<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>362</ContextCount>
  <ElementCount>551</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>110</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0002002 - Document - Audit Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/AuditInformation</Role>
      <ShortName>Audit Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001003 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Uncategorized</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002004 - Statement - Consolidated Balance Sheet (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ConsolidatedBalanceSheetParenthetical</Role>
      <ShortName>Consolidated Balance Sheet (Parenthetical)</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003005 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ConsolidatedStatementsofOperations</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1004006 - Statement - Consolidated Statements of Comprehensive (Loss) Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ConsolidatedStatementsofComprehensiveLossIncome</Role>
      <ShortName>Consolidated Statements of Comprehensive (Loss) Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1005007 - Statement - Consolidated Statements of Stockholders' Deficit / Members' Deficit</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ConsolidatedStatementsofStockholdersDeficitMembersDeficit</Role>
      <ShortName>Consolidated Statements of Stockholders' Deficit / Members' Deficit</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1006008 - Statement - Consolidated Statement of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ConsolidatedStatementofCashFlows</Role>
      <ShortName>Consolidated Statement of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2101101 - Disclosure - Organization</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/Organization</Role>
      <ShortName>Organization</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2103102 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/SummaryofSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2106103 - Disclosure - Revenue Recognition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/RevenueRecognition</Role>
      <ShortName>Revenue Recognition</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2112104 - Disclosure - Acquisitions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/Acquisitions</Role>
      <ShortName>Acquisitions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2116105 - Disclosure - Goodwill and Intangible Assets, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/GoodwillandIntangibleAssetsNet</Role>
      <ShortName>Goodwill and Intangible Assets, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2122106 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2128107 - Disclosure - Balance Sheet Components</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/BalanceSheetComponents</Role>
      <ShortName>Balance Sheet Components</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2132108 - Disclosure - Derivative Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/DerivativeFinancialInstruments</Role>
      <ShortName>Derivative Financial Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2135109 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2137110 - Disclosure - Commitment and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/CommitmentandContingencies</Role>
      <ShortName>Commitment and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2143111 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/StockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2151112 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/EarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2155113 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2161114 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/RelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2163115 - Disclosure - Variable Interest Entities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/VariableInterestEntities</Role>
      <ShortName>Variable Interest Entities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2166116 - Disclosure - Supplemental Cash Flow Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/SupplementalCashFlowInformation</Role>
      <ShortName>Supplemental Cash Flow Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2169117 - Disclosure - Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ShareholdersEquity</Role>
      <ShortName>Shareholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2173118 - Disclosure - Warrants</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/Warrants</Role>
      <ShortName>Warrants</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2175119 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2204201 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/SummaryofSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Revenue Recognition (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/RevenueRecognitionTables</Role>
      <ShortName>Revenue Recognition (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/RevenueRecognition</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2313302 - Disclosure - Acquisitions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/AcquisitionsTables</Role>
      <ShortName>Acquisitions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/Acquisitions</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2317303 - Disclosure - Goodwill and Intangible Assets, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/GoodwillandIntangibleAssetsNetTables</Role>
      <ShortName>Goodwill and Intangible Assets, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/GoodwillandIntangibleAssetsNet</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2323304 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/FairValueMeasurements</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2329305 - Disclosure - Balance Sheet Components (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/BalanceSheetComponentsTables</Role>
      <ShortName>Balance Sheet Components (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/BalanceSheetComponents</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2333306 - Disclosure - Derivative Financial Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/DerivativeFinancialInstrumentsTables</Role>
      <ShortName>Derivative Financial Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/DerivativeFinancialInstruments</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2338307 - Disclosure - Commitment and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/CommitmentandContingenciesTables</Role>
      <ShortName>Commitment and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/CommitmentandContingencies</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2344308 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/StockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/StockBasedCompensation</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2352309 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/EarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/EarningsPerShare</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2356310 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/IncomeTaxes</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2364311 - Disclosure - Variable Interest Entities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/VariableInterestEntitiesTables</Role>
