<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.23.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>338</ContextCount>
  <ElementCount>323</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>92</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>10</UnitCount>
  <MyReports>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0000002 - Statement - UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/UNAUDITEDCONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS</Role>
      <ShortName>UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>0000003 - Statement - UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/UNAUDITEDCONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS</Role>
      <ShortName>UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>0000004 - Statement - UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/UNAUDITEDCONDENSEDCONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>0000005 - Statement - UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/UNAUDITEDCONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>0000006 - Statement - UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' DEFICIT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/UNAUDITEDCONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSDEFICIT</Role>
      <ShortName>UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' DEFICIT</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>0000007 - Disclosure - Basis of Presentation and Recent Developments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/BasisofPresentationandRecentDevelopments</Role>
      <ShortName>Basis of Presentation and Recent Developments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>0000008 - Disclosure - Acquisitions and Dispositions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/AcquisitionsandDispositions</Role>
      <ShortName>Acquisitions and Dispositions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>0000009 - Disclosure - Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/Revenue</Role>
      <ShortName>Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>0000010 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/EarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>0000011 - Disclosure - Deferred Acquisition Consideration</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/DeferredAcquisitionConsideration</Role>
      <ShortName>Deferred Acquisition Consideration</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>0000012 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>0000013 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>0000014 - Disclosure - Noncontrolling and Redeemable Noncontrolling Interests</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/NoncontrollingandRedeemableNoncontrollingInterests</Role>
      <ShortName>Noncontrolling and Redeemable Noncontrolling Interests</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>0000015 - Disclosure - Commitments, Contingencies and Guarantees</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/CommitmentsContingenciesandGuarantees</Role>
      <ShortName>Commitments, Contingencies and Guarantees</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>0000016 - Disclosure - Share Capital</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/ShareCapital</Role>
      <ShortName>Share Capital</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>0000017 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>0000018 - Disclosure - Supplemental Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/SupplementalInformation</Role>
      <ShortName>Supplemental Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>0000019 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>0000020 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/RelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>0000021 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>0000022 - Disclosure - Acquisitions and Dispositions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/AcquisitionsandDispositionsTables</Role>
      <ShortName>Acquisitions and Dispositions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/AcquisitionsandDispositions</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>0000023 - Disclosure - Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/RevenueTables</Role>
      <ShortName>Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/Revenue</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>0000024 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/EarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/EarningsPerShare</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>0000025 - Disclosure - Deferred Acquisition Consideration (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/DeferredAcquisitionConsiderationTables</Role>
      <ShortName>Deferred Acquisition Consideration (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/DeferredAcquisitionConsideration</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>0000026 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/Leases</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>0000027 - Disclosure - Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/DebtTables</Role>
      <ShortName>Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/Debt</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>0000028 - Disclosure - Noncontrolling and Redeemable Noncontrolling Interests (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/NoncontrollingandRedeemableNoncontrollingInterestsTables</Role>
      <ShortName>Noncontrolling and Redeemable Noncontrolling Interests (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/NoncontrollingandRedeemableNoncontrollingInterests</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>0000029 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/FairValueMeasurements</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>0000030 - Disclosure - Related Party Disclosures (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/RelatedPartyDisclosuresTables</Role>
      <ShortName>Related Party Disclosures (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>0000031 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/SegmentInformation</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>0000032 - Disclosure - Basis of Presentation and Recent Developments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/BasisofPresentationandRecentDevelopmentsDetails</Role>
      <ShortName>Basis of Presentation and Recent Developments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/BasisofPresentationandRecentDevelopments</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>0000033 - Disclosure - Acquisitions and Dispositions - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/AcquisitionsandDispositionsNarrativeDetails</Role>
      <ShortName>Acquisitions and Dispositions - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>0000034 - Disclosure - Acquisitions and Dispositions - Assets Acquired and Liabilities Assumed (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/AcquisitionsandDispositionsAssetsAcquiredandLiabilitiesAssumedDetails</Role>
      <ShortName>Acquisitions and Dispositions - Assets Acquired and Liabilities Assumed (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>0000035 - Disclosure - Acquisitions and Dispositions - Intangible Assets Acquired (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/AcquisitionsandDispositionsIntangibleAssetsAcquiredDetails</Role>
      <ShortName>Acquisitions and Dispositions - Intangible Assets Acquired (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>0000036 - Disclosure - Acquisitions and Dispositions - Pro Forma (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/AcquisitionsandDispositionsProFormaDetails</Role>
      <ShortName>Acquisitions and Dispositions - Pro Forma (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>0000037 - Disclosure - Revenue - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/RevenueAdditionalInformationDetails</Role>
      <ShortName>Revenue - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>0000038 - Disclosure - Revenue - Disaggregation of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/RevenueDisaggregationofRevenueDetails</Role>
