<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>557</ContextCount>
  <ElementCount>607</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>146</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>11</UnitCount>
  <MyReports>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000010001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>000020002 - Document - Audit Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/AuditInformation</Role>
      <ShortName>Audit Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>100010003 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Uncategorized</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>100020004 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>100030005 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ConsolidatedStatementsofOperations</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>100050007 - Statement - Consolidated Statements of Comprehensive Loss</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ConsolidatedStatementsofComprehensiveLoss</Role>
      <ShortName>Consolidated Statements of Comprehensive Loss</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>100060008 - Statement - Consolidated Statements of Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ConsolidatedStatementsofShareholdersEquity</Role>
      <ShortName>Consolidated Statements of Shareholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>100070009 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ConsolidatedStatementsofCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>210011001 - Disclosure - Organization and Description of Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/OrganizationandDescriptionofBusiness</Role>
      <ShortName>Organization and Description of Business</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>210021002 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SummaryofSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>210071003 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>210131004 - Disclosure - Cash and Cash Equivalents, Investments and Restricted Cash</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/CashandCashEquivalentsInvestmentsandRestrictedCash</Role>
      <ShortName>Cash and Cash Equivalents, Investments and Restricted Cash</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>210171005 - Disclosure - Inventory</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/Inventory</Role>
      <ShortName>Inventory</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>210201006 - Disclosure - Contract Balances</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ContractBalances</Role>
      <ShortName>Contract Balances</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>210241007 - Disclosure - Contract Cost Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ContractCostAssets</Role>
      <ShortName>Contract Cost Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>210261008 - Disclosure - Property and Equipment, net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/PropertyandEquipmentnet</Role>
      <ShortName>Property and Equipment, net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>210301009 - Disclosure - Acquisition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/Acquisition</Role>
      <ShortName>Acquisition</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>210351010 - Disclosure - Goodwill and Intangible Assets, net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/GoodwillandIntangibleAssetsnet</Role>
      <ShortName>Goodwill and Intangible Assets, net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>210411011 - Disclosure - Accrued Expenses and Other Current Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/AccruedExpensesandOtherCurrentLiabilities</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>210441012 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>210501013 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>210701014 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>210771015 - Disclosure - Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareholdersEquity</Role>
      <ShortName>Shareholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>210821016 - Disclosure - Share-Based Awards</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareBasedAwards</Role>
      <ShortName>Share-Based Awards</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>210891017 - Disclosure - Net Loss Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/NetLossPerShare</Role>
      <ShortName>Net Loss Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>210921018 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>210961019 - Disclosure - Self-Insurance</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SelfInsurance</Role>
      <ShortName>Self-Insurance</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>210981020 - Disclosure - Employee Benefit Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/EmployeeBenefitPlan</Role>
      <ShortName>Employee Benefit Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>211001021 - Disclosure - Segment Information and Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SegmentInformationandRevenue</Role>
      <ShortName>Segment Information and Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>211051022 - Disclosure - Restructuring and Zillow Offers Wind Down</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/RestructuringandZillowOffersWindDown</Role>
      <ShortName>Restructuring and Zillow Offers Wind Down</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>211101023 - Disclosure - Subsequent Event</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SubsequentEvent</Role>
      <ShortName>Subsequent Event</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>220042001 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SummaryofSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>230033001 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SummaryofSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>230083002 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/FairValueMeasurements</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>230143003 - Disclosure - Cash and Cash Equivalents, Investments and Restricted Cash (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/CashandCashEquivalentsInvestmentsandRestrictedCashTables</Role>
      <ShortName>Cash and Cash Equivalents, Investments and Restricted Cash (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/CashandCashEquivalentsInvestmentsandRestrictedCash</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>230183004 - Disclosure - Inventory (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/InventoryTables</Role>
