<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.24.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>81</ContextCount>
  <ElementCount>27</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>12</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>2</UnitCount>
  <MyReports>
    <Report instance="cinf-20240319.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>995100 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/dei/role/document/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="cinf-20240319.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>995410 - Disclosure - Pay vs Performance Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/PvpDisclosure</Role>
      <ShortName>Pay vs Performance Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>2</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="DEF 14A" isProxy="true" isUsgaap="true" original="cinf-20240319.htm">cinf-20240319.htm</File>
    <File>cinf-20240319.xsd</File>
    <File>cinf-20240319_def.xml</File>
    <File>cinf-20240319_lab.xml</File>
    <File>cinf-20240319_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>cinf-20240319_g1.jpg</File>
    <File>cinf-20240319_g10.jpg</File>
    <File>cinf-20240319_g11.jpg</File>
    <File>cinf-20240319_g12.jpg</File>
    <File>cinf-20240319_g13.jpg</File>
    <File>cinf-20240319_g14.jpg</File>
    <File>cinf-20240319_g15.jpg</File>
    <File>cinf-20240319_g16.jpg</File>
    <File>cinf-20240319_g17.jpg</File>
    <File>cinf-20240319_g18.jpg</File>
    <File>cinf-20240319_g19.jpg</File>
    <File>cinf-20240319_g2.jpg</File>
    <File>cinf-20240319_g20.jpg</File>
    <File>cinf-20240319_g21.jpg</File>
    <File>cinf-20240319_g22.jpg</File>
    <File>cinf-20240319_g23.jpg</File>
    <File>cinf-20240319_g24.jpg</File>
    <File>cinf-20240319_g25.jpg</File>
    <File>cinf-20240319_g26.jpg</File>
    <File>cinf-20240319_g27.jpg</File>
    <File>cinf-20240319_g28.jpg</File>
    <File>cinf-20240319_g29.jpg</File>
    <File>cinf-20240319_g3.jpg</File>
    <File>cinf-20240319_g30.jpg</File>
    <File>cinf-20240319_g31.jpg</File>
    <File>cinf-20240319_g32.jpg</File>
    <File>cinf-20240319_g33.jpg</File>
    <File>cinf-20240319_g4.jpg</File>
    <File>cinf-20240319_g5.jpg</File>
    <File>cinf-20240319_g6.jpg</File>
    <File>cinf-20240319_g7.jpg</File>
    <File>cinf-20240319_g8.jpg</File>
    <File>cinf-20240319_g9.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="4">http://fasb.org/us-gaap/2023</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/dei/2023</BaseTaxonomy>
    <BaseTaxonomy items="101">http://xbrl.sec.gov/ecd/2023</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
