<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>188</ContextCount>
  <ElementCount>250</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>39</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001002 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002003 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVELOSS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1003004 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1004005 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005006 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITYDEFICIT</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1006007 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITYDEFICITParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1007008 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2101101 - Disclosure - Organization and Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/OrganizationandBusiness</Role>
      <ShortName>Organization and Business</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2102102 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/SummaryofSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2105103 - Disclosure - Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/Revenue</Role>
      <ShortName>Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2110104 - Disclosure - Collaboration, License, and Supply Agreements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CollaborationLicenseandSupplyAgreements</Role>
      <ShortName>Collaboration, License, and Supply Agreements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2112105 - Disclosure - Cash, Cash Equivalents, and Restricted Cash</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CashCashEquivalentsandRestrictedCash</Role>
      <ShortName>Cash, Cash Equivalents, and Restricted Cash</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2115106 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2118107 - Disclosure - Inventory</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/Inventory</Role>
      <ShortName>Inventory</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2121108 - Disclosure - Intangible Assets and Goodwill</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/IntangibleAssetsandGoodwill</Role>
      <ShortName>Intangible Assets and Goodwill</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2126109 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2128110 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2133111 - Disclosure - Stockholders' Equity (Deficit)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockholdersEquityDeficit</Role>
      <ShortName>Stockholders' Equity (Deficit)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2135112 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2143113 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2145114 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2146115 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2203201 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/SummaryofSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.novavax.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/RevenueTables</Role>
      <ShortName>Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.novavax.com/role/Revenue</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2313302 - Disclosure - Cash, Cash Equivalents, and Restricted Cash (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CashCashEquivalentsandRestrictedCashTables</Role>
      <ShortName>Cash, Cash Equivalents, and Restricted Cash (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.novavax.com/role/CashCashEquivalentsandRestrictedCash</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2316303 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.novavax.com/role/FairValueMeasurements</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2319304 - Disclosure - Inventory (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/InventoryTables</Role>
      <ShortName>Inventory (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.novavax.com/role/Inventory</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2322305 - Disclosure - Intangible Assets and Goodwill (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/IntangibleAssetsandGoodwillTables</Role>
      <ShortName>Intangible Assets and Goodwill (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.novavax.com/role/IntangibleAssetsandGoodwill</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2329306 - Disclosure - Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/DebtTables</Role>
      <ShortName>Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.novavax.com/role/Debt</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2336307 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.novavax.com/role/StockBasedCompensation</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2404401 - Disclosure - Summary of Significant Accounting Policies - Basis of Presentation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/SummaryofSignificantAccountingPoliciesBasisofPresentationDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Basis of Presentation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Revenue - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/RevenueAdditionalInformationDetails</Role>
      <ShortName>Revenue - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Revenue - Accounts Receivable, Unbilled Services, and Deferred Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/RevenueAccountsReceivableUnbilledServicesandDeferredRevenueDetails</Role>
      <ShortName>Revenue - Accounts Receivable, Unbilled Services, and Deferred Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2409404 - Disclosure - Revenue - Schedule of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/RevenueScheduleofRevenueDetails</Role>
      <ShortName>Revenue - Schedule of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2411405 - Disclosure - Collaboration, License, and Supply Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CollaborationLicenseandSupplyAgreementsDetails</Role>
      <ShortName>Collaboration, License, and Supply Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.novavax.com/role/CollaborationLicenseandSupplyAgreements</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2414406 - Disclosure - Cash, Cash Equivalents, and Restricted Cash (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/CashCashEquivalentsandRestrictedCashDetails</Role>