      <ShortName>Inventory (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/Inventory</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>230213005 - Disclosure - Contract Balances (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ContractBalancesTables</Role>
      <ShortName>Contract Balances (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/ContractBalances</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>230273006 - Disclosure - Property and Equipment, net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/PropertyandEquipmentnetTables</Role>
      <ShortName>Property and Equipment, net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/PropertyandEquipmentnet</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>230313007 - Disclosure - Acquisition (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/AcquisitionTables</Role>
      <ShortName>Acquisition (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/Acquisition</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>230363008 - Disclosure - Goodwill and Intangible Assets, net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/GoodwillandIntangibleAssetsnetTables</Role>
      <ShortName>Goodwill and Intangible Assets, net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/GoodwillandIntangibleAssetsnet</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>230423009 - Disclosure - Accrued Expenses and Other Current Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/AccruedExpensesandOtherCurrentLiabilitiesTables</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/AccruedExpensesandOtherCurrentLiabilities</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>230453010 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/Leases</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>230513011 - Disclosure - Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtTables</Role>
      <ShortName>Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/Debt</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>230713012 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/IncomeTaxes</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>230783013 - Disclosure - Shareholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareholdersEquityTables</Role>
      <ShortName>Shareholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/ShareholdersEquity</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>230833014 - Disclosure - Share-Based Awards (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareBasedAwardsTables</Role>
      <ShortName>Share-Based Awards (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/ShareBasedAwards</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>230903015 - Disclosure - Net Loss Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/NetLossPerShareTables</Role>
      <ShortName>Net Loss Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/NetLossPerShare</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>230933016 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/CommitmentsandContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/CommitmentsandContingencies</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>231013017 - Disclosure - Segment Information and Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SegmentInformationandRevenueTables</Role>
      <ShortName>Segment Information and Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/SegmentInformationandRevenue</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>231063018 - Disclosure - Restructuring and Zillow Offers Wind Down (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/RestructuringandZillowOffersWindDownTables</Role>
      <ShortName>Restructuring and Zillow Offers Wind Down (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/RestructuringandZillowOffersWindDown</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>240054001 - Disclosure - Summary of Significant Accounting Policies - Reclassifications (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SummaryofSignificantAccountingPoliciesReclassificationsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Reclassifications (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>240064002 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SummaryofSignificantAccountingPoliciesAdditionalInformationDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>240094003 - Disclosure - Fair Value Measurements - Range and Weighted Average Pull-Through Rates (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/FairValueMeasurementsRangeandWeightedAveragePullThroughRatesDetails</Role>
      <ShortName>Fair Value Measurements - Range and Weighted Average Pull-Through Rates (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>240104004 - Disclosure - Fair Value Measurements - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/FairValueMeasurementsAdditionalInformationDetail</Role>
      <ShortName>Fair Value Measurements - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>240114005 - Disclosure - Fair Value Measurements - Fair Value of Cash Equivalents and Investments (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/FairValueMeasurementsFairValueofCashEquivalentsandInvestmentsDetail</Role>
      <ShortName>Fair Value Measurements - Fair Value of Cash Equivalents and Investments (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>240124006 - Disclosure - Fair Value Measurements - Changes in IRLC's (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/FairValueMeasurementsChangesinIRLCsDetails</Role>
      <ShortName>Fair Value Measurements - Changes in IRLC's (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>240154007 - Disclosure - Cash and Cash Equivalents, Investments and Restricted Cash - Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Market Value of Cash and Cash Equivalents and Available-for-Sale Investments (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/CashandCashEquivalentsInvestmentsandRestrictedCashAmortizedCostGrossUnrealizedGainsandLossesandEstimatedFairMarketValueofCashandCashEquivalentsandAvailableforSaleInvestmentsDetail</Role>
      <ShortName>Cash and Cash Equivalents, Investments and Restricted Cash - Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Market Value of Cash and Cash Equivalents and Available-for-Sale Investments (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>240164008 - Disclosure - Cash and Cash Equivalents, Investments and Restricted Cash - Available-for-sale Investments By Contractual Maturity Date (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/CashandCashEquivalentsInvestmentsandRestrictedCashAvailableforsaleInvestmentsByContractualMaturityDateDetails</Role>
