<?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">0001829802</identifier>
        </entity>
        <period>
            <startDate>2026-06-18</startDate>
            <endDate>2026-06-18</endDate>
        </period>
    </context>
    <context id="offrl_1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001829802</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>1</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-06-18</startDate>
            <endDate>2026-06-18</endDate>
        </period>
    </context>
    <context id="offrl_2">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001829802</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>2</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-06-18</startDate>
            <endDate>2026-06-18</endDate>
        </period>
    </context>
    <context id="offrl_3">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001829802</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>3</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-06-18</startDate>
            <endDate>2026-06-18</endDate>
        </period>
    </context>
    <context id="offrl_4">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001829802</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>4</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-06-18</startDate>
            <endDate>2026-06-18</endDate>
        </period>
    </context>
    <context id="offrl_5">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001829802</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>5</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-06-18</startDate>
            <endDate>2026-06-18</endDate>
        </period>
    </context>
    <unit id="USD">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="pure">
        <measure>pure</measure>
    </unit>
    <ffd:FormTp contextRef="rc" id="ixv-426">S-3</ffd:FormTp>
    <ffd:SubmissnTp contextRef="rc" id="ixv-427">S-3ASR</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="rc" id="ixv-428">EX-FILING FEES</ffd:FeeExhibitTp>
    <dei:EntityCentralIndexKey contextRef="rc" id="ixv-429">0001829802</dei:EntityCentralIndexKey>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-430">Faeth Therapeutics, Inc.</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>
    <ffd:FormTp contextRef="rc" id="ixv-494">S-3</ffd:FormTp>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-495">Faeth Therapeutics, Inc.</dei:EntityRegistrantName>
    <ffd:PrevslyPdFlg contextRef="offrl_1" id="ixv-496">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_1" id="ixv-497">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_1" id="ixv-498">Common Stock, $0.0001 par value per share</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_1" id="ixv-499">true</ffd:FeesOthrRuleFlg>
    <ffd:FeeRate
      contextRef="offrl_1"
      decimals="7"
      id="ixv-500"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_1"
      decimals="2"
      id="ixv-501"
      unitRef="USD">0.00</ffd:FeeAmt>
    <ffd:PrevslyPdFlg contextRef="offrl_2" id="ixv-502">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_2" id="ixv-503">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_2" id="ixv-504">Preferred Stock, $0.0001 par value per share</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_2" id="ixv-505">true</ffd:FeesOthrRuleFlg>
    <ffd:FeeRate
      contextRef="offrl_2"
      decimals="7"
      id="ixv-506"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_2"
      decimals="2"
      id="ixv-507"
      unitRef="USD">0.00</ffd:FeeAmt>
    <ffd:PrevslyPdFlg contextRef="offrl_3" id="ixv-508">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_3" id="ixv-509">Debt</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_3" id="ixv-510">Debt Securities</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_3" id="ixv-511">true</ffd:FeesOthrRuleFlg>
    <ffd:FeeRate
      contextRef="offrl_3"
      decimals="7"
      id="ixv-512"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_3"
      decimals="2"
      id="ixv-513"
      unitRef="USD">0.00</ffd:FeeAmt>
    <ffd:PrevslyPdFlg contextRef="offrl_4" id="ixv-514">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_4" id="ixv-515">Other</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_4" id="ixv-516">Warrants</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_4" id="ixv-517">true</ffd:FeesOthrRuleFlg>
    <ffd:FeeRate
      contextRef="offrl_4"
      decimals="7"
      id="ixv-518"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_4"
      decimals="2"
      id="ixv-519"
      unitRef="USD">0.00</ffd:FeeAmt>
    <ffd:PrevslyPdFlg contextRef="offrl_5" id="ixv-520">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_5" id="ixv-521">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_5" id="ixv-522">Common Stock, $0.0001 par value per share</ffd:OfferingSctyTitl>
    <ffd:Rule457oFlg contextRef="offrl_5" id="ixv-523">true</ffd:Rule457oFlg>
    <ffd:MaxAggtOfferingPric
      contextRef="offrl_5"
      decimals="2"
      id="ixv-524"
      unitRef="USD">150000000.00</ffd:MaxAggtOfferingPric>
    <ffd:FeeRate
      contextRef="offrl_5"
      decimals="7"
      id="ixv-525"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_5"
      decimals="2"
      id="ixv-526"
      unitRef="USD">20715.00</ffd:FeeAmt>
    <ffd:TtlOfferingAmt contextRef="rc" decimals="2" id="ixv-527" unitRef="USD">150000000.00</ffd:TtlOfferingAmt>
    <ffd:TtlFeeAmt contextRef="rc" decimals="2" id="ixv-528" unitRef="USD">20715.00</ffd:TtlFeeAmt>
    <ffd:TtlPrevslyPdAmt contextRef="rc" decimals="2" id="ixv-529" unitRef="USD">0.00</ffd:TtlPrevslyPdAmt>
    <ffd:TtlOffsetAmt contextRef="rc" decimals="2" id="ixv-530" unitRef="USD">0.00</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="rc" decimals="2" id="ixv-531" unitRef="USD">20715.00</ffd:NetFeeAmt>
    <ffd:OfferingNote contextRef="offrl_1" id="ixv-532">The registrant is registering hereby an unspecified principal amount or number and offering price of securities of each identified class as may be offered, from time to time, hereunder, along with an indeterminate principal amount or number of securities that may be issued upon exercise, settlement, exchange or conversion of securities offered or sold hereunder. Separate consideration may or may not be received for securities that are issued upon conversion, exercise or exchange of other securities. The proposed maximum aggregate offering price per class of security will be determined from time to time by the registrant in connection with the issuance by the registrant of the securities registered hereunder and is not specified as to each class of security pursuant to General Instruction II.D of Form S-3 under the Securities Act. Any securities registered hereunder may be sold separately or as units with other securities registered hereunder. In accordance with Rule 456(b) and 457(r) under the Securities Act, the registrant is deferring payment of all registration fees other than the registration fee due in connection with $150,000,000 of shares of common stock that may be issued and sold from time to time under the sale agreement prospectus contained in this registration statement. Any subsequent registration fees will be paid on a pay-as-you-go basis.</ffd:OfferingNote>
    <ffd:OfferingNote contextRef="offrl_2" id="ixv-533">See Offering Note 1.</ffd:OfferingNote>
    <ffd:OfferingNote contextRef="offrl_3" id="ixv-534">See Offering Note 1.</ffd:OfferingNote>
    <ffd:OfferingNote contextRef="offrl_4" id="ixv-535">See Offering Note 1.</ffd:OfferingNote>
    <ffd:OfferingNote contextRef="offrl_5" id="ixv-536">The registration fee is calculated in accordance with Rule 457(o) under the Securities Act, base on the proposed maximum aggregate offering price.</ffd:OfferingNote>
</xbrl>
