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        <period>
            <startDate>2026-03-05</startDate>
            <endDate>2026-03-05</endDate>
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    <unit id="USD">
        <measure>iso4217:USD</measure>
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    <unit id="pure">
        <measure>pure</measure>
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    <ffd:FormTp contextRef="rc" id="ixv-442">S-3</ffd:FormTp>
    <ffd:SubmissnTp contextRef="rc" id="ixv-443">S-3</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="rc" id="ixv-444">EX-FILING FEES</ffd:FeeExhibitTp>
    <dei:EntityCentralIndexKey contextRef="rc" id="ixv-445">0000931148</dei:EntityCentralIndexKey>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-446">GRAFTECH INTERNATIONAL LTD</dei:EntityRegistrantName>
    <ffd:OfferingTableNa contextRef="rc" id="hiddenrcOfferingTableNa" xsi:nil="true"/>
    <ffd:OffsetTableNa contextRef="rc" id="hiddenrcOffsetTableNa">N/A</ffd:OffsetTableNa>
    <ffd:CombinedProspectusTableNa contextRef="rc" id="hiddenrcCombinedProspectusTableNa">N/A</ffd:CombinedProspectusTableNa>
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      decimals="7"
      id="ixv-450"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeRate
      contextRef="offrl_2"
      decimals="7"
      id="ixv-451"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeRate
      contextRef="offrl_3"
      decimals="7"
      id="ixv-452"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeRate
      contextRef="offrl_4"
      decimals="7"
      id="ixv-453"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeRate
      contextRef="offrl_5"
      decimals="7"
      id="ixv-454"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeRate
      contextRef="offrl_6"
      decimals="7"
      id="ixv-455"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeRate
      contextRef="offrl_7"
      decimals="7"
      id="ixv-456"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FormTp contextRef="rc" id="ixv-544">S-3</ffd:FormTp>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-545">GRAFTECH INTERNATIONAL LTD</dei:EntityRegistrantName>
    <ffd:OfferingSctyTp contextRef="offrl_1" id="ixv-546">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_1" id="ixv-547">Common Stock, par value $0.01 per share</ffd:OfferingSctyTitl>
    <ffd:Rule457oFlg contextRef="offrl_1" id="ixv-548">true</ffd:Rule457oFlg>
    <ffd:OfferingSctyTp contextRef="offrl_2" id="ixv-549">Equity</ffd:OfferingSctyTp>
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    <ffd:Rule457oFlg contextRef="offrl_2" id="ixv-551">true</ffd:Rule457oFlg>
    <ffd:OfferingSctyTp contextRef="offrl_3" id="ixv-552">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_3" id="ixv-553">Depositary Shares</ffd:OfferingSctyTitl>
    <ffd:Rule457oFlg contextRef="offrl_3" id="ixv-554">true</ffd:Rule457oFlg>
    <ffd:OfferingSctyTp contextRef="offrl_4" id="ixv-555">Other</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_4" id="ixv-556">Warrants</ffd:OfferingSctyTitl>
    <ffd:Rule457oFlg contextRef="offrl_4" id="ixv-557">true</ffd:Rule457oFlg>
    <ffd:OfferingSctyTp contextRef="offrl_5" id="ixv-558">Debt</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_5" id="ixv-559">Debt Securities</ffd:OfferingSctyTitl>
    <ffd:Rule457oFlg contextRef="offrl_5" id="ixv-560">true</ffd:Rule457oFlg>
    <ffd:OfferingSctyTp contextRef="offrl_6" id="ixv-561">Other</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_6" id="ixv-562">Purchase Contracts</ffd:OfferingSctyTitl>
    <ffd:Rule457oFlg contextRef="offrl_6" id="ixv-563">true</ffd:Rule457oFlg>
    <ffd:OfferingSctyTp contextRef="offrl_7" id="ixv-564">Other</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_7" id="ixv-565">Units</ffd:OfferingSctyTitl>
    <ffd:Rule457oFlg contextRef="offrl_7" id="ixv-566">true</ffd:Rule457oFlg>
    <ffd:PrevslyPdFlg contextRef="offrl_8" id="ixv-567">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_8" id="ixv-568">Unallocated (Universal) Shelf</ffd:OfferingSctyTp>
    <ffd:Rule457oFlg contextRef="offrl_8" id="ixv-569">true</ffd:Rule457oFlg>
    <ffd:MaxAggtOfferingPric
      contextRef="offrl_8"
      decimals="2"
      id="ixv-570"
      unitRef="USD">150000000.00</ffd:MaxAggtOfferingPric>
    <ffd:FeeRate
      contextRef="offrl_8"
      decimals="7"
      id="ixv-571"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_8"
      decimals="2"
      id="ixv-572"
      unitRef="USD">20715.00</ffd:FeeAmt>
    <ffd:TtlOfferingAmt contextRef="rc" decimals="2" id="ixv-573" unitRef="USD">150000000.00</ffd:TtlOfferingAmt>
    <ffd:TtlFeeAmt contextRef="rc" decimals="2" id="ixv-574" unitRef="USD">20715.00</ffd:TtlFeeAmt>
    <ffd:TtlPrevslyPdAmt contextRef="rc" decimals="2" id="ixv-575" unitRef="USD">0.00</ffd:TtlPrevslyPdAmt>
    <ffd:TtlOffsetAmt contextRef="rc" decimals="2" id="ixv-576" unitRef="USD">0.00</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="rc" decimals="2" id="ixv-577" unitRef="USD">20715.00</ffd:NetFeeAmt>
    <ffd:OfferingNote contextRef="offrl_8" id="ixv-578">1 The amount registered is not specified as to each class of securities to be registered pursuant to Instructions 2.A.ii.b. and 2.A.iii.b. to the Calculation of Filing Fee Tables and Related Disclosure under Item 16(b) of Form S-3 under the Securities Act. The proposed maximum offering price per unit will be determined from time to time by the registrant in connection with the issuance by the registrant of the securities registered hereunder. The maximum aggregate offering price is estimated solely for the purpose of calculating the registration fee pursuant to Rule 457(o). 2 Each depositary share will be issued under a deposit agreement, will represent a fractional interest in shares of preferred stock or common stock and will be evidenced by a depositary receipt. 3 Purchase contracts may be sold separately or as parts of units consisting of common stock, preferred stock or depositary shares that are otherwise registered hereunder. 4 Consisting of some or all of the securities listed above, in any combination. 5 There is being registered hereunder an indeterminate number or amount of common stock, preferred stock, depositary shares, warrants, debt securities, purchase contracts and units, in each case as may periodically be offered at indeterminate prices, which together shall have a maximum aggregate offering price not to exceed $150,000,000. Separate consideration may or may not be received for any securities registered hereunder that are issued upon the exercise, conversion or exchange of, as the case may be, other securities registered hereunder.</ffd:OfferingNote>
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