<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2026"
  xmlns:ffd="http://xbrl.sec.gov/ffd/2026"
  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/2026/ffd-2026.xsd"
      xlink:type="simple"/>
    <context id="rc">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001513363</identifier>
        </entity>
        <period>
            <startDate>2026-06-29</startDate>
            <endDate>2026-06-29</endDate>
        </period>
    </context>
    <context id="offrl_1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001513363</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>1</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-06-29</startDate>
            <endDate>2026-06-29</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-333">N-14</ffd:FormTp>
    <ffd:SubmissnTp contextRef="rc" id="ixv-334">N-14 8C</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="rc" id="ixv-335">EX-FILING FEES</ffd:FeeExhibitTp>
    <dei:EntityCentralIndexKey contextRef="rc" id="ixv-336">0001513363</dei:EntityCentralIndexKey>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-337">FIDUS INVESTMENT Corp</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-365">N-14</ffd:FormTp>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-366">FIDUS INVESTMENT Corp</dei:EntityRegistrantName>
    <ffd:PrevslyPdFlg contextRef="offrl_1" id="ixv-367">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_1" id="ixv-368">Debt</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_1" id="ixv-369">6.625% Notes due 2029</ffd:OfferingSctyTitl>
    <ffd:Rule457aFlg contextRef="offrl_1" id="ixv-370">true</ffd:Rule457aFlg>
    <ffd:AmtSctiesRegd
      contextRef="offrl_1"
      decimals="0"
      id="ixv-371"
      unitRef="Shares">120000000</ffd:AmtSctiesRegd>
    <ffd:MaxAggtOfferingPric
      contextRef="offrl_1"
      decimals="2"
      id="ixv-372"
      unitRef="USD">120000000.00</ffd:MaxAggtOfferingPric>
    <ffd:FeeRate
      contextRef="offrl_1"
      decimals="7"
      id="ixv-373"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_1"
      decimals="2"
      id="ixv-374"
      unitRef="USD">16572.00</ffd:FeeAmt>
    <ffd:TtlOfferingAmt contextRef="rc" decimals="2" id="ixv-375" unitRef="USD">120000000.00</ffd:TtlOfferingAmt>
    <ffd:TtlFeeAmt contextRef="rc" decimals="2" id="ixv-376" unitRef="USD">16572.00</ffd:TtlFeeAmt>
    <ffd:TtlPrevslyPdAmt contextRef="rc" decimals="2" id="ixv-377" unitRef="USD">0.00</ffd:TtlPrevslyPdAmt>
    <ffd:TtlOffsetAmt contextRef="rc" decimals="2" id="ixv-378" unitRef="USD">0.00</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="rc" decimals="2" id="ixv-379" unitRef="USD">16572.00</ffd:NetFeeAmt>
    <ffd:Rule457fFlg contextRef="offrl_1" id="ixv-380">true</ffd:Rule457fFlg>
    <ffd:OfferingNote contextRef="offrl_1" id="ixv-381">Estimated solely for the purpose of calculating the registration fee required by Section 6(b) of the Securities Act of 1933, as amended (the "Securities Act") and computed pursuant to Rule 457(a) and 457(f)(2) of the Securities Act.</ffd:OfferingNote>
    <ffd:AmtSctiesRcvd
      contextRef="offrl_1"
      decimals="0"
      id="ixv-382"
      unitRef="Shares">120000000</ffd:AmtSctiesRcvd>
    <ffd:ValSctiesRcvdPerShr
      contextRef="offrl_1"
      decimals="2"
      id="ixv-383"
      unitRef="USD">1.00</ffd:ValSctiesRcvdPerShr>
    <ffd:ValSctiesRcvd
      contextRef="offrl_1"
      decimals="2"
      id="ixv-384"
      unitRef="USD">120000000.00</ffd:ValSctiesRcvd>
    <ffd:FeeNoteMaxAggtOfferingPric
      contextRef="offrl_1"
      decimals="2"
      id="ixv-385"
      unitRef="USD">120000000.00</ffd:FeeNoteMaxAggtOfferingPric>
</xbrl>
