<?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">0001543188</identifier>
        </entity>
        <period>
            <startDate>2026-08-20</startDate>
            <endDate>2026-08-20</endDate>
        </period>
    </context>
    <context id="offrl_1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001543188</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>1</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-08-20</startDate>
            <endDate>2026-08-20</endDate>
        </period>
    </context>
    <unit id="USD">
        <measure>iso4217:USD</measure>
    </unit>
    <ffd:FormTp contextRef="rc" id="ixv-150">SC TO</ffd:FormTp>
    <ffd:SubmissnTp contextRef="rc" id="ixv-151">SC TO-I/A</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="rc" id="ixv-152">EX-FILING FEES</ffd:FeeExhibitTp>
    <dei:EntityCentralIndexKey contextRef="rc" id="ixv-153">0001543188</dei:EntityCentralIndexKey>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-154">AB Multi-Manager Alternative Fund</dei:EntityRegistrantName>
    <ffd:OfferingTableNa contextRef="rc" id="hiddenrcOfferingTableNa" xsi:nil="true"/>
    <ffd:OffsetTableNa contextRef="rc" id="hiddenrcOffsetTableNa">N/A</ffd:OffsetTableNa>
    <ffd:Rule011Flg contextRef="offrl_1" id="ixv-157">true</ffd:Rule011Flg>
    <ffd:PrevslyPdFlg contextRef="offrl_1" id="ixv-182">true</ffd:PrevslyPdFlg>
    <ffd:TxValtn
      contextRef="offrl_1"
      decimals="2"
      id="ixv-183"
      unitRef="USD">109633781.72</ffd:TxValtn>
    <ffd:FeeAmt
      contextRef="offrl_1"
      decimals="2"
      id="ixv-184"
      unitRef="USD">15140.43</ffd:FeeAmt>
    <ffd:TtlTxValtn contextRef="rc" decimals="2" id="ixv-185" unitRef="USD">109633781.72</ffd:TtlTxValtn>
    <ffd:TtlFeeAmt contextRef="rc" decimals="2" id="ixv-186" unitRef="USD">15140.43</ffd:TtlFeeAmt>
    <ffd:TtlPrevslyPdAmt contextRef="rc" decimals="2" id="ixv-187" unitRef="USD">15140.43</ffd:TtlPrevslyPdAmt>
    <ffd:TtlOffsetAmt contextRef="rc" decimals="2" id="ixv-188" unitRef="USD">0.00</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="rc" decimals="2" id="ixv-189" unitRef="USD">0.00</ffd:NetFeeAmt>
    <ffd:OfferingNote contextRef="offrl_1" id="ixv-190">(1) The transaction value was estimated for purposes of calculating the amount of the filing fee only. The amount was based upon the offer to purchase up to 9,068,137 common shares of beneficial interest (10% of the common shares of beneficial interest outstanding as of October 1, 2025, rounded to the nearest whole share) based upon a price per share of $12.09 (the net asset value per share on October 1, 2025). The fee of $15,140.43 was paid in connection with the filing of the Schedule TO-I by AB Multi-Manager Alternative Fund (File No. 005-87063) on November 14, 2025 (the "Schedule TO"). This is the final amendment to the Schedule TO and is being filed to report the results of the offer. (2) Calculated at $138.10 per $1,000,000 of the transaction valuation.</ffd:OfferingNote>
</xbrl>