      <ShortName>Revenue - Disaggregation of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>0000039 - Disclosure - Revenue - Contract Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/RevenueContractAssetsandLiabilitiesDetails</Role>
      <ShortName>Revenue - Contract Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>0000040 - Disclosure - Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/EarningsPerShareDetails</Role>
      <ShortName>Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/EarningsPerShareTables</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>0000041 - Disclosure - Deferred Acquisition Consideration (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/DeferredAcquisitionConsiderationDetails</Role>
      <ShortName>Deferred Acquisition Consideration (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/DeferredAcquisitionConsiderationTables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>0000042 - Disclosure - Leases - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/LeasesAdditionalInformationDetails</Role>
      <ShortName>Leases - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>0000043 - Disclosure - Leases - Lease Costs and Other Quantitative Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/LeasesLeaseCostsandOtherQuantitativeInformationDetails</Role>
      <ShortName>Leases - Lease Costs and Other Quantitative Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>0000044 - Disclosure - Leases - Minimum Future Rental Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/LeasesMinimumFutureRentalPaymentsDetails</Role>
      <ShortName>Leases - Minimum Future Rental Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>0000045 - Disclosure - Debt - Schedule of Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/DebtScheduleofDebtDetails</Role>
      <ShortName>Debt - Schedule of Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>0000046 - Disclosure - Debt - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/DebtAdditionalInformationDetails</Role>
      <ShortName>Debt - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>0000047 - Disclosure - Noncontrolling and Redeemable Noncontrolling Interests - Noncontrolling Interests (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/NoncontrollingandRedeemableNoncontrollingInterestsNoncontrollingInterestsDetails</Role>
      <ShortName>Noncontrolling and Redeemable Noncontrolling Interests - Noncontrolling Interests (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>0000048 - Disclosure - Noncontrolling and Redeemable Noncontrolling Interests - Changes in Redeemable Noncontrolling Interests (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/NoncontrollingandRedeemableNoncontrollingInterestsChangesinRedeemableNoncontrollingInterestsDetails</Role>
      <ShortName>Noncontrolling and Redeemable Noncontrolling Interests - Changes in Redeemable Noncontrolling Interests (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>0000049 - Disclosure - Noncontrolling and Redeemable Noncontrolling Interests (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/NoncontrollingandRedeemableNoncontrollingInterestsDetailsTextual</Role>
      <ShortName>Noncontrolling and Redeemable Noncontrolling Interests (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/NoncontrollingandRedeemableNoncontrollingInterestsTables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>0000050 - Disclosure - Commitments, Contingencies and Guarantees (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/CommitmentsContingenciesandGuaranteesDetailsTextual</Role>
      <ShortName>Commitments, Contingencies and Guarantees (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/CommitmentsContingenciesandGuarantees</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>0000051 - Disclosure - Share Capital (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/ShareCapitalDetailsTextual</Role>
      <ShortName>Share Capital (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/ShareCapital</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>0000052 - Disclosure - Fair Value Measurements - Financial Instruments not measured at Fair Value on a Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/FairValueMeasurementsFinancialInstrumentsnotmeasuredatFairValueonaRecurringBasisDetails</Role>
      <ShortName>Fair Value Measurements - Financial Instruments not measured at Fair Value on a Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>0000053 - Disclosure - Fair Value Measurements - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/FairValueMeasurementsAdditionalInformationDetails</Role>
      <ShortName>Fair Value Measurements - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>0000054 - Disclosure - Supplemental Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/SupplementalInformationDetails</Role>
      <ShortName>Supplemental Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/SupplementalInformation</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>0000055 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/IncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/IncomeTaxes</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>0000056 - Disclosure - Related Party Transactions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/RelatedPartyTransactionsDetails</Role>
      <ShortName>Related Party Transactions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/RelatedPartyTransactions</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="stgw-20230630.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>0000057 - Disclosure - Segment Information (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagwellglobal.com/role/SegmentInformationDetails1</Role>
      <ShortName>Segment Information (Details 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.stagwellglobal.com/role/SegmentInformationTables</ParentRole>
      <Position>57</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept RevenueFromRelatedParties in us-gaap/2022 used in 28 facts was deprecated in us-gaap/2023 as of 2023 and should not be used. stgw-20230630.htm 4</Log>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept DueFromRelatedParties in us-gaap/2022 used in 14 facts was deprecated in us-gaap/2023 as of 2023 and should not be used. stgw-20230630.htm 4</Log>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept NotesReceivableRelatedParties in us-gaap/2022 used in 2 facts was deprecated in us-gaap/2023 as of 2023 and should not be used. stgw-20230630.htm 4</Log>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept InterestIncomeRelatedParty in us-gaap/2022 used in 4 facts was deprecated in us-gaap/2023 as of 2023 and should not be used. stgw-20230630.htm 4</Log>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty in us-gaap/2022 used in 4 facts was deprecated in us-gaap/2023 as of 2023 and should not be used. stgw-20230630.htm 4</Log>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept DueToRelatedPartiesCurrentAndNoncurrent in us-gaap/2022 used in 2 facts was deprecated in us-gaap/2023 as of 2023 and should not be used. stgw-20230630.htm 4</Log>
    <Log type="Warning">[ix-0514-Hidden-Fact-Eligible-For-Transform] WARN: 3 fact(s) appearing in ix:hidden were eligible for transformation: us-gaap:RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1 -  stgw-20230630.htm 4</Log>
  </Logs>
  <InputFiles>
    <File doctype="10-Q" original="stgw-20230630.htm">stgw-20230630.htm</File>
    <File>stgw-20230630.xsd</File>
    <File>stgw-20230630_cal.xml</File>
    <File>stgw-20230630_def.xml</File>
    <File>stgw-20230630_lab.xml</File>
    <File>stgw-20230630_pre.xml</File>
    <File>stgw-2023630xex311xmpenn.htm</File>
    <File>stgw-2023630xex312xflanuto.htm</File>
    <File>stgw-2023630xex321xmpenn.htm</File>
    <File>stgw-2023630xex322xflanuto.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>stgw-20230630_g1.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="1084">http://fasb.org/us-gaap/2022</BaseTaxonomy>
    <BaseTaxonomy items="30">http://xbrl.sec.gov/dei/2022</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
