<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>343</ContextCount>
  <ElementCount>427</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>76</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>14</UnitCount>
  <MyReports>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/CondensedConsolidatedBalanceSheets</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001501 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/CondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncomeLoss</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1004000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/CondensedConsolidatedStatementsOfEquity</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1004501 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/CondensedConsolidatedStatementsOfEquityParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1005000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/CondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Basis of presentation and summary of significant accounting policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Basis of presentation and summary of significant accounting policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - Revenues</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/Revenues</Role>
      <ShortName>Revenues</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2103100 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Accounts receivable, net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/AccountsReceivableNet</Role>
      <ShortName>Accounts receivable, net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - Acquisitions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/Acquisitions</Role>
      <ShortName>Acquisitions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Goodwill &amp; Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/GoodwillIntangibleAssets</Role>
      <ShortName>Goodwill &amp; Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Integration and reorganization costs and impairments of property, plant and equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IntegrationAndReorganizationCostsAndImpairmentsOfPropertyPlantAndEquipment</Role>
      <ShortName>Integration and reorganization costs and impairments of property, plant and equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Pensions and other postretirement benefit plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/PensionsAndOtherPostretirementBenefitPlans</Role>
      <ShortName>Pensions and other postretirement benefit plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Income taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IncomeTaxes</Role>
      <ShortName>Income taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2111100 - Disclosure - Supplemental equity information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformation</Role>
      <ShortName>Supplemental equity information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - Fair value measurement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/FairValueMeasurement</Role>
      <ShortName>Fair value measurement</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Commitments, contingencies and other matters</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/CommitmentsContingenciesAndOtherMatters</Role>
      <ShortName>Commitments, contingencies and other matters</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - Segment reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SegmentReporting</Role>
      <ShortName>Segment reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2115100 - Disclosure - Related party transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/RelatedPartyTransactions</Role>
      <ShortName>Related party transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - Subsequent events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2201201 - Disclosure - Basis of presentation and summary of significant accounting policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Basis of presentation and summary of significant accounting policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2301302 - Disclosure - Basis of presentation and summary of significant accounting policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Basis of presentation and summary of significant accounting policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2302301 - Disclosure - Revenues (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/RevenuesTables</Role>
      <ShortName>Revenues (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/Revenues</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/Leases</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - Accounts receivable, net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/AccountsReceivableNetTables</Role>
      <ShortName>Accounts receivable, net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/AccountsReceivableNet</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2305301 - Disclosure - Acquisitions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/AcquisitionsTables</Role>
      <ShortName>Acquisitions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/Acquisitions</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Goodwill &amp; Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/GoodwillIntangibleAssetsTables</Role>
      <ShortName>Goodwill &amp; Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/GoodwillIntangibleAssets</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Integration and reorganization costs and impairments of property, plant and equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IntegrationAndReorganizationCostsAndImpairmentsOfPropertyPlantAndEquipmentTables</Role>
      <ShortName>Integration and reorganization costs and impairments of property, plant and equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/IntegrationAndReorganizationCostsAndImpairmentsOfPropertyPlantAndEquipment</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2309301 - Disclosure - Pensions and other postretirement benefit plans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/PensionsAndOtherPostretirementBenefitPlansTables</Role>
      <ShortName>Pensions and other postretirement benefit plans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/PensionsAndOtherPostretirementBenefitPlans</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - Income taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IncomeTaxesTables</Role>
      <ShortName>Income taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/IncomeTaxes</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2311301 - Disclosure - Supplemental equity information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformationTables</Role>