      <ShortName>Cash and Cash Equivalents, Investments and Restricted Cash - Available-for-sale Investments By Contractual Maturity Date (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>240194009 - Disclosure - Inventory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/InventoryDetails</Role>
      <ShortName>Inventory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/InventoryTables</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>240224010 - Disclosure - Contract Balances (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ContractBalancesDetails</Role>
      <ShortName>Contract Balances (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/ContractBalancesTables</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>240234011 - Disclosure - Contract Balances - Summary of Changes in Allowance for Doubtful Accounts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ContractBalancesSummaryofChangesinAllowanceforDoubtfulAccountsDetails</Role>
      <ShortName>Contract Balances - Summary of Changes in Allowance for Doubtful Accounts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>240254012 - Disclosure - Contract Cost Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ContractCostAssetsDetails</Role>
      <ShortName>Contract Cost Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.zillowgroup.com/role/ContractCostAssets</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>240284013 - Disclosure - Property and Equipment, net - Detail of Property and Equipment (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/PropertyandEquipmentnetDetailofPropertyandEquipmentDetail</Role>
      <ShortName>Property and Equipment, net - Detail of Property and Equipment (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>240294014 - Disclosure - Property and Equipment, net - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/PropertyandEquipmentnetAdditionalInformationDetail</Role>
      <ShortName>Property and Equipment, net - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>240324015 - Disclosure - Acquisition - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/AcquisitionNarrativeDetail</Role>
      <ShortName>Acquisition - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>240334016 - Disclosure - Acquisition - Preliminary Purchase Price (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/AcquisitionPreliminaryPurchasePriceDetails</Role>
      <ShortName>Acquisition - Preliminary Purchase Price (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>240344017 - Disclosure - Acquisition - Preliminary Estimated Fair Value and Useful Lives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/AcquisitionPreliminaryEstimatedFairValueandUsefulLivesDetails</Role>
      <ShortName>Acquisition - Preliminary Estimated Fair Value and Useful Lives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>240374018 - Disclosure - Goodwill and Intangible Assets, net - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/GoodwillandIntangibleAssetsnetAdditionalInformationDetail</Role>
      <ShortName>Goodwill and Intangible Assets, net - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>240384019 - Disclosure - Goodwill and Intangible Assets, net - Goodwill Allocated to Reportable Segments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/GoodwillandIntangibleAssetsnetGoodwillAllocatedtoReportableSegmentsDetails</Role>
      <ShortName>Goodwill and Intangible Assets, net - Goodwill Allocated to Reportable Segments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>240394020 - Disclosure - Goodwill and Intangible Assets, net - Intangible Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/GoodwillandIntangibleAssetsnetIntangibleAssetsDetail</Role>
      <ShortName>Goodwill and Intangible Assets, net - Intangible Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>240404021 - Disclosure - Goodwill and Intangible Assets, net - Estimated Future Amortization Expense for Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/GoodwillandIntangibleAssetsnetEstimatedFutureAmortizationExpenseforIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Intangible Assets, net - Estimated Future Amortization Expense for Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>240434022 - Disclosure - Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/AccruedExpensesandOtherCurrentLiabilitiesSummaryofAccruedExpensesandOtherCurrentLiabilitiesDetails</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>240464023 - Disclosure - Leases - Components of Lease Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/LeasesComponentsofLeaseExpenseDetails</Role>
      <ShortName>Leases - Components of Lease Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>240474024 - Disclosure - Leases - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/LeasesNarrativeDetails</Role>
      <ShortName>Leases - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>240484025 - Disclosure - Leases - Other Information Obtained (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/LeasesOtherInformationObtainedDetails</Role>
      <ShortName>Leases - Other Information Obtained (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>240494026 - Disclosure - Leases - Schedule of Maturities for Operating Lease Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/LeasesScheduleofMaturitiesforOperatingLeaseLiabilitiesDetails</Role>
      <ShortName>Leases - Schedule of Maturities for Operating Lease Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>240524027 - Disclosure - Debt - Schedule of Carrying Value of Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtScheduleofCarryingValueofDebtDetails</Role>
      <ShortName>Debt - Schedule of Carrying Value of Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>240534028 - Disclosure - Debt - Home Segment, Variable Interest Entities Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtHomeSegmentVariableInterestEntitiesNarrativeDetails</Role>
      <ShortName>Debt - Home Segment, Variable Interest Entities Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>240544029 - Disclosure - Debt - Schedule of Credit Facilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtScheduleofCreditFacilitiesDetails</Role>
      <ShortName>Debt - Schedule of Credit Facilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>240554030 - Disclosure - Debt - Home Segment, Credit Facilities Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtHomeSegmentCreditFacilitiesNarrativeDetails</Role>
      <ShortName>Debt - Home Segment, Credit Facilities Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>240564031 - Disclosure - Debt - Home Segment, Securitization Transactions Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtHomeSegmentSecuritizationTransactionsNarrativeDetails</Role>
