<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xml:lang="en-US"
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2025"
  xmlns:ffd="http://xbrl.sec.gov/ffd/2025"
  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">
    <link:schemaRef
      xlink:href="https://xbrl.sec.gov/ffd/2025/ffd-2025.xsd"
      xlink:type="simple"/>
    <context id="c-1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001178819</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>1</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-08-08</startDate>
            <endDate>2025-08-08</endDate>
        </period>
    </context>
    <context id="c-2">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001178819</identifier>
        </entity>
        <period>
            <startDate>2025-08-08</startDate>
            <endDate>2025-08-08</endDate>
        </period>
    </context>
    <context id="c-3">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001178819</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OffsetAxis">
                    <dei:lineNo>1</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-08-08</startDate>
            <endDate>2025-08-08</endDate>
        </period>
    </context>
    <context id="c-4">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001178819</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OffsetAxis">
                    <dei:lineNo>2</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-08-08</startDate>
            <endDate>2025-08-08</endDate>
        </period>
    </context>
    <unit id="usd">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="number">
        <measure>pure</measure>
    </unit>
    <dei:EntityCentralIndexKey contextRef="c-2" id="f-34">0001178819</dei:EntityCentralIndexKey>
    <dei:EntityRegistrantName contextRef="c-2" id="f-35">Alamos Gold Inc.</dei:EntityRegistrantName>
    <ffd:FormTp contextRef="c-2" id="f-36">F-10</ffd:FormTp>
    <ffd:SubmissnTp contextRef="c-2" id="f-37">F-10</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="c-2" id="f-38">EX-FILING FEES</ffd:FeeExhibitTp>
    <ffd:CombinedProspectusTableNa contextRef="c-2" id="f-39">N/A</ffd:CombinedProspectusTableNa>
    <ffd:PrevslyPdFlg contextRef="c-1" id="f-1">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="c-1" id="f-2">Unallocated (Universal) Shelf</ffd:OfferingSctyTp>
    <ffd:Rule457oFlg contextRef="c-1" id="f-3">true</ffd:Rule457oFlg>
    <ffd:MaxAggtOfferingPric contextRef="c-1" decimals="0" id="f-4" unitRef="usd">500000000</ffd:MaxAggtOfferingPric>
    <ffd:FeeRate contextRef="c-1" decimals="8" id="f-5" unitRef="number">0.00015310</ffd:FeeRate>
    <ffd:FeeAmt contextRef="c-1" decimals="0" id="f-6" unitRef="usd">76550</ffd:FeeAmt>
    <ffd:TtlOfferingAmt contextRef="c-2" decimals="0" id="f-7" unitRef="usd">500000000</ffd:TtlOfferingAmt>
    <ffd:TtlFeeAmt contextRef="c-2" decimals="0" id="f-8" unitRef="usd">76550</ffd:TtlFeeAmt>
    <ffd:TtlPrevslyPdAmt contextRef="c-2" decimals="0" id="f-9" unitRef="usd">0</ffd:TtlPrevslyPdAmt>
    <ffd:TtlOffsetAmt contextRef="c-2" decimals="0" id="f-10" unitRef="usd">55100</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="c-2" decimals="0" id="f-11" unitRef="usd">21450</ffd:NetFeeAmt>
    <ffd:OfferingNote contextRef="c-1" id="f-12">&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:8pt;font-weight:400;line-height:120%;padding-left:8.68pt"&gt;There are being registered under this Registration Statement on Form F-10 (this &#x201c;Registration Statement&#x201d;) such indeterminate number of Common Shares, Warrants, Debt Securities or Subscription Receipts of Alamos Gold Inc. (the &#x201c;Registrant&#x201d;) as shall have an aggregate initial offering price not to exceed US$500,000,000. Any securities registered by this Registration Statement may be sold separately or as units with other securities registered under this Registration Statement. The proposed maximum initial offering price per security will be determined, from time to time, by the Registrant in connection with the sale of the securities under this Registration Statement. &lt;/span&gt;&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:8pt;font-weight:400;line-height:120%;padding-left:8.68pt"&gt;Estimated solely for the purpose of calculating the registration fee pursuant to Rule 457(o) under the U.S. Securities Act of 1933 (the &#x201c;Securities Act&#x201d;) with respect to the securities to be sold by the registrant. In no event will the aggregate offering price of all securities sold by the registrant from time to time pursuant to this registration statement exceed US$500,000,000.