<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xml:lang="en-US"
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2025"
  xmlns:ecd="http://xbrl.sec.gov/ecd/2025"
  xmlns:iso4217="http://www.xbrl.org/2003/iso4217"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="cnne-20251231.xsd" xlink:type="simple"/>
    <context id="c-1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001704720</identifier>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="c-2">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001704720</identifier>
        </entity>
        <period>
            <instant>2025-06-30</instant>
        </period>
    </context>
    <context id="c-3">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001704720</identifier>
        </entity>
        <period>
            <instant>2026-02-20</instant>
        </period>
    </context>
    <unit id="usd">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="shares">
        <measure>shares</measure>
    </unit>
    <dei:AmendmentFlag contextRef="c-1" id="f-31">true</dei:AmendmentFlag>
    <dei:AmendmentDescription contextRef="c-1" id="f-32">This Amendment No. 1 (the "Amendment") on Form 10-K/A is being filed with respect to the Registrant&#x2019;s Annual Report on Form 10-K for the fiscal year ended December 31, 2025 filed with the Securities and Exchange Commission on March 2, 2026 (the "Form 10-K"). This Amendment updates Part III in its entirety to contain the information required therein. Except for the changes to Part III and the filing of related certifications added to the list of Exhibits in Part IV, this Amendment makes no changes to the Form 10-K. This Amendment does not reflect events occurring after the filing of the Form 10-K or modify disclosures affected by subsequent events.</dei:AmendmentDescription>
    <dei:DocumentFiscalYearFocus contextRef="c-1" id="f-33">2025</dei:DocumentFiscalYearFocus>
    <dei:DocumentFiscalPeriodFocus contextRef="c-1" id="f-34">FY</dei:DocumentFiscalPeriodFocus>
    <dei:EntityCentralIndexKey contextRef="c-1" id="f-35">0001704720</dei:EntityCentralIndexKey>
    <dei:DocumentType contextRef="c-1" id="f-1">10-K/A</dei:DocumentType>
    <dei:DocumentAnnualReport contextRef="c-1" id="f-2">true</dei:DocumentAnnualReport>
    <dei:DocumentPeriodEndDate contextRef="c-1" id="f-4">2025-12-31</dei:DocumentPeriodEndDate>
    <dei:CurrentFiscalYearEndDate contextRef="c-1" id="f-3">--12-31</dei:CurrentFiscalYearEndDate>
    <dei:DocumentTransitionReport contextRef="c-1" id="f-5">false</dei:DocumentTransitionReport>
    <dei:EntityFileNumber contextRef="c-1" id="f-6">1-38300</dei:EntityFileNumber>
    <dei:EntityRegistrantName contextRef="c-1" id="f-7">CANNAE HOLDINGS, INC.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode contextRef="c-1" id="f-8">NV</dei:EntityIncorporationStateCountryCode>
    <dei:EntityTaxIdentificationNumber contextRef="c-1" id="f-9">82-1273460</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1 contextRef="c-1" id="f-10">1701 Village Center Circle,</dei:EntityAddressAddressLine1>
    <dei:EntityAddressCityOrTown contextRef="c-1" id="f-11">Las Vegas,</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince contextRef="c-1" id="f-12">NV</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode contextRef="c-1" id="f-13">89134</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode contextRef="c-1" id="f-14">702</dei:CityAreaCode>
    <dei:LocalPhoneNumber contextRef="c-1" id="f-15">323-7330</dei:LocalPhoneNumber>
    <dei:Security12bTitle contextRef="c-1" id="f-16">Cannae Common Stock, $0.0001&#160;par value</dei:Security12bTitle>
    <dei:TradingSymbol contextRef="c-1" id="f-17">CNNE</dei:TradingSymbol>
    <dei:SecurityExchangeName contextRef="c-1" id="f-18">NYSE</dei:SecurityExchangeName>
    <dei:EntityWellKnownSeasonedIssuer contextRef="c-1" id="f-19">Yes</dei:EntityWellKnownSeasonedIssuer>
    <dei:EntityVoluntaryFilers contextRef="c-1" id="f-20">No</dei:EntityVoluntaryFilers>
    <dei:EntityCurrentReportingStatus contextRef="c-1" id="f-21">Yes</dei:EntityCurrentReportingStatus>
    <dei:EntityInteractiveDataCurrent contextRef="c-1" id="f-22">Yes</dei:EntityInteractiveDataCurrent>
    <dei:EntityFilerCategory contextRef="c-1" id="f-23">Large Accelerated Filer</dei:EntityFilerCategory>
    <dei:EntitySmallBusiness contextRef="c-1" id="f-24">false</dei:EntitySmallBusiness>
    <dei:EntityEmergingGrowthCompany contextRef="c-1" id="f-25">false</dei:EntityEmergingGrowthCompany>
    <dei:IcfrAuditorAttestationFlag contextRef="c-1" id="f-26">true</dei:IcfrAuditorAttestationFlag>
    <dei:DocumentFinStmtErrorCorrectionFlag contextRef="c-1" id="f-27">false</dei:DocumentFinStmtErrorCorrectionFlag>
    <dei:EntityShellCompany contextRef="c-1" id="f-28">false</dei:EntityShellCompany>
    <dei:EntityPublicFloat contextRef="c-2" decimals="0" id="f-29" unitRef="usd">1061691612</dei:EntityPublicFloat>
    <dei:EntityCommonStockSharesOutstanding contextRef="c-3" decimals="INF" id="f-30" unitRef="shares">44220506</dei:EntityCommonStockSharesOutstanding>
    <ecd:AwardTmgMethodTextBlock contextRef="c-1" id="f-37">The Company did not award any performance-based equity awards or stock options to its named executive officers in the fiscal year ended December&#160;31, 2025. Moreover, the Company did not time the disclosure of material nonpublic information for the purpose of affecting the value of executive compensation.</ecd:AwardTmgMethodTextBlock>
    <ecd:AwardTmgMnpiDiscTextBlock contextRef="c-1" id="f-36">The Company did not award any performance-based equity awards or stock options to its named executive officers in the fiscal year ended December&#160;31, 2025. Moreover, the Company did not time the disclosure of material nonpublic information for the purpose of affecting the value of executive compensation.</ecd:AwardTmgMnpiDiscTextBlock>
    <ecd:AwardTmgPredtrmndFlag contextRef="c-1" id="f-38">false</ecd:AwardTmgPredtrmndFlag>
    <ecd:AwardTmgHowMnpiCnsdrdTextBlock contextRef="c-1" id="f-39">Moreover, the Company did not time the disclosure of material nonpublic information for the purpose of affecting the value of executive compensation.</ecd:AwardTmgHowMnpiCnsdrdTextBlock>
    <ecd:AwardTmgMnpiCnsdrdFlag contextRef="c-1" id="f-40">false</ecd:AwardTmgMnpiCnsdrdFlag>
    <ecd:MnpiDiscTimedForCompValFlag contextRef="c-1" id="f-41">false</ecd:MnpiDiscTimedForCompValFlag>
    <ecd:InsiderTrdPoliciesProcAdoptedFlag contextRef="c-1" id="f-42">true</ecd:InsiderTrdPoliciesProcAdoptedFlag>
</xbrl>
