<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2025"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="krro-20251107.xsd" xlink:type="simple"/>
    <context id="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001703647</identifier>
        </entity>
        <period>
            <startDate>2025-11-07</startDate>
            <endDate>2025-11-07</endDate>
        </period>
    </context>
    <dei:AmendmentFlag
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_7aa547ca-6c97-4340-add9-8c9a4362f516">false</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_6684189c-9e0d-4de3-850e-33e8d4235adb">0001703647</dei:EntityCentralIndexKey>
    <dei:SecurityExchangeName
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_5d2b8890-100a-465b-bdeb-475bebf73187">NASDAQ</dei:SecurityExchangeName>
    <dei:DocumentType
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_3bbd7cda-08bf-400f-b8f5-25292ddf002d">8-K</dei:DocumentType>
    <dei:DocumentPeriodEndDate
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_b15c85a7-fdf9-44e9-b82a-e4f7f7d44d95">2025-11-07</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_e96ed83b-c8d6-420a-94b1-6609d8964de8">Korro Bio, Inc.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_dfab790d-8784-427b-97dd-705304ea928f">DE</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_ca0a7b06-d744-4e72-bc8f-699034700c5d">001-39062</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_7bcb950b-22c5-4821-acb1-701d6a9586a3">47-2324450</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_8ce43697-c061-4020-b9ef-80b1b026f008">60 First Street</dei:EntityAddressAddressLine1>
    <dei:EntityAddressAddressLine2
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_ca4ef93e-6053-499d-8e9e-13cdc5daf617">2nd floor</dei:EntityAddressAddressLine2>
    <dei:EntityAddressAddressLine3
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_a827d149-11b4-4218-ae24-51d8edcf0bc3">Suite 250</dei:EntityAddressAddressLine3>
    <dei:EntityAddressCityOrTown
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_37ea34eb-a1ba-4e10-a5e4-5f5dc227f355">Cambridge</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_042def27-2936-4736-a362-df371bd731cf">MA</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_511ed3b8-820c-49e9-8bea-6e217477ce90">02141</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_3612ee10-5395-42c4-ba33-93ff99fce9ba">(617)</dei:CityAreaCode>
    <dei:LocalPhoneNumber
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_32ad9e34-e93c-4038-84d1-1fd395e952e7">468-1999</dei:LocalPhoneNumber>
    <dei:WrittenCommunications
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_4aa7bb3a-7fd5-4b75-912e-9f12767ac0b0">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_c6cb9284-d5c9-414d-ad24-873a49463a3c">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_b00e3194-9731-4fc3-9f7d-3b06a16b929d">false</dei:PreCommencementTenderOffer>
    <dei:PreCommencementIssuerTenderOffer
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_29bbbb91-3d31-4bad-a4f4-031414d5c6bb">false</dei:PreCommencementIssuerTenderOffer>
    <dei:Security12bTitle
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_a7eaaa55-f278-41a9-bce7-b1bed6cfc396">Common stock, par value $0.001 per share</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_152b1dfa-401b-44bd-b2a8-6308acf04bd0">KRRO</dei:TradingSymbol>
    <dei:EntityEmergingGrowthCompany
      contextRef="C_5afd0513-ea9c-4130-ba73-35563aeaf2b8"
      id="F_077e453d-8cc0-4b21-bdbf-de5a177b18ef">false</dei:EntityEmergingGrowthCompany>
</xbrl>
