<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.8.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>116</ContextCount>
  <ElementCount>214</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>46</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>9</UnitCount>
  <MyReports>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CondensedConsolidatedBalanceSheets</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001001 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - Condensed Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CondensedConsolidatedStatementsOfOperations</Role>
      <ShortName>Condensed Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003000 - Statement - Condensed Consolidated Statements of Comprehensive Income (Loss)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeLoss</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income (Loss)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1030000 - Statement - Condensed Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - The Company and Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CompanyAndSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>The Company and Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Recent Accounting Pronouncements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/RecentAccountingPronouncements</Role>
      <ShortName>Recent Accounting Pronouncements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/EarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Balance Sheets Components</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/BalanceSheetsComponents</Role>
      <ShortName>Balance Sheets Components</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2119100 - Disclosure - Long-term Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/LongTermDebt</Role>
      <ShortName>Long-term Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2125100 - Disclosure - Stockholders??? Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/StockholdersEquity</Role>
      <ShortName>Stockholders??? Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2128100 - Disclosure - Stock-based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/StockBasedCompensation</Role>
      <ShortName>Stock-based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2134100 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2137100 - Disclosure - Employee Benefit Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/EmployeeBenefitPlans</Role>
      <ShortName>Employee Benefit Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2143100 - Disclosure - Related Party transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/RelatedPartyTransactions</Role>
      <ShortName>Related Party transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2201201 - Disclosure - The Company and Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CompanyAndSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>The Company and Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/CompanyAndSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/EarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/EarningsPerShare</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - Balance Sheets Components (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/BalanceSheetsComponentsTables</Role>
      <ShortName>Balance Sheets Components (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/BalanceSheetsComponents</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2313301 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/FairValueMeasurements</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2316301 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/CommitmentsAndContingencies</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2319301 - Disclosure - Long-term Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/LongTermDebtTables</Role>
      <ShortName>Long-term Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/LongTermDebt</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2325301 - Disclosure - Stockholders??? Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/StockholdersEquityTables</Role>
      <ShortName>Stockholders??? Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/StockholdersEquity</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2328301 - Disclosure - Stock-based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/StockBasedCompensationTables</Role>
      <ShortName>Stock-based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/StockBasedCompensation</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2401402 - Disclosure - The Company and Summary of Significant Accounting Policies (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CompanyAndSummaryOfSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>The Company and Summary of Significant Accounting Policies (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/CompanyAndSummaryOfSignificantAccountingPoliciesPolicies</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Earnings Per Share (Schedule of Eanings Per Share) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/EarningsPerShareScheduleOfEaningsPerShareDetails</Role>
      <ShortName>Earnings Per Share (Schedule of Eanings Per Share) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/EarningsPerShareTables</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Earnings Per Share (Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/EarningsPerShareScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareDetails</Role>
      <ShortName>Earnings Per Share (Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/EarningsPerShareTables</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - Balance Sheets Components (Marketable Securities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/BalanceSheetsComponentsMarketableSecuritiesDetails</Role>
      <ShortName>Balance Sheets Components (Marketable Securities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/BalanceSheetsComponentsTables</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2410403 - Disclosure - Balance Sheets Components (Amortized Cost and Fair Value) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/BalanceSheetsComponentsAmortizedCostAndFairValueDetails</Role>
      <ShortName>Balance Sheets Components (Amortized Cost and Fair Value) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/BalanceSheetsComponentsTables</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2410404 - Disclosure - Balance Sheets Components (Schedule of Property and Equipment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/BalanceSheetsComponentsScheduleOfPropertyAndEquipmentDetails</Role>