      <ShortName>Debt - Home Segment, Securitization Transactions Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>240574032 - Disclosure - Debt - Summary of Variable Funding Lines (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtSummaryofVariableFundingLinesDetails</Role>
      <ShortName>Debt - Summary of Variable Funding Lines (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>240584033 - Disclosure - Debt - Summary of Term Loan Details (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtSummaryofTermLoanDetailsDetails</Role>
      <ShortName>Debt - Summary of Term Loan Details (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>240594034 - Disclosure - Debt - Mortgages Segment, Schedule of Warehouse Lines of Credit (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtMortgagesSegmentScheduleofWarehouseLinesofCreditDetails</Role>
      <ShortName>Debt - Mortgages Segment, Schedule of Warehouse Lines of Credit (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>240604035 - Disclosure - Debt - Mortgages Segment, Master Repurchase Agreements Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtMortgagesSegmentMasterRepurchaseAgreementsNarrativeDetail</Role>
      <ShortName>Debt - Mortgages Segment, Master Repurchase Agreements Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>240614036 - Disclosure - Debt - Mortgages Segment, Warehouse Line of Credit Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtMortgagesSegmentWarehouseLineofCreditNarrativeDetails</Role>
      <ShortName>Debt - Mortgages Segment, Warehouse Line of Credit Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>240624037 - Disclosure - Debt - Schedule of Convertible Senior Notes (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtScheduleofConvertibleSeniorNotesDetails</Role>
      <ShortName>Debt - Schedule of Convertible Senior Notes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>240634038 - Disclosure - Debt - Convertible Senior Notes due in 2025 Narrative (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtConvertibleSeniorNotesduein2025NarrativeDetails</Role>
      <ShortName>Debt - Convertible Senior Notes due in 2025 Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>240644039 - Disclosure - Debt - Convertible Senior Notes due in 2024 and 2026 Narrative (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtConvertibleSeniorNotesduein2024and2026NarrativeDetails</Role>
      <ShortName>Debt - Convertible Senior Notes due in 2024 and 2026 Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>240654040 - Disclosure - Debt - Convertible Senior Notes due in 2023 Narrative (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtConvertibleSeniorNotesduein2023NarrativeDetails</Role>
      <ShortName>Debt - Convertible Senior Notes due in 2023 Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>240664041 - Disclosure - Debt - Convertible Senior Notes due in 2021 Narrative (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtConvertibleSeniorNotesduein2021NarrativeDetails</Role>
      <ShortName>Debt - Convertible Senior Notes due in 2021 Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>240674042 - Disclosure - Debt - Summary of Conversion and Redemption (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtSummaryofConversionandRedemptionDetails</Role>
      <ShortName>Debt - Summary of Conversion and Redemption (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>240684043 - Disclosure - Debt - Summary of Convertible Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtSummaryofConvertibleDebtDetails</Role>
      <ShortName>Debt - Summary of Convertible Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>240694044 - Disclosure - Debt - Capped Call Confirmations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/DebtCappedCallConfirmationsDetails</Role>
      <ShortName>Debt - Capped Call Confirmations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>240724045 - Disclosure - Income Taxes - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/IncomeTaxesAdditionalInformationDetail</Role>
      <ShortName>Income Taxes - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>240734046 - Disclosure - Income Taxes - Components of Income Tax (Benefit) Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/IncomeTaxesComponentsofIncomeTaxBenefitExpenseDetails</Role>
      <ShortName>Income Taxes - Components of Income Tax (Benefit) Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>240744047 - Disclosure - Income Taxes - Reconciliation of Federal Statutory Rate and Effective Tax Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/IncomeTaxesReconciliationofFederalStatutoryRateandEffectiveTaxRateDetails</Role>
      <ShortName>Income Taxes - Reconciliation of Federal Statutory Rate and Effective Tax Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>240754048 - Disclosure - Income Taxes - Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/IncomeTaxesDeferredTaxAssetsandLiabilitiesDetails</Role>
      <ShortName>Income Taxes - Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>240764049 - Disclosure - Income Taxes - Changes in Unrecognized Tax Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/IncomeTaxesChangesinUnrecognizedTaxBenefitsDetails</Role>
      <ShortName>Income Taxes - Changes in Unrecognized Tax Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>99</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>240794050 - Disclosure - Shareholders' Equity - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareholdersEquityAdditionalInformationDetail</Role>
      <ShortName>Shareholders' Equity - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>100</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>240804051 - Disclosure - Shareholders' Equity - Summary of Equity Distribution (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareholdersEquitySummaryofEquityDistributionDetails</Role>
      <ShortName>Shareholders' Equity - Summary of Equity Distribution (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>101</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>240814052 - Disclosure - Shareholders' Equity - Summary of Stock Repurchase Program (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareholdersEquitySummaryofStockRepurchaseProgramDetails</Role>
      <ShortName>Shareholders' Equity - Summary of Stock Repurchase Program (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>102</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>240844053 - Disclosure - Share-Based Awards - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareBasedAwardsAdditionalInformationDetail</Role>
      <ShortName>Share-Based Awards - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>103</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>240854054 - Disclosure - Share-Based Awards - Summary of Option Award (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareBasedAwardsSummaryofOptionAwardDetail</Role>
