<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2025"
  xmlns:ffd="http://xbrl.sec.gov/ffd/2025q4"
  xmlns:iso4217="http://www.xbrl.org/2003/iso4217"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xbrldi="http://xbrl.org/2006/xbrldi"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <link:schemaRef
      xlink:href="https://xbrl.sec.gov/ffd/2025q4/ffd-2025q4.xsd"
      xlink:type="simple"/>
    <context id="rc">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000091576</identifier>
        </entity>
        <period>
            <startDate>2026-01-22</startDate>
            <endDate>2026-01-22</endDate>
        </period>
    </context>
    <context id="offrl_1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000091576</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>1</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-01-22</startDate>
            <endDate>2026-01-22</endDate>
        </period>
    </context>
    <unit id="USD">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="pure">
        <measure>pure</measure>
    </unit>
    <unit id="Shares">
        <measure>shares</measure>
    </unit>
    <ffd:FormTp contextRef="rc" id="ixv-345">S-3</ffd:FormTp>
    <ffd:SubmissnTp contextRef="rc" id="ixv-346">424B5</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="rc" id="ixv-347">EX-FILING FEES</ffd:FeeExhibitTp>
    <ffd:RegnFileNb contextRef="rc" id="ixv-348">333-272573</ffd:RegnFileNb>
    <dei:EntityCentralIndexKey contextRef="rc" id="ixv-349">0000091576</dei:EntityCentralIndexKey>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-350">KEYCORP /NEW/</dei:EntityRegistrantName>
    <ffd:OfferingTableNa contextRef="rc" id="hiddenrcOfferingTableNa" xsi:nil="true"/>
    <ffd:OffsetTableNa contextRef="rc" id="hiddenrcOffsetTableNa">N/A</ffd:OffsetTableNa>
    <ffd:CombinedProspectusTableNa contextRef="rc" id="hiddenrcCombinedProspectusTableNa">N/A</ffd:CombinedProspectusTableNa>
    <ffd:FormTp contextRef="rc" id="ixv-378">S-3</ffd:FormTp>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-379">KEYCORP /NEW/</dei:EntityRegistrantName>
    <ffd:PrevslyPdFlg contextRef="offrl_1" id="ixv-380">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_1" id="ixv-381">Debt</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_1" id="ixv-382">5.305% Fixed-to-Floating Rate Senior Notes due 2037</ffd:OfferingSctyTitl>
    <ffd:Rule457rFlg contextRef="offrl_1" id="ixv-383">true</ffd:Rule457rFlg>
    <ffd:AmtSctiesRegd
      contextRef="offrl_1"
      decimals="0"
      id="ixv-384"
      unitRef="Shares">750000000</ffd:AmtSctiesRegd>
    <ffd:MaxOfferingPricPerScty
      contextRef="offrl_1"
      decimals="2"
      id="ixv-385"
      unitRef="USD">1.00</ffd:MaxOfferingPricPerScty>
    <ffd:MaxAggtOfferingPric
      contextRef="offrl_1"
      decimals="2"
      id="ixv-386"
      unitRef="USD">750000000.00</ffd:MaxAggtOfferingPric>
    <ffd:FeeRate
      contextRef="offrl_1"
      decimals="7"
      id="ixv-387"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_1"
      decimals="2"
      id="ixv-388"
      unitRef="USD">103575.00</ffd:FeeAmt>
    <ffd:TtlOfferingAmt contextRef="rc" decimals="2" id="ixv-389" unitRef="USD">750000000.00</ffd:TtlOfferingAmt>
    <ffd:TtlFeeAmt contextRef="rc" decimals="2" id="ixv-390" unitRef="USD">103575.00</ffd:TtlFeeAmt>
    <ffd:TtlPrevslyPdAmt contextRef="rc" decimals="2" id="ixv-391" unitRef="USD">0.00</ffd:TtlPrevslyPdAmt>
    <ffd:TtlOffsetAmt contextRef="rc" decimals="2" id="ixv-392" unitRef="USD">0.00</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="rc" decimals="2" id="ixv-393" unitRef="USD">103575.00</ffd:NetFeeAmt>
    <ffd:OfferingNote contextRef="offrl_1" id="ixv-394">The filing fee is calculated in accordance with Rules 457(o) and 457(r) of the Securities Act of 1933, as amended (the "Securities Act"). In accordance with Rules 456(b) and 457(r) of the Securities Act, the registrant initially deferred payment of all of the registration fee for Registration Statement No. 333-2272573 filed on June 9, 2023.</ffd:OfferingNote>
    <ffd:NrrtvMaxAggtOfferingPric contextRef="rc" decimals="2" id="ixv-395" unitRef="USD">750000000.00</ffd:NrrtvMaxAggtOfferingPric>
    <ffd:FnlPrspctsFlg contextRef="rc" id="ixv-396">true</ffd:FnlPrspctsFlg>
</xbrl>