      <ShortName>Variable Interest Entities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/VariableInterestEntities</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2367312 - Disclosure - Supplemental Cash Flow Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/SupplementalCashFlowInformationTables</Role>
      <ShortName>Supplemental Cash Flow Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/SupplementalCashFlowInformation</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2370313 - Disclosure - Shareholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ShareholdersEquityTables</Role>
      <ShortName>Shareholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/ShareholdersEquity</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2402401 - Disclosure - Organization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/OrganizationDetails</Role>
      <ShortName>Organization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/Organization</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Summary of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/SummaryofSignificantAccountingPoliciesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/SummaryofSignificantAccountingPoliciesPolicies</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Revenue Recognition - Disaggregation of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/RevenueRecognitionDisaggregationofRevenueDetails</Role>
      <ShortName>Revenue Recognition - Disaggregation of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2409404 - Disclosure - Revenue Recognition - Summary of Contract Balances (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/RevenueRecognitionSummaryofContractBalancesDetails</Role>
      <ShortName>Revenue Recognition - Summary of Contract Balances (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2410405 - Disclosure - Revenue Recognition - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/RevenueRecognitionNarrativeDetails</Role>
      <ShortName>Revenue Recognition - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2411406 - Disclosure - Revenue Recognition - Capitalized Service Contract Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/RevenueRecognitionCapitalizedServiceContractCostsDetails</Role>
      <ShortName>Revenue Recognition - Capitalized Service Contract Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2414407 - Disclosure - Acquisitions - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/AcquisitionsNarrativeDetails</Role>
      <ShortName>Acquisitions - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2415408 - Disclosure - Acquisitions - Fair Value of Assets Acquired and Liabilities Assumed (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/AcquisitionsFairValueofAssetsAcquiredandLiabilitiesAssumedDetails</Role>
      <ShortName>Acquisitions - Fair Value of Assets Acquired and Liabilities Assumed (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2418409 - Disclosure - Goodwill and Intangible Assets, Net - Schedule of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/GoodwillandIntangibleAssetsNetScheduleofGoodwillDetails</Role>
      <ShortName>Goodwill and Intangible Assets, Net - Schedule of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2419410 - Disclosure - Goodwill and Intangible Assets, Net - Schedule of Intangible Assets, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/GoodwillandIntangibleAssetsNetScheduleofIntangibleAssetsNetDetails</Role>
      <ShortName>Goodwill and Intangible Assets, Net - Schedule of Intangible Assets, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2420411 - Disclosure - Goodwill and Intangible Assets, Net - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/GoodwillandIntangibleAssetsNetNarrativeDetails</Role>
      <ShortName>Goodwill and Intangible Assets, Net - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2421412 - Disclosure - Goodwill and Intangible Assets, Net - Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/GoodwillandIntangibleAssetsNetScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseDetails</Role>
      <ShortName>Goodwill and Intangible Assets, Net - Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2424413 - Disclosure - Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/FairValueMeasurementsSummaryofFinancialAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetail</Role>
      <ShortName>Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2425414 - Disclosure - Fair Value Measurements - Schedule of Fair Value Measurements Inputs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/FairValueMeasurementsScheduleofFairValueMeasurementsInputsDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Fair Value Measurements Inputs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2426415 - Disclosure - Fair Value Measurements - Schedule of Changes in Fair Value of Derivative Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/FairValueMeasurementsScheduleofChangesinFairValueofDerivativeLiabilitiesDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Changes in Fair Value of Derivative Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2427416 - Disclosure - Fair Value Measurements - Schedule of Fair Value Changes by Income Statement Location (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/FairValueMeasurementsScheduleofFairValueChangesbyIncomeStatementLocationDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Fair Value Changes by Income Statement Location (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2430417 - Disclosure - Balance Sheet Components - Schedule of Property and Equipment, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/BalanceSheetComponentsScheduleofPropertyandEquipmentNetDetails</Role>
      <ShortName>Balance Sheet Components - Schedule of Property and Equipment, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2431418 - Disclosure - Balance Sheet Components - Schedule of Accrued Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/BalanceSheetComponentsScheduleofAccruedExpensesDetails</Role>
      <ShortName>Balance Sheet Components - Schedule of Accrued Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>2434419 - Disclosure - Derivative Financial Instruments - Schedule of Location and Amounts and Derivative Instruments Gains and Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/DerivativeFinancialInstrumentsScheduleofLocationandAmountsandDerivativeInstrumentsGainsandLossesDetails</Role>
      <ShortName>Derivative Financial Instruments - Schedule of Location and Amounts and Derivative Instruments Gains and Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>2436420 - Disclosure - Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/DebtDetails</Role>
