<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:bigc="http://www.bigcommerce.com/20261105"
  xmlns:dei="http://xbrl.sec.gov/dei/2026"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:us-gaap="http://fasb.org/us-gaap/2026"
  xmlns:xbrldi="http://xbrl.org/2006/xbrldi"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="bigc-20261105.xsd" xlink:type="simple"/>
    <context id="C_d6d3987d-54ee-46ef-88da-b376be00add3">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001626450</identifier>
            <segment>
                <xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">bigc:SeriesAJuniorParticipatingPreferredStockMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-11-05</startDate>
            <endDate>2026-11-05</endDate>
        </period>
    </context>
    <context id="C_f41d744c-5b55-497c-8e6f-a90469c6c2a9">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001626450</identifier>
            <segment>
                <xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">bigc:SeriesOneCommonStockMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-11-05</startDate>
            <endDate>2026-11-05</endDate>
        </period>
    </context>
    <context id="C_12514f5d-cc02-4895-812f-875b002b6456">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001626450</identifier>
        </entity>
        <period>
            <startDate>2026-11-05</startDate>
            <endDate>2026-11-05</endDate>
        </period>
    </context>
    <dei:AmendmentFlag
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_850253bb-56b6-47c1-ac08-9e6f9527e9d6">false</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_3024a16c-4441-4e0b-adc9-50212ac9dd19">0001626450</dei:EntityCentralIndexKey>
    <dei:DocumentType
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_40e4c521-0b34-4329-ae0a-9a1f22991b86">8-K</dei:DocumentType>
    <dei:DocumentPeriodEndDate
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_2789a3d9-c12d-462b-a8ee-c948b2d83d0d">2026-11-05</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_7e0baf66-12b0-465f-9a83-25c3bc126c37">Commerce.com, Inc.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_f9b07935-196c-4972-8300-a7bd56159dbb">DE</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_d1651b0c-ca1f-4380-bbc8-e8f94be9d401">001-39423</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_95f9db9b-71ea-4ddb-be2d-af2288459dc2">46-2707656</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_ce4a9ad9-712f-43a4-9728-f5900cf0f89a">11920 Alterra Parkway</dei:EntityAddressAddressLine1>
    <dei:EntityAddressAddressLine2
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_a99e8438-8ab5-4e92-a444-a14bbb1e49a9">D11 / Suite 100</dei:EntityAddressAddressLine2>
    <dei:EntityAddressAddressLine3
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_375d6652-a497-4f0a-9715-9b954befc619">8th Floor</dei:EntityAddressAddressLine3>
    <dei:EntityAddressCityOrTown
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_6bb7caae-baa7-417a-bb7d-6d165225715b">Austin</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_32724ccb-76c6-455f-afc2-3e9d9674798e">TX</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_97d3ca60-96e0-4dbe-9221-70af3cd0114e">78758</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_ed2ad416-ee6b-4f19-b6a7-ad0b3b7dbdad">(512)</dei:CityAreaCode>
    <dei:LocalPhoneNumber
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_c5b2432a-f8b6-4fdd-a572-0bc1e271d5b3">865-4500</dei:LocalPhoneNumber>
    <dei:WrittenCommunications
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_07b180db-e787-4ee1-9d7b-c5343e5446c9">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_2c8b67e5-3ab8-422c-9076-7f67d6d46b09">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_2716c123-0cde-43dd-8f62-0e61d23ab553">false</dei:PreCommencementTenderOffer>
    <dei:PreCommencementIssuerTenderOffer
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_aaedaa11-1f7c-4712-a855-30ca13785f0a">false</dei:PreCommencementIssuerTenderOffer>
    <dei:Security12bTitle
      contextRef="C_f41d744c-5b55-497c-8e6f-a90469c6c2a9"
      id="F_53cc7219-467a-45f4-9be4-20ceaea4ff19">Series 1 Common Stock, $0.0001 par value per share</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="C_f41d744c-5b55-497c-8e6f-a90469c6c2a9"
      id="F_825e4ba8-2aef-4c09-a07d-1f38951a88ed">CMRC</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="C_f41d744c-5b55-497c-8e6f-a90469c6c2a9"
      id="F_aae702fa-bee8-4ecd-b68e-78f5ab3902ed">NASDAQ</dei:SecurityExchangeName>
    <dei:Security12bTitle
      contextRef="C_d6d3987d-54ee-46ef-88da-b376be00add3"
      id="F_43860141-47e8-4f52-a8d8-0201984eac45">Series A Junior Participating Preferred Stock, par value $0.0001 per share</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="C_d6d3987d-54ee-46ef-88da-b376be00add3"
      id="F_4c04d9b2-0025-46d4-ac7f-5132c9d1e10e">N/A</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="C_d6d3987d-54ee-46ef-88da-b376be00add3"
      id="F_f0b4bd0d-23ad-4aea-974f-8f78689be226">NASDAQ</dei:SecurityExchangeName>
    <dei:EntityEmergingGrowthCompany
      contextRef="C_12514f5d-cc02-4895-812f-875b002b6456"
      id="F_fb8c23b5-0c21-45b0-b05e-778ebb0a95ea">false</dei:EntityEmergingGrowthCompany>
</xbrl>
