<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>195</ContextCount>
  <ElementCount>332</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>49</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001001 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001002 - Statement - Condensed Consolidated Balance Sheets - Unaudited</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/CondensedConsolidatedBalanceSheetsUnaudited</Role>
      <ShortName>Condensed Consolidated Balance Sheets - Unaudited</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002003 - Statement - Condensed Consolidated Balance Sheets - Unaudited (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/CondensedConsolidatedBalanceSheetsUnauditedParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets - Unaudited (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1003004 - Statement - Condensed Consolidated Statements of Operations - Unaudited</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/CondensedConsolidatedStatementsofOperationsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Operations - Unaudited</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1004005 - Statement - Condensed Consolidated Statements of Comprehensive Loss - Unaudited</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/CondensedConsolidatedStatementsofComprehensiveLossUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Loss - Unaudited</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005006 - Statement - Condensed Consolidated Statements of Stockholders' Equity - Unaudited</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/CondensedConsolidatedStatementsofStockholdersEquityUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Stockholders' Equity - Unaudited</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1006007 - Statement - Condensed Consolidated Statements of Cash Flows - Unaudited</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/CondensedConsolidatedStatementsofCashFlowsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows - Unaudited</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2101101 - Disclosure - The Company and Summary of Significant Accounting Principles</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/TheCompanyandSummaryofSignificantAccountingPrinciples</Role>
      <ShortName>The Company and Summary of Significant Accounting Principles</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2105102 - Disclosure - Revenue from Contracts with Customers</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/RevenuefromContractswithCustomers</Role>
      <ShortName>Revenue from Contracts with Customers</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2111103 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2117104 - Disclosure - Goodwill and Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/GoodwillandIntangibleAssets</Role>
      <ShortName>Goodwill and Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2123105 - Disclosure - Property and Equipment - Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/PropertyandEquipmentNet</Role>
      <ShortName>Property and Equipment - Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2128106 - Disclosure - Accrued Expenses and Other Current Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/AccruedExpensesandOtherCurrentLiabilities</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2131107 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2136108 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2137109 - Disclosure - Stock-based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/StockbasedCompensation</Role>
      <ShortName>Stock-based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2145110 - Disclosure - Net Loss Per Common Share Data</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/NetLossPerCommonShareData</Role>
      <ShortName>Net Loss Per Common Share Data</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2148111 - Disclosure - Merger Agreement with Qumu Corporation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/MergerAgreementwithQumuCorporation</Role>
      <ShortName>Merger Agreement with Qumu Corporation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2150112 - Disclosure - Subsequent Event</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/SubsequentEvent</Role>
      <ShortName>Subsequent Event</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - The Company and Summary of Significant Accounting Principles (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/TheCompanyandSummaryofSignificantAccountingPrinciplesPolicies</Role>
      <ShortName>The Company and Summary of Significant Accounting Principles (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://synacor.com/role/TheCompanyandSummaryofSignificantAccountingPrinciples</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - The Company and Summary of Significant Accounting Principles (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/TheCompanyandSummaryofSignificantAccountingPrinciplesTables</Role>
      <ShortName>The Company and Summary of Significant Accounting Principles (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://synacor.com/role/TheCompanyandSummaryofSignificantAccountingPrinciples</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2306302 - Disclosure - Revenue from Contracts with Customers (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/RevenuefromContractswithCustomersTables</Role>
      <ShortName>Revenue from Contracts with Customers (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://synacor.com/role/RevenuefromContractswithCustomers</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2312303 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://synacor.com/role/Leases</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2318304 - Disclosure - Goodwill and Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/GoodwillandIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://synacor.com/role/GoodwillandIntangibleAssets</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2324305 - Disclosure - Property and Equipment - Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/PropertyandEquipmentNetTables</Role>