      <ShortName>Supplemental equity information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/SupplementalEquityInformation</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2314301 - Disclosure - Segment reporting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SegmentReportingTables</Role>
      <ShortName>Segment reporting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/SegmentReporting</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2315301 - Disclosure - Related party transactions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/RelatedPartyTransactionsTables</Role>
      <ShortName>Related party transactions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.gannett.com/role/RelatedPartyTransactions</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2401403 - Disclosure - Basis of presentation and summary of significant accounting policies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>Basis of presentation and summary of significant accounting policies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.gannett.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2401404 - Disclosure - Basis of presentation and summary of significant accounting policies - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesScheduleOfCashCashEquivalentsAndRestrictedCashDetails</Role>
      <ShortName>Basis of presentation and summary of significant accounting policies - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2402402 - Disclosure - Revenues - Disaggregation of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/RevenuesDisaggregationOfRevenueDetails</Role>
      <ShortName>Revenues - Disaggregation of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2402403 - Disclosure - Revenues - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/RevenuesNarrativeDetails</Role>
      <ShortName>Revenues - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2402404 - Disclosure - Revenues - Deferred Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/RevenuesDeferredRevenueDetails</Role>
      <ShortName>Revenues - Deferred Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2403402 - Disclosure - Leases - Narratives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/LeasesNarrativesDetails</Role>
      <ShortName>Leases - Narratives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2403403 - Disclosure - Leases - Components of Lease Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/LeasesComponentsOfLeaseExpenseDetails</Role>
      <ShortName>Leases - Components of Lease Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2403404 - Disclosure - Leases - Future Minimum Lease Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/LeasesFutureMinimumLeasePaymentsDetails</Role>
      <ShortName>Leases - Future Minimum Lease Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2403405 - Disclosure - Leases - Other Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/LeasesOtherInformationDetails</Role>
      <ShortName>Leases - Other Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - Accounts receivable, net - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/AccountsReceivableNetNarrativeDetails</Role>
      <ShortName>Accounts receivable, net - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2404403 - Disclosure - Accounts receivable, net - Allowance for doubtful accounts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/AccountsReceivableNetAllowanceForDoubtfulAccountsDetails</Role>
      <ShortName>Accounts receivable, net - Allowance for doubtful accounts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Acquisitions - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/AcquisitionsNarrativeDetails</Role>
      <ShortName>Acquisitions - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2405403 - Disclosure - Acquisitions - Proforma (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/AcquisitionsProformaDetails</Role>
      <ShortName>Acquisitions - Proforma (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - Goodwill &amp; Intangible Assets - Schedule of Intangible Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/GoodwillIntangibleAssetsScheduleOfIntangibleAssetsDetail</Role>
      <ShortName>Goodwill &amp; Intangible Assets - Schedule of Intangible Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2406403 - Disclosure - Goodwill and other intangible assets - Change in Goodwill (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/GoodwillAndOtherIntangibleAssetsChangeInGoodwillDetail</Role>
      <ShortName>Goodwill and other intangible assets - Change in Goodwill (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2406404 - Disclosure - Goodwill and other intangible assets - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetail</Role>
      <ShortName>Goodwill and other intangible assets - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Integration and reorganization costs and impairments of property, plant and equipment - Severance Related Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IntegrationAndReorganizationCostsAndImpairmentsOfPropertyPlantAndEquipmentSeveranceRelatedExpensesDetails</Role>
      <ShortName>Integration and reorganization costs and impairments of property, plant and equipment - Severance Related Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Integration and reorganization costs and impairments of property, plant and equipment - Restructuring Reserve (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IntegrationAndReorganizationCostsAndImpairmentsOfPropertyPlantAndEquipmentRestructuringReserveDetails</Role>
      <ShortName>Integration and reorganization costs and impairments of property, plant and equipment - Restructuring Reserve (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2407404 - Disclosure - Integration and reorganization costs and impairments of property, plant and equipment - Facility Consolidation Charges and Accelerated Depreciation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IntegrationAndReorganizationCostsAndImpairmentsOfPropertyPlantAndEquipmentFacilityConsolidationChargesAndAcceleratedDepreciationDetails</Role>
      <ShortName>Integration and reorganization costs and impairments of property, plant and equipment - Facility Consolidation Charges and Accelerated Depreciation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2407405 - Disclosure - Integration and reorganization costs and impairments of property, plant and equipment - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IntegrationAndReorganizationCostsAndImpairmentsOfPropertyPlantAndEquipmentNarrativeDetails</Role>