      <ShortName>Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/Debt</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>2439421 - Disclosure - Commitment and Contingencies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/CommitmentandContingenciesNarrativeDetails</Role>
      <ShortName>Commitment and Contingencies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>2440422 - Disclosure - Commitment and Contingencies - Components of Lease Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/CommitmentandContingenciesComponentsofLeaseExpenseDetails</Role>
      <ShortName>Commitment and Contingencies - Components of Lease Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>2441423 - Disclosure - Commitment and Contingencies - Other Information Related to Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/CommitmentandContingenciesOtherInformationRelatedtoLeasesDetails</Role>
      <ShortName>Commitment and Contingencies - Other Information Related to Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>2442424 - Disclosure - Commitment and Contingencies - Maturity of Operating Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/CommitmentandContingenciesMaturityofOperatingLeasesDetails</Role>
      <ShortName>Commitment and Contingencies - Maturity of Operating Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>2445425 - Disclosure - Stock-Based Compensation - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/StockBasedCompensationNarrativeDetails</Role>
      <ShortName>Stock-Based Compensation - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>2446426 - Disclosure - Stock-Based Compensation - Stock-based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/StockBasedCompensationStockbasedCompensationExpenseDetails</Role>
      <ShortName>Stock-Based Compensation - Stock-based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>2447427 - Disclosure - Stock-Based Compensation - Total Stock Based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/StockBasedCompensationTotalStockBasedCompensationExpenseDetails</Role>
      <ShortName>Stock-Based Compensation - Total Stock Based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>2448428 - Disclosure - Stock-Based Compensation - Fair Value Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/StockBasedCompensationFairValueAssumptionsDetails</Role>
      <ShortName>Stock-Based Compensation - Fair Value Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>2449429 - Disclosure - Stock-Based Compensation - Activities of RSUs and SARs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/StockBasedCompensationActivitiesofRSUsandSARsDetails</Role>
      <ShortName>Stock-Based Compensation - Activities of RSUs and SARs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>2450430 - Disclosure - Stock-Based Compensation - Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/StockBasedCompensationOptionActivityDetails</Role>
      <ShortName>Stock-Based Compensation - Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>2453431 - Disclosure - Earnings Per Share - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/EarningsPerShareNarrativeDetails</Role>
      <ShortName>Earnings Per Share - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>2454432 - Disclosure - Earnings Per Share - Computation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/EarningsPerShareComputationDetails</Role>
      <ShortName>Earnings Per Share - Computation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>2457433 - Disclosure - Income Taxes - Schedule of Components of Income Tax Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/IncomeTaxesScheduleofComponentsofIncomeTaxExpenseDetails</Role>
      <ShortName>Income Taxes - Schedule of Components of Income Tax Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>2458434 - Disclosure - Income Taxes - Schedule of Effective Income Tax Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/IncomeTaxesScheduleofEffectiveIncomeTaxRateDetails</Role>
      <ShortName>Income Taxes - Schedule of Effective Income Tax Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>2459435 - Disclosure - Income Taxes - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>2460436 - Disclosure - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/IncomeTaxesScheduleofDeferredTaxAssetsandLiabilitiesDetails</Role>
      <ShortName>Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>2462437 - Disclosure - Related Party Transactions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/RelatedPartyTransactionsDetails</Role>
      <ShortName>Related Party Transactions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/RelatedPartyTransactions</ParentRole>
      <Position>78</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>2465438 - Disclosure - Variable Interest Entities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/VariableInterestEntitiesDetails</Role>
      <ShortName>Variable Interest Entities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/VariableInterestEntitiesTables</ParentRole>
      <Position>79</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>2468439 - Disclosure - Supplemental Cash Flow Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/SupplementalCashFlowInformationDetails</Role>
      <ShortName>Supplemental Cash Flow Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/SupplementalCashFlowInformationTables</ParentRole>
      <Position>80</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>2471440 - Disclosure - Shareholders' Equity - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ShareholdersEquityNarrativeDetail</Role>
      <ShortName>Shareholders' Equity - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>2472441 - Disclosure - Shareholders' Equity - Stock by Class (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/ShareholdersEquityStockbyClassDetails</Role>
      <ShortName>Shareholders' Equity - Stock by Class (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>2474442 - Disclosure - Warrants (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/WarrantsDetails</Role>
      <ShortName>Warrants (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/Warrants</ParentRole>
      <Position>83</Position>
    </Report>
    <Report instance="mktw-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>2476443 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marketwise.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marketwise.com/role/SubsequentEvents</ParentRole>
      <Position>84</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-K" original="mktw-20211231.htm">mktw-20211231.htm</File>
    <File>mktw-20211231.xsd</File>
    <File>mktw-20211231_cal.xml</File>
    <File>mktw-20211231_def.xml</File>
    <File>mktw-20211231_lab.xml</File>
    <File>mktw-20211231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>mktw-20211231_g1.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="1012">http://fasb.org/us-gaap/2021-01-31</BaseTaxonomy>
    <BaseTaxonomy items="41">http://xbrl.sec.gov/dei/2021q4</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