      <ShortName>Balance Sheets Components (Schedule of Property and Equipment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/BalanceSheetsComponentsTables</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2410405 - Disclosure - Balance Sheets Components (Schedule of Inventory) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/BalanceSheetsComponentsScheduleOfInventoryDetails</Role>
      <ShortName>Balance Sheets Components (Schedule of Inventory) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/BalanceSheetsComponentsTables</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2410406 - Disclosure - Balance Sheets Components (Accrued Liabilities and Other Current Liabilities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/BalanceSheetsComponentsAccruedLiabilitiesAndOtherCurrentLiabilitiesDetails</Role>
      <ShortName>Balance Sheets Components (Accrued Liabilities and Other Current Liabilities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/BalanceSheetsComponentsTables</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2413402 - Disclosure - Fair Value Measurements (Assets, Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/FairValueMeasurementsAssetsRecurringBasisDetails</Role>
      <ShortName>Fair Value Measurements (Assets, Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/FairValueMeasurementsTables</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2413403 - Disclosure - Fair Value Measurements (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/FairValueMeasurementsNarrativeDetails</Role>
      <ShortName>Fair Value Measurements (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/FairValueMeasurementsTables</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2413404 - Disclosure - Fair Value Measurements (Schedule of Warrants) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/FairValueMeasurementsScheduleOfWarrantsDetails</Role>
      <ShortName>Fair Value Measurements (Schedule of Warrants) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/FairValueMeasurementsTables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2416402 - Disclosure - Commitments and Contingencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CommitmentsAndContingenciesDetails</Role>
      <ShortName>Commitments and Contingencies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/CommitmentsAndContingenciesTables</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2416403 - Disclosure - Commitments and Contingencies (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CommitmentsAndContingenciesNarrativeDetails</Role>
      <ShortName>Commitments and Contingencies (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/CommitmentsAndContingenciesTables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2416404 - Disclosure - Commitments and Contingencies (RUSNANO) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/CommitmentsAndContingenciesRusnanoDetails</Role>
      <ShortName>Commitments and Contingencies (RUSNANO) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/CommitmentsAndContingenciesTables</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2419402 - Disclosure - Long-term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/LongTermDebtDetails</Role>
      <ShortName>Long-term Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/LongTermDebtTables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2419403 - Disclosure - Long-term Debt (Schedule of Maturities of Long-term Debt) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/LongTermDebtScheduleOfMaturitiesOfLongTermDebtDetails</Role>
      <ShortName>Long-term Debt (Schedule of Maturities of Long-term Debt) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/LongTermDebtTables</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2425402 - Disclosure - Stockholders??? Equity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/StockholdersEquityDetails</Role>
      <ShortName>Stockholders??? Equity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/StockholdersEquityTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2425403 - Disclosure - Stockholders??? Equity (Narrative 1) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/StockholdersEquityNarrative1Details</Role>
      <ShortName>Stockholders??? Equity (Narrative 1) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/StockholdersEquityTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2425404 - Disclosure - Stockholders??? Equity (Narrative 2) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/StockholdersEquityNarrative2Details</Role>
      <ShortName>Stockholders??? Equity (Narrative 2) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/StockholdersEquityTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2428402 - Disclosure - Stock-based Compensation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/StockBasedCompensationDetails</Role>
      <ShortName>Stock-based Compensation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/StockBasedCompensationTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2428403 - Disclosure - Stock-based Compensation (Equity Based Awards Compensation Costs) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/StockBasedCompensationEquityBasedAwardsCompensationCostsDetails</Role>
      <ShortName>Stock-based Compensation (Equity Based Awards Compensation Costs) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/StockBasedCompensationTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2434401 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/IncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/IncomeTaxes</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2437401 - Disclosure - Employee Benefit Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/EmployeeBenefitPlansDetails</Role>
      <ShortName>Employee Benefit Plans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/EmployeeBenefitPlans</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="qtna-20171001.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2443401 - Disclosure - Related Party transactions (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.quantenna.com/role/RelatedPartyTransactionsNarrativeDetails</Role>
      <ShortName>Related Party transactions (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.quantenna.com/role/RelatedPartyTransactions</ParentRole>
      <Position>50</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>qtna-20171001.xml</File>
    <File>qtna-20171001.xsd</File>
    <File>qtna-20171001_cal.xml</File>
    <File>qtna-20171001_def.xml</File>
    <File>qtna-20171001_lab.xml</File>
    <File>qtna-20171001_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2014-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2016-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
