<?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"
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  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">0001801198</identifier>
        </entity>
        <period>
            <startDate>2026-10-06</startDate>
            <endDate>2026-10-06</endDate>
        </period>
    </context>
    <context id="offrl_1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001801198</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>1</dei:lineNo>
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        <period>
            <startDate>2026-10-06</startDate>
            <endDate>2026-10-06</endDate>
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    </context>
    <unit id="USD">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="pure">
        <measure>pure</measure>
    </unit>
    <unit id="Shares">
        <measure>shares</measure>
    </unit>
    <ffd:FormTp contextRef="rc" id="ixv-168">S-8</ffd:FormTp>
    <ffd:SubmissnTp contextRef="rc" id="ixv-169">S-8</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="rc" id="ixv-170">EX-FILING FEES</ffd:FeeExhibitTp>
    <dei:EntityCentralIndexKey contextRef="rc" id="ixv-171">0001801198</dei:EntityCentralIndexKey>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-172">Legend Biotech Corp</dei:EntityRegistrantName>
    <ffd:OfferingTableNa contextRef="rc" id="hiddenrcOfferingTableNa" xsi:nil="true"/>
    <ffd:OffsetTableNa contextRef="rc" id="hiddenrcOffsetTableNa">N/A</ffd:OffsetTableNa>
    <ffd:PrevslyPdFlg contextRef="offrl_1" id="ixv-175">false</ffd:PrevslyPdFlg>
    <ffd:FormTp contextRef="rc" id="ixv-200">S-8</ffd:FormTp>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-201">Legend Biotech Corp</dei:EntityRegistrantName>
    <ffd:OfferingSctyTp contextRef="offrl_1" id="ixv-202">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_1" id="ixv-203">Ordinary shares, par value US$0.0001 per share</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_1" id="ixv-204">true</ffd:FeesOthrRuleFlg>
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      contextRef="offrl_1"
      decimals="0"
      id="ixv-205"
      unitRef="Shares">19100000</ffd:AmtSctiesRegd>
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      contextRef="offrl_1"
      decimals="2"
      id="ixv-206"
      unitRef="USD">9.19</ffd:MaxOfferingPricPerScty>
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      contextRef="offrl_1"
      decimals="2"
      id="ixv-207"
      unitRef="USD">175529000.00</ffd:MaxAggtOfferingPric>
    <ffd:FeeRate
      contextRef="offrl_1"
      decimals="6"
      id="ixv-208"
      unitRef="pure">0.000087</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_1"
      decimals="2"
      id="ixv-209"
      unitRef="USD">15271.02</ffd:FeeAmt>
    <ffd:TtlOfferingAmt contextRef="rc" decimals="2" id="ixv-210" unitRef="USD">175529000.00</ffd:TtlOfferingAmt>
    <ffd:TtlFeeAmt contextRef="rc" decimals="2" id="ixv-211" unitRef="USD">15271.02</ffd:TtlFeeAmt>
    <ffd:TtlOffsetAmt contextRef="rc" decimals="2" id="ixv-212" unitRef="USD">0.00</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="rc" decimals="2" id="ixv-213" unitRef="USD">15271.02</ffd:NetFeeAmt>
    <ffd:OfferingNote contextRef="offrl_1" id="ixv-214">(A) These shares may be represented by the American Depositary Shares ('ADSs') of Legend Biotech Corporation (the 'Registrant'). Each ADS represents two ordinary shares. ADSs issuable upon deposit of the ordinary shares registered hereby were registered pursuant to the separate Registration Statements on Form F-6 (File Nos. 333-238581 and 333-296862). (B) Pursuant to Rule 416(a) under the Securities Act of 1933, as amended (the 'Securities Act'), this Registration Statement shall also cover any additional ordinary shares of the Registrant that become issuable under the Registrant's Amended and Restated 2020 Restricted Shares Plan (the 'RSU Plan') by reason of any stock dividend, stock split, recapitalization or other similar transaction. (C) Estimated solely for the purpose of determining the registration fee pursuant to Rules 457(c) and (h) under the Securities Act, based upon the average of the high and low prices of the Registrant's ADSs as quoted on the Nasdaq Global Select Market on October 5, 2026. (D) Represents ordinary shares that became available for issuance under the RSU Plan, effective as of September 24, 2026.  </ffd:OfferingNote>
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