<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2026"
  xmlns:fnd="http://xbrl.sec.gov/fnd/2026"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="ft13143-20260812.xsd" xlink:type="simple"/>
    <context id="AsOf2026-08-12">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0002134660</identifier>
        </entity>
        <period>
            <startDate>2026-08-12</startDate>
            <endDate>2026-08-12</endDate>
        </period>
    </context>
    <dei:AmendmentFlag contextRef="AsOf2026-08-12" id="Fact000003">false</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey contextRef="AsOf2026-08-12" id="Fact000004">0002134660</dei:EntityCentralIndexKey>
    <dei:DocumentType contextRef="AsOf2026-08-12" id="Fact000010">S-6</dei:DocumentType>
    <dei:EntityRegistrantName contextRef="AsOf2026-08-12" id="Fact000011">FT 13143</dei:EntityRegistrantName>
    <dei:DocumentPeriodEndDate contextRef="AsOf2026-08-12" id="Fact000012">2026-08-12</dei:DocumentPeriodEndDate>
    <fnd:NmRule35d1TermDfnTextBlock contextRef="AsOf2026-08-12" id="Fact000013">

&lt;p style="font: bold 11pt/12pt Times New Roman, Times, Serif; margin: 0pt 0"&gt;Objectives.&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.25in"&gt;&lt;span style="letter-spacing: -0.05pt"&gt;The
Trust seeks a high rate of monthly income and capital appreciation.&lt;/span&gt;&lt;/p&gt;

</fnd:NmRule35d1TermDfnTextBlock>
    <fnd:NmRule35d1TermSlctnCritTextBlock contextRef="AsOf2026-08-12" id="Fact000014">

&lt;p style="font: bold 11pt/12pt Times New Roman, Times, Serif; margin: 0pt 0"&gt;Portfolio Selection Process.&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.25in"&gt;&lt;span style="letter-spacing: -0.05pt"&gt;The
Trust invests approximately 50% in common stocks of companies which have above-average dividend yields and approximately 50% in closed-end
funds which invest primarily in U.S. and foreign taxable bonds. &lt;/span&gt;&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.25in"&gt;&lt;span style="letter-spacing: -0.05pt"&gt;The
Closed-End Funds were selected by our research department based on a number of factors including, but not limited to, the size and liquidity
of the Closed-End Fund, the current dividend yield of the Closed-End Fund, the quality and character of the securities held by the Closed-End
Fund, and the expense ratio of the Closed-End Fund, while attempting to limit the overlap of the securities held by the Closed-End Funds.
&lt;/span&gt;&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.25in"&gt;&lt;span style="letter-spacing: -0.05pt"&gt;Our
selection process attempts to find the common stocks with the best prospects for a high rate of monthly income and capital appreciation
by identifying those that meet our investment objectives, trade at attractive valuations, and, in our opinion, are likely to exceed market
expectations of future cash flows.&lt;/span&gt;&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.25in"&gt;&lt;span style="letter-spacing: -0.05pt"&gt;While
not a part of the Trust&#x2019;s portfolio selection process, the Trust has exposure to foreign securities, depositary receipts and large
capitalization companies through the Trust&#x2019;s investments in the Common Stocks and high-yield securities, investment grade securities,
depositary receipts and large capitalization companies through the Trust&#x2019;s investments in the Funds.&lt;/span&gt;&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.25in"&gt;&lt;span style="letter-spacing: -0.05pt"&gt;As
with any similar investments, there can be no guarantee that the objectives of the Trust will be achieved. See &#x201c;Risk Factors&#x201d;
for a discussion of the risks of investing in the Trust.&lt;/span&gt;&lt;/p&gt;

</fnd:NmRule35d1TermSlctnCritTextBlock>
</xbrl>