      <ShortName>Share-Based Awards - Summary of Option Award (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>104</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>240864055 - Disclosure - Share-Based Awards - Fair Value of Options Granted, Estimated at Date of Grant Using Black Scholes Merton Option Pricing Model (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareBasedAwardsFairValueofOptionsGrantedEstimatedatDateofGrantUsingBlackScholesMertonOptionPricingModelDetail</Role>
      <ShortName>Share-Based Awards - Fair Value of Options Granted, Estimated at Date of Grant Using Black Scholes Merton Option Pricing Model (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>105</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>240874056 - Disclosure - Share-Based Awards - Summary of Restricted Stock Units Activity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareBasedAwardsSummaryofRestrictedStockUnitsActivityDetail</Role>
      <ShortName>Share-Based Awards - Summary of Restricted Stock Units Activity (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>106</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>240884057 - Disclosure - Share-Based Awards - Effects of Share Based Compensation in Consolidated Statements of Operations (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/ShareBasedAwardsEffectsofShareBasedCompensationinConsolidatedStatementsofOperationsDetail</Role>
      <ShortName>Share-Based Awards - Effects of Share Based Compensation in Consolidated Statements of Operations (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>107</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>240914058 - Disclosure - Net Loss Per Share - Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/NetLossPerShareAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetail</Role>
      <ShortName>Net Loss Per Share - Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>240944059 - Disclosure - Commitments and Contingencies - Purchase Commitments for Content Related to Mobile Applications and Websites (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/CommitmentsandContingenciesPurchaseCommitmentsforContentRelatedtoMobileApplicationsandWebsitesDetails</Role>
      <ShortName>Commitments and Contingencies - Purchase Commitments for Content Related to Mobile Applications and Websites (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>109</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>240954060 - Disclosure - Commitments and Contingencies - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/CommitmentsandContingenciesAdditionalInformationDetail</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>240974061 - Disclosure - Self-Insurance - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SelfInsuranceAdditionalInformationDetail</Role>
      <ShortName>Self-Insurance - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>111</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>240994062 - Disclosure - Employee Benefit Plan - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/EmployeeBenefitPlanAdditionalInformationDetail</Role>
      <ShortName>Employee Benefit Plan - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>112</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>241024063 - Disclosure - Segment Information and Revenue - Revenue Categories (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SegmentInformationandRevenueRevenueCategoriesDetail</Role>
      <ShortName>Segment Information and Revenue - Revenue Categories (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>113</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>241034064 - Disclosure - Segment Information and Revenue - Depreciation and Amortization Expense and Share-Based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SegmentInformationandRevenueDepreciationandAmortizationExpenseandShareBasedCompensationExpenseDetails</Role>
      <ShortName>Segment Information and Revenue - Depreciation and Amortization Expense and Share-Based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>114</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>241044065 - Disclosure - Segment Information and Revenue - Reconciliation of Segment Gross Profit and Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/SegmentInformationandRevenueReconciliationofSegmentGrossProfitandLossDetails</Role>
      <ShortName>Segment Information and Revenue - Reconciliation of Segment Gross Profit and Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>115</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>241074066 - Disclosure - Restructuring and Zillow Offers Wind Down - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/RestructuringandZillowOffersWindDownNarrativeDetails</Role>
      <ShortName>Restructuring and Zillow Offers Wind Down - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>116</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>241084067 - Disclosure - Restructuring and Zillow Offers Wind Down - Charges Incurred and Expected (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/RestructuringandZillowOffersWindDownChargesIncurredandExpectedDetails</Role>
      <ShortName>Restructuring and Zillow Offers Wind Down - Charges Incurred and Expected (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>117</Position>
    </Report>
    <Report instance="z-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>241094068 - Disclosure - Restructuring and Zillow Offers Wind Down - Restructuring Reserve (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.zillowgroup.com/role/RestructuringandZillowOffersWindDownRestructuringReserveDetails</Role>
      <ShortName>Restructuring and Zillow Offers Wind Down - Restructuring Reserve (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>118</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="z-20211231.htm">z-20211231.htm</File>
    <File>a2021form10-kex211.htm</File>
    <File>a2021form10-kex231.htm</File>
    <File>a2021form10-kex311.htm</File>
    <File>a2021form10-kex312.htm</File>
    <File>a2021form10-kex321.htm</File>
    <File>a2021form10-kex322.htm</File>
    <File>exhibit1021.htm</File>
    <File>z-20211231.xsd</File>
    <File>z-20211231_cal.xml</File>
    <File>z-20211231_def.xml</File>
    <File>z-20211231_lab.xml</File>
    <File>z-20211231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>z-20211231_g1.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="1740">http://fasb.org/us-gaap/2021-01-31</BaseTaxonomy>
    <BaseTaxonomy items="43">http://xbrl.sec.gov/dei/2021q4</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