      <ShortName>Property and Equipment - Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://synacor.com/role/PropertyandEquipmentNet</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2329306 - Disclosure - Accrued Expenses and Other Current Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/AccruedExpensesandOtherCurrentLiabilitiesTables</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://synacor.com/role/AccruedExpensesandOtherCurrentLiabilities</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2332307 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://synacor.com/role/SegmentInformation</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2338308 - Disclosure - Stock-based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/StockbasedCompensationTables</Role>
      <ShortName>Stock-based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://synacor.com/role/StockbasedCompensation</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2346309 - Disclosure - Net Loss Per Common Share Data (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/NetLossPerCommonShareDataTables</Role>
      <ShortName>Net Loss Per Common Share Data (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://synacor.com/role/NetLossPerCommonShareData</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2404401 - Disclosure - The Company and Summary of Significant Accounting Principles - Schedule of Concentrations Equal to or Exceeding 10% of Company's Accounts Receivable, Revenue, and Cost of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/TheCompanyandSummaryofSignificantAccountingPrinciplesScheduleofConcentrationsEqualtoorExceeding10ofCompanysAccountsReceivableRevenueandCostofRevenueDetails</Role>
      <ShortName>The Company and Summary of Significant Accounting Principles - Schedule of Concentrations Equal to or Exceeding 10% of Company's Accounts Receivable, Revenue, and Cost of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Revenue from Contracts with Customers - Summary of Timing of Revenue Recognition, Includes Reconciliation of Disaggregated by Reportable Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/RevenuefromContractswithCustomersSummaryofTimingofRevenueRecognitionIncludesReconciliationofDisaggregatedbyReportableSegmentDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Summary of Timing of Revenue Recognition, Includes Reconciliation of Disaggregated by Reportable Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Revenue from Contracts with Customers - Schedule of Contract with Customer, Asset and Liability (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/RevenuefromContractswithCustomersScheduleofContractwithCustomerAssetandLiabilityDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Schedule of Contract with Customer, Asset and Liability (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2409404 - Disclosure - Revenue from Contracts with Customers - Schedule of Changes in Deferred Revenue, Inclusive of Both Current and Long-term (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/RevenuefromContractswithCustomersScheduleofChangesinDeferredRevenueInclusiveofBothCurrentandLongtermDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Schedule of Changes in Deferred Revenue, Inclusive of Both Current and Long-term (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2410405 - Disclosure - Revenue from Contracts with Customers - Remaining Performance Obligations - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/RevenuefromContractswithCustomersRemainingPerformanceObligationsAdditionalInformationDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Remaining Performance Obligations - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2413406 - Disclosure - Leases - Schedule of Components of Lease Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/LeasesScheduleofComponentsofLeaseCostsDetails</Role>
      <ShortName>Leases - Schedule of Components of Lease Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2414407 - Disclosure - Leases - Schedule of Lease Term and Discount Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/LeasesScheduleofLeaseTermandDiscountRateDetails</Role>
      <ShortName>Leases - Schedule of Lease Term and Discount Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2415408 - Disclosure - Leases - Schedule of Maturities of Operating and Finance Leases Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/LeasesScheduleofMaturitiesofOperatingandFinanceLeasesLiabilitiesDetails</Role>
      <ShortName>Leases - Schedule of Maturities of Operating and Finance Leases Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2416409 - Disclosure - Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/LeasesScheduleofSupplementalCashFlowInformationRelatedtoLeasesDetails</Role>
      <ShortName>Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2419410 - Disclosure - Goodwill and Intangible Assets - Schedule of Changes in the Carrying Amount of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/GoodwillandIntangibleAssetsScheduleofChangesintheCarryingAmountofGoodwillDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Changes in the Carrying Amount of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2420411 - Disclosure - Goodwill and Intangible Assets - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/GoodwillandIntangibleAssetsAdditionalInformationDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2421412 - Disclosure - Goodwill and Intangible Assets - Schedule of Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/GoodwillandIntangibleAssetsScheduleofIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2422413 - Disclosure - Goodwill and Intangible Assets - Estimated Future Amortization of Acquired Intangibles (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/GoodwillandIntangibleAssetsEstimatedFutureAmortizationofAcquiredIntangiblesDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Estimated Future Amortization of Acquired Intangibles (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2425414 - Disclosure - Property and Equipment - Net - Schedule of Property and Equipment (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/PropertyandEquipmentNetScheduleofPropertyandEquipmentDetail</Role>
