<?xml version="1.0" encoding="utf-8"?>
<xbrl
  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_abc30b1a-bcd1-4824-8cdd-235e69b38ed1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001161728</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>1</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-02-24</startDate>
            <endDate>2026-02-24</endDate>
        </period>
    </context>
    <context id="C_b738144e-dab0-4b34-bf66-62f0a416843c">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001161728</identifier>
        </entity>
        <period>
            <startDate>2026-02-24</startDate>
            <endDate>2026-02-24</endDate>
        </period>
    </context>
    <unit id="U_pure">
        <measure>pure</measure>
    </unit>
    <unit id="U_USD">
        <measure>iso4217:USD</measure>
    </unit>
    <ffd:SubmissnTp
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      id="F_281813bd-b572-40c1-9b84-647cb88c55c7">424B5</ffd:SubmissnTp>
    <ffd:RegnFileNb
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      id="F_e8ef5d8e-9a8d-4d2c-88df-b9e0d6869e4a">333-293693</ffd:RegnFileNb>
    <dei:EntityCentralIndexKey
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      id="F_f682ea89-5e50-4678-86aa-4a20525a64f9">0001161728</dei:EntityCentralIndexKey>
    <ffd:FnlPrspctsFlg
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      id="F_7b0d4c6d-ad71-40c4-8606-3df0b178eb8a">false</ffd:FnlPrspctsFlg>
    <ffd:FeeExhibitTp
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      id="F_df65f356-5c3e-49fa-8f72-037b46d057be">EX-FILING FEES</ffd:FeeExhibitTp>
    <ffd:OffsetTableNa
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      id="F_cf0919ea-b26d-44f4-a715-baf36f3823f6">N/A</ffd:OffsetTableNa>
    <ffd:CombinedProspectusTableNa
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      id="F_d66f5667-cf0f-42a9-a589-e65c05c1d7dd">N/A</ffd:CombinedProspectusTableNa>
    <ffd:FormTp
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      id="F_882d0299-cd40-4484-9d9b-d35ac8d8687f">S-3</ffd:FormTp>
    <dei:EntityRegistrantName
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      id="F_6dbb4885-1ae9-42f6-b9be-4401a1ab1619">MGE Energy, Inc.</dei:EntityRegistrantName>
    <ffd:PrevslyPdFlg
      contextRef="C_abc30b1a-bcd1-4824-8cdd-235e69b38ed1"
      id="F_6ad653ee-81e9-40e2-adb2-d4f25a0dc1e3">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp
      contextRef="C_abc30b1a-bcd1-4824-8cdd-235e69b38ed1"
      id="F_8ab0fb05-b76d-4e8c-bae0-d716fcd9bb63">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl
      contextRef="C_abc30b1a-bcd1-4824-8cdd-235e69b38ed1"
      id="F_bd062ccd-68db-45f6-80d0-51aeec6ff5d6">Common Stock, $1 par value per share </ffd:OfferingSctyTitl>
    <ffd:Rule457oFlg
      contextRef="C_abc30b1a-bcd1-4824-8cdd-235e69b38ed1"
      id="F_4744b750-c751-499a-985e-c7c2eda1bdc7">true</ffd:Rule457oFlg>
    <ffd:MaxAggtOfferingPric
      contextRef="C_abc30b1a-bcd1-4824-8cdd-235e69b38ed1"
      decimals="2"
      id="F_aab8ad35-94b8-4810-94e6-0de040e84b8e"
      unitRef="U_USD">100000000</ffd:MaxAggtOfferingPric>
    <ffd:FeeRate
      contextRef="C_abc30b1a-bcd1-4824-8cdd-235e69b38ed1"
      decimals="7"
      id="F_333104ff-af09-4413-a291-f2defb657ae8"
      unitRef="U_pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="C_abc30b1a-bcd1-4824-8cdd-235e69b38ed1"
      decimals="2"
      id="F_92d5445a-78b8-4ddc-beb7-7d0717c41e9d"
      unitRef="U_USD">13810</ffd:FeeAmt>
    <ffd:TtlOfferingAmt
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      decimals="2"
      id="F_bd01dd9b-a615-4752-a19b-a607f22b3f39"
      unitRef="U_USD">100000000</ffd:TtlOfferingAmt>
    <ffd:TtlFeeAmt
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      decimals="2"
      id="F_932d7f36-14e9-4f4f-92b5-f10595fda3e7"
      unitRef="U_USD">13810</ffd:TtlFeeAmt>
    <ffd:TtlPrevslyPdAmt
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      decimals="-3"
      id="F_440298c0-a184-4802-a484-ccc6060fff2c"
      unitRef="U_USD">0</ffd:TtlPrevslyPdAmt>
    <ffd:TtlOffsetAmt
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      decimals="-3"
      id="F_cedf6299-6710-4812-92c7-f7f441a7d569"
      unitRef="U_USD">0</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt
      contextRef="C_b738144e-dab0-4b34-bf66-62f0a416843c"
      decimals="2"
      id="F_3541b5a8-5898-43d2-84fb-af8f57574102"
      unitRef="U_USD">13810</ffd:NetFeeAmt>
    <ffd:OfferingNote
      contextRef="C_abc30b1a-bcd1-4824-8cdd-235e69b38ed1"
      id="F_7980a2fe-480b-45fa-bd68-d90a82ff3d8a">&lt;span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;"&gt; Calculated in accordance with Rules 457(o) and 457(r) under the Securities Act of 1933, as amended (the &#x201c;Securities Act&#x201d;) based on the proposed maximum aggregate offering price. Table 1 above shall be deemed to update the "Calculation of Filing Fee Table" in the registrant&#x2019;s Registration Statement on Form S-3 (File No. 333-293693).&lt;/span&gt;</ffd:OfferingNote>
</xbrl>