      <ShortName>Cash, Cash Equivalents, and Restricted Cash (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.novavax.com/role/CashCashEquivalentsandRestrictedCashTables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2417407 - Disclosure - Fair Value Measurements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/FairValueMeasurementsDetails</Role>
      <ShortName>Fair Value Measurements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.novavax.com/role/FairValueMeasurementsTables</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2420408 - Disclosure - Inventory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/InventoryDetails</Role>
      <ShortName>Inventory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.novavax.com/role/InventoryTables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2423409 - Disclosure - Intangible Assets and Goodwill - Identifiable Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/IntangibleAssetsandGoodwillIdentifiableIntangibleAssetsDetails</Role>
      <ShortName>Intangible Assets and Goodwill - Identifiable Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2424410 - Disclosure - Intangible Assets and Goodwill - Identifiable Intangible Assets, estimated amortization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/IntangibleAssetsandGoodwillIdentifiableIntangibleAssetsestimatedamortizationDetails</Role>
      <ShortName>Intangible Assets and Goodwill - Identifiable Intangible Assets, estimated amortization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2425411 - Disclosure - Intangible Assets and Goodwill - Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/IntangibleAssetsandGoodwillGoodwillDetails</Role>
      <ShortName>Intangible Assets and Goodwill - Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2427412 - Disclosure - Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/LeasesDetails</Role>
      <ShortName>Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.novavax.com/role/Leases</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2430413 - Disclosure - Debt - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/DebtNarrativeDetails</Role>
      <ShortName>Debt - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2431414 - Disclosure - Debt - Notes Payable (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.novavax.com/role/DebtNotesPayableDetails</Role>
      <ShortName>Debt - Notes Payable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2432415 - Disclosure - Debt - Interest Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/DebtInterestExpenseDetails</Role>
      <ShortName>Debt - Interest Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2434416 - Disclosure - Stockholders' Equity (Deficit) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockholdersEquityDeficitDetails</Role>
      <ShortName>Stockholders' Equity (Deficit) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.novavax.com/role/StockholdersEquityDeficit</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2437417 - Disclosure - Stock-Based Compensation - Stock Options (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockBasedCompensationStockOptionsDetails</Role>
      <ShortName>Stock-Based Compensation - Stock Options (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2438418 - Disclosure - Stock-Based Compensation - Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockBasedCompensationCompensationExpenseDetails</Role>
      <ShortName>Stock-Based Compensation - Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2439419 - Disclosure - Stock-Based Compensation - Stock Options and Appreciation Rights (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockBasedCompensationStockOptionsandAppreciationRightsDetails</Role>
      <ShortName>Stock-Based Compensation - Stock Options and Appreciation Rights (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2440420 - Disclosure - Stock-Based Compensation - Stock Options and Appreciation Rights, Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockBasedCompensationStockOptionsandAppreciationRightsAssumptionsDetails</Role>
      <ShortName>Stock-Based Compensation - Stock Options and Appreciation Rights, Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2441421 - Disclosure - Stock-Based Compensation - Restricted Stock Units (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockBasedCompensationRestrictedStockUnitsDetails</Role>
      <ShortName>Stock-Based Compensation - Restricted Stock Units (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2442422 - Disclosure - Stock-Based Compensation - Employee Stock Purchase Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/StockBasedCompensationEmployeeStockPurchasePlanDetails</Role>
      <ShortName>Stock-Based Compensation - Employee Stock Purchase Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2444423 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/IncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.novavax.com/role/IncomeTaxes</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="nvax-20220630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2447424 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.novavax.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.novavax.com/role/SubsequentEvents</ParentRole>
      <Position>55</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="nvax-20220630.htm">nvax-20220630.htm</File>
    <File>nvax-20220630.xsd</File>
    <File>nvax-20220630_cal.xml</File>
    <File>nvax-20220630_def.xml</File>
    <File>nvax-20220630_lab.xml</File>
    <File>nvax-20220630_pre.xml</File>
    <File>nvax-20220630xex103.htm</File>
    <File>nvax-20220630xex104.htm</File>
    <File>nvax-20220630xex105.htm</File>
    <File>nvax-20220630xex311.htm</File>
    <File>nvax-20220630xex312.htm</File>
    <File>nvax-20220630xex321.htm</File>
    <File>nvax-20220630xex322.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>nvax-20220630_g1.jpg</File>
    <File>nvax-20220630_g2.jpg</File>
    <File>nvax-20220630_g3.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="628">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>
