<?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">0001508655</identifier>
        </entity>
        <period>
            <startDate>2026-11-09</startDate>
            <endDate>2026-11-09</endDate>
        </period>
    </context>
    <context id="offrl_1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001508655</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>1</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-11-09</startDate>
            <endDate>2026-11-09</endDate>
        </period>
    </context>
    <context id="offrl_2">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001508655</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>2</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-11-09</startDate>
            <endDate>2026-11-09</endDate>
        </period>
    </context>
    <context id="offrl_3">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001508655</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>3</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-11-09</startDate>
            <endDate>2026-11-09</endDate>
        </period>
    </context>
    <context id="offrl_4">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001508655</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>4</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-11-09</startDate>
            <endDate>2026-11-09</endDate>
        </period>
    </context>
    <context id="offrl_5">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001508655</identifier>
            <segment>
                <xbrldi:typedMember dimension="ffd:OfferingAxis">
                    <dei:lineNo>5</dei:lineNo>
                </xbrldi:typedMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-11-09</startDate>
            <endDate>2026-11-09</endDate>
        </period>
    </context>
    <unit id="USD">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="pure">
        <measure>pure</measure>
    </unit>
    <ffd:FormTp contextRef="rc" id="ixv-425">N-2</ffd:FormTp>
    <ffd:SubmissnTp contextRef="rc" id="ixv-426">N-2ASR</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="rc" id="ixv-427">EX-FILING FEES</ffd:FeeExhibitTp>
    <dei:EntityCentralIndexKey contextRef="rc" id="ixv-428">0001508655</dei:EntityCentralIndexKey>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-429">Sixth Street Specialty Lending, 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-493">N-2</ffd:FormTp>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-494">Sixth Street Specialty Lending, Inc.</dei:EntityRegistrantName>
    <ffd:PrevslyPdFlg contextRef="offrl_1" id="ixv-495">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_1" id="ixv-496">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_1" id="ixv-497">Common Stock, $0.01 par value per share</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_1" id="ixv-498">true</ffd:FeesOthrRuleFlg>
    <ffd:FeeRate
      contextRef="offrl_1"
      decimals="6"
      id="ixv-499"
      unitRef="pure">0.000087</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_1"
      decimals="2"
      id="ixv-500"
      unitRef="USD">0.00</ffd:FeeAmt>
    <ffd:PrevslyPdFlg contextRef="offrl_2" id="ixv-501">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_2" id="ixv-502">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_2" id="ixv-503">Preferred Stock, $0.01 par value per share</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_2" id="ixv-504">true</ffd:FeesOthrRuleFlg>
    <ffd:FeeRate
      contextRef="offrl_2"
      decimals="6"
      id="ixv-505"
      unitRef="pure">0.000087</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_2"
      decimals="2"
      id="ixv-506"
      unitRef="USD">0.00</ffd:FeeAmt>
    <ffd:PrevslyPdFlg contextRef="offrl_3" id="ixv-507">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_3" id="ixv-508">Other</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_3" id="ixv-509">Subscription Rights</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_3" id="ixv-510">true</ffd:FeesOthrRuleFlg>
    <ffd:FeeRate
      contextRef="offrl_3"
      decimals="6"
      id="ixv-511"
      unitRef="pure">0.000087</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_3"
      decimals="2"
      id="ixv-512"
      unitRef="USD">0.00</ffd:FeeAmt>
    <ffd:PrevslyPdFlg contextRef="offrl_4" id="ixv-513">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_4" id="ixv-514">Other</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_4" id="ixv-515">Warrants</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_4" id="ixv-516">true</ffd:FeesOthrRuleFlg>
    <ffd:FeeRate
      contextRef="offrl_4"
      decimals="6"
      id="ixv-517"
      unitRef="pure">0.000087</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_4"
      decimals="2"
      id="ixv-518"
      unitRef="USD">0.00</ffd:FeeAmt>
    <ffd:PrevslyPdFlg contextRef="offrl_5" id="ixv-519">false</ffd:PrevslyPdFlg>
    <ffd:OfferingSctyTp contextRef="offrl_5" id="ixv-520">Other</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_5" id="ixv-521">Debt Securities</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_5" id="ixv-522">true</ffd:FeesOthrRuleFlg>
    <ffd:FeeRate