      <ShortName>Property and Equipment - Net - Schedule of Property and Equipment (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2426415 - Disclosure - Property and Equipment - Net - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/PropertyandEquipmentNetAdditionalInformationDetail</Role>
      <ShortName>Property and Equipment - Net - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2427416 - Disclosure - Property and Equipment - Net - Schedule of Long Lived Tangible Assets by Geographic Area (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/PropertyandEquipmentNetScheduleofLongLivedTangibleAssetsbyGeographicAreaDetails</Role>
      <ShortName>Property and Equipment - Net - Schedule of Long Lived Tangible Assets by Geographic Area (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2430417 - Disclosure - Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/AccruedExpensesandOtherCurrentLiabilitiesScheduleofAccruedExpensesandOtherCurrentLiabilitiesDetails</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2433418 - Disclosure - Segment Information - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/SegmentInformationAdditionalInformationDetails</Role>
      <ShortName>Segment Information - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2434419 - Disclosure - Segment Information - Summary of Financial Information for Companies Reportable Segments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/SegmentInformationSummaryofFinancialInformationforCompaniesReportableSegmentsDetails</Role>
      <ShortName>Segment Information - Summary of Financial Information for Companies Reportable Segments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2435420 - Disclosure - Segment Information - Reconciliation of Total Segment Adjusted EBITDA to Net Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/SegmentInformationReconciliationofTotalSegmentAdjustedEBITDAtoNetLossDetails</Role>
      <ShortName>Segment Information - Reconciliation of Total Segment Adjusted EBITDA to Net Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2439421 - Disclosure - Stock-based Compensation - Schedule of Weighted-Average Assumptions Used to Estimate the Fair Value of Options Granted (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/StockbasedCompensationScheduleofWeightedAverageAssumptionsUsedtoEstimatetheFairValueofOptionsGrantedDetails</Role>
      <ShortName>Stock-based Compensation - Schedule of Weighted-Average Assumptions Used to Estimate the Fair Value of Options Granted (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2440422 - Disclosure - Stock-based Compensation - Schedule of Total Stock Based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/StockbasedCompensationScheduleofTotalStockBasedCompensationExpenseDetails</Role>
      <ShortName>Stock-based Compensation - Schedule of Total Stock Based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2441423 - Disclosure - Stock-based Compensation - Summary of Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/StockbasedCompensationSummaryofStockOptionActivityDetails</Role>
      <ShortName>Stock-based Compensation - Summary of Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2442424 - Disclosure - Stock-based Compensation - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/StockbasedCompensationAdditionalInformationDetails</Role>
      <ShortName>Stock-based Compensation - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2443425 - Disclosure - Stock-based Compensation - Summary of RSU Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/StockbasedCompensationSummaryofRSUActivityDetails</Role>
      <ShortName>Stock-based Compensation - Summary of RSU Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2444426 - Disclosure - Stock-based Compensation - Summary of PSU Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/StockbasedCompensationSummaryofPSUActivityDetails</Role>
      <ShortName>Stock-based Compensation - Summary of PSU Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2447427 - Disclosure - Net Loss Per Common Share Data - Schedule of Securities Excluded from Calculation of Diluted Net Loss Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/NetLossPerCommonShareDataScheduleofSecuritiesExcludedfromCalculationofDilutedNetLossPerShareDetails</Role>
      <ShortName>Net Loss Per Common Share Data - Schedule of Securities Excluded from Calculation of Diluted Net Loss Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2449428 - Disclosure - Merger Agreement with Qumu Corporation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/MergerAgreementwithQumuCorporationDetails</Role>
      <ShortName>Merger Agreement with Qumu Corporation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://synacor.com/role/MergerAgreementwithQumuCorporation</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="sync-20200630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2451429 - Disclosure - Subsequent Event (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://synacor.com/role/SubsequentEventDetails</Role>
      <ShortName>Subsequent Event (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://synacor.com/role/SubsequentEvent</ParentRole>
      <Position>58</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="sync-20200630.htm">sync-20200630.htm</File>
    <File>sync-20200630.xsd</File>
    <File>sync-20200630_cal.xml</File>
    <File>sync-20200630_def.xml</File>
    <File>sync-20200630_lab.xml</File>
    <File>sync-20200630_pre.xml</File>
    <File>sync-20200630xexx311.htm</File>
    <File>sync-20200630xexx312.htm</File>
    <File>sync-20200630xexx321.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>sync-20200630_g1.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy>http://fasb.org/srt/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/country/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