&lt;/span&gt;&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:8pt;font-weight:400;line-height:120%;padding-left:8.68pt"&gt;Pursuant to Rule 416 under the Securities Act, this Registration Statement also covers an indeterminate number of additional securities that may be offered or issued by the Registrant in connection with any stock split, stock dividend or any similar transaction.&lt;/span&gt;</ffd:OfferingNote>
    <ffd:OffsetPrrSctyTitl contextRef="c-3" id="f-13">Common Shares, Warrants, Debt Securities or Subscription Receipts</ffd:OffsetPrrSctyTitl>
    <ffd:Rule457pOffsetFlg contextRef="c-4" id="f-14">true</ffd:Rule457pOffsetFlg>
    <ffd:OffsetClmdInd contextRef="c-3" id="f-15">true</ffd:OffsetClmdInd>
    <ffd:Rule457pOffsetFlg contextRef="c-3" id="f-16">true</ffd:Rule457pOffsetFlg>
    <ffd:OffsetPrrFilerNm contextRef="c-3" id="f-17">Alamos Gold Inc.</ffd:OffsetPrrFilerNm>
    <ffd:OffsetPrrFormTp contextRef="c-3" id="f-18">F-10</ffd:OffsetPrrFormTp>
    <ffd:OffsetPrrFileNb contextRef="c-3" id="f-19">333-272309</ffd:OffsetPrrFileNb>
    <ffd:OffsetClmInitlFilgDt contextRef="c-3" id="f-20">2023-05-31</ffd:OffsetClmInitlFilgDt>
    <ffd:OffsetClmdAmt contextRef="c-3" decimals="0" id="f-21" unitRef="usd">55100</ffd:OffsetClmdAmt>
    <ffd:OffsetPrrSctyTp contextRef="c-3" id="f-22">Unallocated (Universal) Shelf</ffd:OffsetPrrSctyTp>
    <ffd:OffsetPrrUnsoldOfferingAmt contextRef="c-3" decimals="0" id="f-23" unitRef="usd">500000000</ffd:OffsetPrrUnsoldOfferingAmt>
    <ffd:Rule457pOffsetFlg contextRef="c-3" id="f-24">true</ffd:Rule457pOffsetFlg>
    <ffd:OffsetClmdInd contextRef="c-4" id="f-25">false</ffd:OffsetClmdInd>
    <ffd:OffsetPrrFilerNm contextRef="c-4" id="f-26">Alamos Gold Inc.</ffd:OffsetPrrFilerNm>
    <ffd:OffsetPrrFormTp contextRef="c-4" id="f-27">F-10</ffd:OffsetPrrFormTp>
    <ffd:OffsetPrrFileNb contextRef="c-4" id="f-28">333-272309</ffd:OffsetPrrFileNb>
    <ffd:OffsetSrcFilgDt contextRef="c-4" id="f-29">2023-05-31</ffd:OffsetSrcFilgDt>
    <ffd:OffsetPrrFeeAmt contextRef="c-4" decimals="0" id="f-30" unitRef="usd">55100</ffd:OffsetPrrFeeAmt>
    <ffd:OffsetExpltnForClmdAmt contextRef="c-3" id="f-31">&lt;span style="color:#000000;font-family:'Times New Roman',serif;font-size:8pt;font-weight:400;line-height:120%;padding-left:8.68pt"&gt;The Registrant previously filed a registration statement on Form F-10 (File No. 333-272309), initially filed on May 31, 2023, and declared effective on June 5, 2023 (the &#x201c;Prior Registration Statement&#x201d;), which registered an indeterminate number of securities to be sold by the Registrant and had an aggregate initial offering price not to exceed $500,000,000. The Registrant previously paid $55,100 in registration fees with respect to the Prior Registration Statement. The Prior Registration Statement was not used, resulting in $500,000,000 as the unsold aggregate offering amount. Accordingly, all of the filing fees from the Prior Registration Statement are being carried over to this Registration Statement, resulting in a fee offset of $55,100. The Registrant has terminated or completed any offerings that included the unsold securities under the Prior Registration Statement.&lt;/span&gt;</ffd:OffsetExpltnForClmdAmt>
    <ffd:TermntnCmpltnWdrwl contextRef="c-3" id="f-33">The Registrant has terminated or completed any offerings that included the unsold securities under the Prior Registration Statement.</ffd:TermntnCmpltnWdrwl>
    <ffd:TermntnCmpltnWdrwl contextRef="c-4" id="f-32">The Registrant has terminated or completed any offerings that included the unsold securities under the Prior Registration Statement.</ffd:TermntnCmpltnWdrwl>
</xbrl>