      contextRef="offrl_5"
      decimals="6"
      id="ixv-523"
      unitRef="pure">0.000087</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_5"
      decimals="2"
      id="ixv-524"
      unitRef="USD">0.00</ffd:FeeAmt>
    <ffd:TtlOfferingAmt contextRef="rc" decimals="2" id="ixv-525" unitRef="USD">0.00</ffd:TtlOfferingAmt>
    <ffd:TtlFeeAmt contextRef="rc" decimals="2" id="ixv-526" unitRef="USD">0.00</ffd:TtlFeeAmt>
    <ffd:TtlPrevslyPdAmt contextRef="rc" decimals="2" id="ixv-527" unitRef="USD">0.00</ffd:TtlPrevslyPdAmt>
    <ffd:TtlOffsetAmt contextRef="rc" decimals="2" id="ixv-528" unitRef="USD">0.00</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="rc" decimals="2" id="ixv-529" unitRef="USD">0.00</ffd:NetFeeAmt>
    <ffd:OfferingNote contextRef="offrl_1" id="ixv-530">(1) An unspecified amount of securities or aggregate principal amount, as applicable, of each identified class is being registered as may from time to time be sold at unspecified prices. (2) In accordance with Rules 456(b), 457(r) and 415(a)(6) promulgated under the Securities Act, the Registrant is deferring payment of all of the registration fees. Registration fees will be paid subsequently on a pay-as-you-go basis. (3) There is being registered hereunder an indeterminate number of shares of common stock or preferred stock, or subscription rights to purchase shares of common stock as may be sold, from time to time. (4) Includes such indeterminate number of shares of common stock, preferred stock or debt securities as may, from time to time, be issued upon conversion or exchange of other securities registered hereunder, to the extent any such securities are, by their terms, convertible or exchangeable for common stock, preferred stock or debt securities. </ffd:OfferingNote>
    <ffd:OfferingNote contextRef="offrl_2" id="ixv-531">(1) An unspecified amount of securities or aggregate principal amount, as applicable, of each identified class is being registered as may from time to time be sold at unspecified prices. (2) In accordance with Rules 456(b), 457(r) and 415(a)(6) promulgated under the Securities Act, the Registrant is deferring payment of all of the registration fees. Registration fees will be paid subsequently on a pay-as-you-go basis. (3) There is being registered hereunder an indeterminate number of shares of common stock or preferred stock, or subscription rights to purchase shares of common stock as may be sold, from time to time. (4) Includes such indeterminate number of shares of common stock, preferred stock or debt securities as may, from time to time, be issued upon conversion or exchange of other securities registered hereunder, to the extent any such securities are, by their terms, convertible or exchangeable for common stock, preferred stock or debt securities. </ffd:OfferingNote>
    <ffd:OfferingNote contextRef="offrl_3" id="ixv-532">(1) An unspecified amount of securities or aggregate principal amount, as applicable, of each identified class is being registered as may from time to time be sold at unspecified prices. (2) In accordance with Rules 456(b), 457(r) and 415(a)(6) promulgated under the Securities Act, the Registrant is deferring payment of all of the registration fees. Registration fees will be paid subsequently on a pay-as-you-go basis. (3) There is being registered hereunder an indeterminate number of shares of common stock or preferred stock, or subscription rights to purchase shares of common stock as may be sold, from time to time.</ffd:OfferingNote>
    <ffd:OfferingNote contextRef="offrl_4" id="ixv-533">(1) An unspecified amount of securities or aggregate principal amount, as applicable, of each identified class is being registered as may from time to time be sold at unspecified prices. (2) In accordance with Rules 456(b), 457(r) and 415(a)(6) promulgated under the Securities Act, the Registrant is deferring payment of all of the registration fees. Registration fees will be paid subsequently on a pay-as-you-go basis. (5) There is being registered hereunder an indeterminate number of warrants as may be sold, from time to time, representing rights to purchase common stock, preferred stock or debt securities. </ffd:OfferingNote>
    <ffd:OfferingNote contextRef="offrl_5" id="ixv-534">(1) An unspecified amount of securities or aggregate principal amount, as applicable, of each identified class is being registered as may from time to time be sold at unspecified prices. (2) In accordance with Rules 456(b), 457(r) and 415(a)(6) promulgated under the Securities Act, the Registrant is deferring payment of all of the registration fees. Registration fees will be paid subsequently on a pay-as-you-go basis. (4) Includes such indeterminate number of shares of common stock, preferred stock or debt securities as may, from time to time, be issued upon conversion or exchange of other securities registered hereunder, to the extent any such securities are, by their terms, convertible or exchangeable for common stock, preferred stock or debt securities. (6) There is being registered hereunder an indeterminate principal amount of debt securities as may be sold, from time to time. </ffd:OfferingNote>
</xbrl>