      <ShortName>Integration and reorganization costs and impairments of property, plant and equipment - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.gannett.com/role/IntegrationAndReorganizationCostsAndImpairmentsOfPropertyPlantAndEquipmentTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2408401 - Disclosure - Debt - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/DebtNarrativeDetails</Role>
      <ShortName>Debt - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2409402 - Disclosure - Pensions and other postretirement benefit plans - Retirement Plan Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/PensionsAndOtherPostretirementBenefitPlansRetirementPlanCostsDetails</Role>
      <ShortName>Pensions and other postretirement benefit plans - Retirement Plan Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2409403 - Disclosure - Pensions and other postretirement benefit plans - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/PensionsAndOtherPostretirementBenefitPlansNarrativeDetails</Role>
      <ShortName>Pensions and other postretirement benefit plans - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - Income taxes - Pre-tax Net Loss and Income Tax (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IncomeTaxesPreTaxNetLossAndIncomeTaxDetails</Role>
      <ShortName>Income taxes - Pre-tax Net Loss and Income Tax (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>2410403 - Disclosure - Income taxes - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income taxes - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>2411402 - Disclosure - Supplemental equity information - Loss Per Share (Basic and Diluted) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformationLossPerShareBasicAndDilutedDetail</Role>
      <ShortName>Supplemental equity information - Loss Per Share (Basic and Diluted) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>2411403 - Disclosure - Supplemental equity information - Computation of Diluted Income Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformationComputationOfDilutedIncomePerShareDetail</Role>
      <ShortName>Supplemental equity information - Computation of Diluted Income Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>2411404 - Disclosure - Supplemental equity information - Narrative (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformationNarrativeDetail</Role>
      <ShortName>Supplemental equity information - Narrative (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>2411405 - Disclosure - Supplemental equity information - Summary of Stock-Option Awards (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformationSummaryOfStockOptionAwardsDetail</Role>
      <ShortName>Supplemental equity information - Summary of Stock-Option Awards (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>2411406 - Disclosure - Supplemental equity information - Restricted Stock Grants (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformationRestrictedStockGrantsDetails</Role>
      <ShortName>Supplemental equity information - Restricted Stock Grants (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>2411407 - Disclosure - Supplemental equity information - Rights Agreement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformationRightsAgreementDetails</Role>
      <ShortName>Supplemental equity information - Rights Agreement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>2411408 - Disclosure - Supplemental equity information - Accumulated Other Comprehensive Income (Loss) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformationAccumulatedOtherComprehensiveIncomeLossDetails</Role>
      <ShortName>Supplemental equity information - Accumulated Other Comprehensive Income (Loss) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>2411409 - Disclosure - Supplemental equity information - Reclassifications of Accumulated Other Comprehensive Loss Related to Postretirement Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SupplementalEquityInformationReclassificationsOfAccumulatedOtherComprehensiveLossRelatedToPostretirementPlansDetails</Role>
      <ShortName>Supplemental equity information - Reclassifications of Accumulated Other Comprehensive Loss Related to Postretirement Plans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>2412401 - Disclosure - Fair value measurement - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/FairValueMeasurementNarrativeDetails</Role>
      <ShortName>Fair value measurement - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>2414402 - Disclosure - Segment reporting - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SegmentReportingNarrativeDetails</Role>
      <ShortName>Segment reporting - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>2414403 - Disclosure - Segment reporting -Segment Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SegmentReportingSegmentInformationDetails</Role>
      <ShortName>Segment reporting -Segment Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>2414404 - Disclosure - Segment reporting - Reconciliation of EBITDA to Operating Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SegmentReportingReconciliationOfEbitdaToOperatingIncomeDetails</Role>
      <ShortName>Segment reporting - Reconciliation of EBITDA to Operating Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>2415402 - Disclosure - Related party transactions - Management and Incentive Fees (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/RelatedPartyTransactionsManagementAndIncentiveFeesDetails</Role>
      <ShortName>Related party transactions - Management and Incentive Fees (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>2416401 - Disclosure - Subsequent events - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.gannett.com/role/SubsequentEventsNarrativeDetails</Role>
      <ShortName>Subsequent events - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="gci-20200930x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9999.htm</HtmlFileName>
      <LongName>Uncategorized Items - gci-20200930x10q.htm</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/role/uncategorizedFacts</Role>
      <ShortName>Uncategorized Items - gci-20200930x10q.htm</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-Q" original="gci-20200930x10q.htm">gci-20200930x10q.htm</File>
    <File>gci-20200930.xsd</File>
    <File>gci-20200930_cal.xml</File>
    <File>gci-20200930_def.xml</File>
    <File>gci-20200930_lab.xml</File>
    <File>gci-20200930_pre.xml</File>
    <File>gci-20200930xex31x1.htm</File>
    <File>gci-20200930xex31x2.htm</File>
    <File>gci-20200930xex32x1.htm</File>
    <File>gci-20200930xex32x2.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/country/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2020-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
