Compensation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/StockBasedCompensationTables</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>2413403 - Disclosure - Stock-Based Compensation (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/StockBasedCompensationDetails1</Role>
      <ShortName>Stock-Based Compensation (Details 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/StockBasedCompensationTables</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>2413404 - Disclosure - Stock-based Compensation (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/StockBasedCompensationDetails2</Role>
      <ShortName>Stock-based Compensation (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>2413405 - Disclosure - Stock-Based Compensation (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/StockBasedCompensationDetails3</Role>
      <ShortName>Stock-Based Compensation (Details 3)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/StockBasedCompensationTables</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>2413406 - Disclosure - Stock-Based Compensation (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/StockBasedCompensationDetailsTextual</Role>
      <ShortName>Stock-Based Compensation (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/StockBasedCompensationTables</ParentRole>
      <Position>69</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>2416402 - Disclosure - Segment Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SegmentInformationDetails</Role>
      <ShortName>Segment Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/SegmentInformationTables</ParentRole>
      <Position>70</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>2416403 - Disclosure - Segment Information (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SegmentInformationDetails1</Role>
      <ShortName>Segment Information (Details 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/SegmentInformationTables</ParentRole>
      <Position>71</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>2416404 - Disclosure - Segment Information (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SegmentInformationDetails2</Role>
      <ShortName>Segment Information (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/SegmentInformationTables</ParentRole>
      <Position>72</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>2416405 - Disclosure - Segment Information (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SegmentInformationDetailsTextual</Role>
      <ShortName>Segment Information (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/SegmentInformationTables</ParentRole>
      <Position>73</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>2418402 - Disclosure - Restructuring Charge (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/RestructuringChargeDetails</Role>
      <ShortName>Restructuring Charge (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/RestructuringChargeTables</ParentRole>
      <Position>74</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>2418403 - Disclosure - Restructuring Charge (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/RestructuringChargeDetailsTextual</Role>
      <ShortName>Restructuring Charge (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/RestructuringChargeTables</ParentRole>
      <Position>75</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>2420402 - Disclosure - Fair Value Measurements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/FairValueMeasurementsDetails</Role>
      <ShortName>Fair Value Measurements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/FairValueMeasurementsTables</ParentRole>
      <Position>76</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>2421401 - Disclosure - Variable Interest Entity Variable Interest Entity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/VariableInterestEntityVariableInterestEntityDetails</Role>
      <ShortName>Variable Interest Entity Variable Interest Entity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/VariableInterestEntityVariableInterestEntity</ParentRole>
      <Position>77</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>2423401 - Disclosure - Benefit Plans Benefit Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/BenefitPlansBenefitPlansDetails</Role>
      <ShortName>Benefit Plans Benefit Plans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/BenefitPlansBenefitPlans</ParentRole>
      <Position>78</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>2425402 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://westell.com/role/SubsequentEventsNotes</ParentRole>
      <Position>79</Position>
    </Report>
    <Report instance="wstl-20200331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>2426401 - Schedule - Schedule II - Valuation and Qualifying Accounts Schedule II - Valuation and Qualifying Accounts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://westell.com/role/ScheduleIiValuationAndQualifyingAccountsScheduleIiValuationAndQualifyingAccountsDetails</Role>
      <ShortName>Schedule II - Valuation and Qualifying Accounts Schedule II - Valuation and Qualifying Accounts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>wstl-20200331.xml</File>
    <File>wstl-20200331.xsd</File>
    <File>wstl-20200331_cal.xml</File>
    <File>wstl-20200331_def.xml</File>
    <File>wstl-20200331_lab.xml</File>
    <File>wstl-20200331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/sic/2011-01-31</BaseTaxonomy>
    <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/2018-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2019-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
