<?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="ft13070-20260707.xsd" xlink:type="simple"/>
    <context id="AsOf2026-07-07">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0002130922</identifier>
        </entity>
        <period>
            <startDate>2026-07-07</startDate>
            <endDate>2026-07-07</endDate>
        </period>
    </context>
    <dei:AmendmentFlag contextRef="AsOf2026-07-07" id="Fact000003">false</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey contextRef="AsOf2026-07-07" id="Fact000004">0002130922</dei:EntityCentralIndexKey>
    <dei:DocumentType contextRef="AsOf2026-07-07" id="Fact000010">S-6</dei:DocumentType>
    <dei:EntityRegistrantName contextRef="AsOf2026-07-07" id="Fact000011">FT 13070</dei:EntityRegistrantName>
    <dei:DocumentPeriodEndDate contextRef="AsOf2026-07-07" id="Fact000012">2026-07-07</dei:DocumentPeriodEndDate>
    <fnd:NmRule35d1TermDfnTextBlock contextRef="AsOf2026-07-07" id="Fact000013">

&lt;p style="font: bold 11pt/12pt Times New Roman, Times, Serif; margin: 4pt 0 1pt"&gt;Objective.&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0 0 2pt; text-indent: 0.25in"&gt;&lt;span style="letter-spacing: -0.05pt"&gt;The
Trust seeks above-average total return through a combination of capital appreciation and dividend income. Under normal circumstances,
the Trust will invest at least 80% of its assets in closed-end funds which invest at least 80% of their assets in dividend-paying securities.&lt;/span&gt;&lt;/p&gt;

</fnd:NmRule35d1TermDfnTextBlock>
    <fnd:NmRule35d1TermSlctnCritTextBlock contextRef="AsOf2026-07-07" id="Fact000014">

&lt;p style="font: bold 11pt/12pt Times New Roman, Times, Serif; margin: 4pt 0 1pt"&gt;Portfolio Selection Process.&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0 0 2pt; text-indent: 0.25in"&gt;&lt;span style="letter-spacing: -0.05pt"&gt;The
Trust is a unit investment trust that is comprised of a pool of closed-end funds which invest in dividend-paying common stocks and preferred
securities. A portion of these closed-end funds invest in common stocks and, on an ongoing basis, will sell covered call options. An option
is considered &#x201c;covered&#x201d; when a closed-end fund owns the equity securities against which the options are sold.&lt;/span&gt;&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0 0 2pt; 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: 0 0 2pt; text-indent: 0.25in"&gt;While not a part of the Trust&#x2019;s portfolio
selection process, the Trust has exposure to floating-rate securities, &lt;span style="letter-spacing: -0.05pt"&gt;foreign securities, depositary
receipts and companies with various market capitalizations through the Trust&#x2019;s investment in the Funds. &lt;/span&gt;&lt;/p&gt;

&lt;p style="font: 10pt/11pt Times New Roman, Times, Serif; margin: 0 0 2pt; text-indent: 0.25in"&gt;&lt;span style="letter-spacing: -0.05pt"&gt;As
with any similar investment, there can be no guarantee that the objective 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>
