<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:ck0001048607="http://www.lfg.com/20260501"
  xmlns:dei="http://xbrl.sec.gov/dei/2026"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:vip="http://xbrl.sec.gov/vip/2026"
  xmlns:xbrldi="http://xbrl.org/2006/xbrldi"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="ck0001048607-20260501.xsd" xlink:type="simple"/>
    <context id="c0">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001048607</identifier>
        </entity>
        <period>
            <startDate>2026-05-01</startDate>
            <endDate>2026-05-01</endDate>
        </period>
    </context>
    <context id="c1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001048607</identifier>
            <segment>
                <xbrldi:explicitMember dimension="vip:PortfolioCompanyAxis">ck0001048607:AmericanFundsISSMALLCAPWorldFundMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-05-01</startDate>
            <endDate>2026-05-01</endDate>
        </period>
    </context>
    <context id="c2">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001048607</identifier>
            <segment>
                <xbrldi:explicitMember dimension="vip:PortfolioCompanyAxis">ck0001048607:AmericanFundsISEUPACFundMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-05-01</startDate>
            <endDate>2026-05-01</endDate>
        </period>
    </context>
    <dei:EntityRegistrantName contextRef="c0" id="ixv-16">Lincoln Life Flexible Premium Variable Life Account M</dei:EntityRegistrantName>
    <dei:DocumentPeriodEndDate contextRef="c0" id="ixv-188">2026-05-01</dei:DocumentPeriodEndDate>
    <vip:PortfolioCompaniesN6TextBlock contextRef="c0" id="ixv-138">&lt;p style="font: 10pt Arial, Helvetica, Sans-Serif; margin: 0pt 0"&gt;Effective May 1, 2026, the following American Funds Insurance Series
fund names will be updated as follows:&lt;/p&gt;




&lt;p style="font: 10pt Arial, Helvetica, Sans-Serif; margin: 0pt 0"&gt;&#160;&lt;/p&gt;




&lt;table cellpadding="0" style="font: 11pt Arial, Helvetica, Sans-Serif; width: 100%; border-collapse: collapse; border-spacing: 0px;"&gt; &lt;tr style="vertical-align: top"&gt; &lt;td style="width: 53%; border-bottom: #666666 1pt solid; padding-right: 5.4pt; padding-left: 5.4pt; text-align: center"&gt;&lt;span style="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt"&gt;&lt;b&gt;FORMER FUND NAME&lt;/b&gt;&lt;/span&gt;&lt;/td&gt; &lt;td style="width: 47%; border-bottom: #666666 1pt solid; padding-right: 5.4pt; padding-left: 5.4pt; text-align: center"&gt;&lt;span style="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt"&gt;&lt;b&gt;NEW FUND NAME&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;&lt;/tr&gt; &lt;tr style="vertical-align: top; background-color: #CCCCCC"&gt; &lt;td style="padding-right: 5.4pt; padding-left: 0.25in"&gt;&lt;span style="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt"&gt;American Funds&lt;sup&gt;&#xae;&lt;/sup&gt; IS Global Small Capitalization Fund&lt;/span&gt;&lt;/td&gt; &lt;td style="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 0.25in"&gt;&lt;span style="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt"&gt;American Funds&lt;sup&gt;&#xae;&lt;/sup&gt; IS SMALLCAP World Fund&lt;/span&gt;&lt;/td&gt;&lt;/tr&gt; &lt;tr style="vertical-align: top"&gt; &lt;td style="padding-right: 5.4pt; padding-left: 0.25in"&gt;&lt;span style="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt"&gt;American Funds&lt;sup&gt;&#xae;&lt;/sup&gt; IS International Fund&lt;/span&gt;&lt;/td&gt; &lt;td style="padding-right: 5.4pt; padding-bottom: 10pt; padding-left: 0.25in"&gt;&lt;span style="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt"&gt;American Funds&lt;sup&gt;&#xae;&lt;/sup&gt; IS EUPAC Fund&lt;/span&gt;&lt;/td&gt;&lt;/tr&gt; &lt;/table&gt;</vip:PortfolioCompaniesN6TextBlock>
    <vip:PortfolioCompanyNameTextBlock contextRef="c1" id="ixv-154">&lt;span style="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt"&gt;American Funds&lt;sup&gt;&#xae;&lt;/sup&gt; IS SMALLCAP World Fund&lt;/span&gt;</vip:PortfolioCompanyNameTextBlock>
    <vip:PortfolioCompanyNameTextBlock contextRef="c2" id="ixv-162">&lt;span style="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt"&gt;American Funds&lt;sup&gt;&#xae;&lt;/sup&gt; IS EUPAC Fund&lt;/span&gt;</vip:PortfolioCompanyNameTextBlock>
    <dei:DocumentType contextRef="c0" id="ixv-191">N-6</dei:DocumentType>
    <dei:EntityInvCompanyType contextRef="c0" id="ixv-192">N-6</dei:EntityInvCompanyType>
    <dei:EntityCentralIndexKey contextRef="c0" id="ixv-193">0001048607</dei:EntityCentralIndexKey>
    <dei:AmendmentFlag contextRef="c0" id="ixv-194">false</dei:AmendmentFlag>
</xbrl>
