<?xml version="1.0" encoding="utf-8"?>
<xbrl
  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="ftci-20251231.xsd" xlink:type="simple"/>
    <context id="c0">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001828161</identifier>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="c1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001828161</identifier>
        </entity>
        <period>
            <instant>2025-06-30</instant>
        </period>
    </context>
    <context id="c2">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001828161</identifier>
        </entity>
        <period>
            <instant>2026-03-20</instant>
        </period>
    </context>
    <unit id="usd">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="shares">
        <measure>shares</measure>
    </unit>
    <dei:DocumentType contextRef="c0" id="ixv-6906">10-K/A</dei:DocumentType>
    <dei:DocumentAnnualReport contextRef="c0" id="ixv-62">true</dei:DocumentAnnualReport>
    <dei:DocumentPeriodEndDate contextRef="c0" id="ixv-6907">2025-12-31</dei:DocumentPeriodEndDate>
    <dei:CurrentFiscalYearEndDate contextRef="c0" id="ixv-6908">--12-31</dei:CurrentFiscalYearEndDate>
    <dei:DocumentFiscalYearFocus contextRef="c0" id="ixv-6909">2025</dei:DocumentFiscalYearFocus>
    <dei:DocumentTransitionReport contextRef="c0" id="ixv-88">false</dei:DocumentTransitionReport>
    <dei:EntityFileNumber contextRef="c0" id="ixv-6910">001-40350</dei:EntityFileNumber>
    <dei:EntityRegistrantName contextRef="c0" id="ixv-110">FTC SOLAR, INC.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode contextRef="c0" id="ixv-127">DE</dei:EntityIncorporationStateCountryCode>
    <dei:EntityTaxIdentificationNumber contextRef="c0" id="ixv-132">81-4816270</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1 contextRef="c0" id="ixv-6911">10900 Stonelake Blvd</dei:EntityAddressAddressLine1>
    <dei:EntityAddressAddressLine2 contextRef="c0" id="ixv-6912">Suite 100</dei:EntityAddressAddressLine2>
    <dei:EntityAddressAddressLine3 contextRef="c0" id="ixv-6913">Quarry Oaks II Building</dei:EntityAddressAddressLine3>
    <dei:EntityAddressCityOrTown contextRef="c0" id="ixv-6914">Austin</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince contextRef="c0" id="ixv-6915">TX</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode contextRef="c0" id="ixv-168">78759</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode contextRef="c0" id="ixv-6916">(512)</dei:CityAreaCode>
    <dei:LocalPhoneNumber contextRef="c0" id="ixv-6917">481-4271</dei:LocalPhoneNumber>
    <dei:Security12bTitle contextRef="c0" id="ixv-216">Common Stock, $0.0001 par value</dei:Security12bTitle>
    <dei:TradingSymbol contextRef="c0" id="ixv-221">FTCI</dei:TradingSymbol>
    <dei:SecurityExchangeName contextRef="c0" id="ixv-6918">NASDAQ</dei:SecurityExchangeName>
    <dei:EntityWellKnownSeasonedIssuer contextRef="c0" id="ixv-240">No</dei:EntityWellKnownSeasonedIssuer>
    <dei:EntityVoluntaryFilers contextRef="c0" id="ixv-249">No</dei:EntityVoluntaryFilers>
    <dei:EntityCurrentReportingStatus contextRef="c0" id="ixv-257">Yes</dei:EntityCurrentReportingStatus>
    <dei:EntityInteractiveDataCurrent contextRef="c0" id="ixv-266">Yes</dei:EntityInteractiveDataCurrent>
    <dei:EntityFilerCategory contextRef="c0" id="ixv-302">Non-accelerated Filer</dei:EntityFilerCategory>
    <dei:EntitySmallBusiness contextRef="c0" id="ixv-310">true</dei:EntitySmallBusiness>
    <dei:EntityEmergingGrowthCompany contextRef="c0" id="ixv-326">true</dei:EntityEmergingGrowthCompany>
    <dei:EntityExTransitionPeriod contextRef="c0" id="ixv-6919">false</dei:EntityExTransitionPeriod>
    <dei:IcfrAuditorAttestationFlag contextRef="c0" id="ixv-6920">false</dei:IcfrAuditorAttestationFlag>
    <dei:DocumentFinStmtErrorCorrectionFlag contextRef="c0" id="ixv-6921">false</dei:DocumentFinStmtErrorCorrectionFlag>
    <dei:EntityShellCompany contextRef="c0" id="ixv-6922">false</dei:EntityShellCompany>
    <dei:EntityPublicFloat contextRef="c1" decimals="0" id="ixv-6923" unitRef="usd">38128743</dei:EntityPublicFloat>
    <dei:EntityCommonStockSharesOutstanding
      contextRef="c2"
      decimals="INF"
      id="ixv-6924"
      unitRef="shares">15585198</dei:EntityCommonStockSharesOutstanding>
    <dei:AmendmentDescription contextRef="c0" id="ixv-406">FTC
Solar, Inc. is filing this Amendment No. 1 on Form 10-K/A, or this Amendment No. 1, to our Annual Report on Form 10-K for the fiscal year
ended December 31, 2025, or the Original 10-K, originally filed with the U.S. Securities and Exchange Commission, or SEC, on March 24,
2026, or Original Filing Date, solely for the purpose of including the information required by Items 10 through 14 of Part III of Form
10-K. This information was previously omitted from the Original 10-K in reliance on General Instruction G(3) to Form 10-K, which permits
the information in the above referenced items to be incorporated in the Original 10-K by reference from our definitive proxy statement
so long as such proxy statement is filed no later than 120 days after our fiscal year-end. We are filing this Amendment No. 1 to include
the Part III information in the Original Form 10-K because we will not file a definitive proxy statement containing such information
within 120 days after the end of the fiscal year covered by the Original 10-K.This Amendment No. 1 amends and restates in their entirety the cover
page and Items 10 through 14 of the Original 10-K. Pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, as amended, or the
Exchange Act, this Amendment No. 1 also contains new certifications by the principal executive officer and the principal financial officer
as required by Section 302 of the Sarbanes-Oxley Act of 2002. Accordingly, Item 15 of Part IV is amended to include the currently dated
certifications of our principal executive officer and principal financial officer as exhibits.Except
as described above, no other changes have been made to the Original 10-K. The Original 10-K continues to speak as of the date of the
Original 10-K, and we have not updated the disclosures contained therein to reflect any events that have occurred as of a date subsequent
to the date of the Original 10-K. Accordingly, this Amendment No. 1 should be read in conjunction with the Original 10-K. Defined terms
used, but not defined, herein have the meanings ascribed to them in the Original 10-K.Unless
stated otherwise, references in this Amendment No. 1 to &#x201c;FTC,&#x201d; &#x201c;the Company&#x201d;, &#x201c;we&#x201d;, &#x201c;our&#x201d;
and &#x201c;us&#x201d; are used herein to refer to FTC Solar, Inc.</dei:AmendmentDescription>
    <ecd:InsiderTrdPoliciesProcAdoptedFlag contextRef="c0" id="ixv-6925">true</ecd:InsiderTrdPoliciesProcAdoptedFlag>
    <dei:EntityCentralIndexKey contextRef="c0" id="ixv-6928">0001828161</dei:EntityCentralIndexKey>
    <dei:AmendmentFlag contextRef="c0" id="ixv-6929">true</dei:AmendmentFlag>
    <dei:DocumentFiscalPeriodFocus contextRef="c0" id="ixv-6930">FY</dei:DocumentFiscalPeriodFocus>
</xbrl>
