<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.23.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>21</ContextCount>
  <ElementCount>87</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>18</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>2</UnitCount>
  <MyReports>
    <Report instance="d674432d485bpos.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000000 - Document - Document and Entity Information {Elements}</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.leggmason.com/role/DocumentDocumentandEntityInformationElements000000</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory></MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="d674432d485bpos.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>000021 - Disclosure - Risk/Return Detail Data {Elements} - ClearBridge Large Cap Growth Fund</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.leggmason.com/role/DisclosureRiskReturnDetailDataElementsClearBridgeLargeCapGrowthFund000021</Role>
      <ShortName>Risk/Return Detail Data- ClearBridge Large Cap Growth Fund</ShortName>
      <MenuCategory></MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="d674432d485bpos.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>000041 - Disclosure - Risk/Return Detail Data {Elements} - Franklin U.S. Large Cap Equity Fund</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.leggmason.com/role/DisclosureRiskReturnDetailDataElementsFranklinU.S.LargeCapEquityFund000041</Role>
      <ShortName>Risk/Return Detail Data- Franklin U.S. Large Cap Equity Fund</ShortName>
      <MenuCategory></MenuCategory>
      <Position>3</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept RiskNarrativeTextBlock in rr/2021 used in 2 facts was deprecated in rr/2023 as of 2023-01-31 and should not be used. d674432d485bpos.htm 604, 7111</Log>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept RiskLoseMoney in rr/2021 used in 2 facts was deprecated in rr/2023 as of 2023-01-31 and should not be used. d674432d485bpos.htm 604, 7111</Log>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept RiskNotInsuredDepositoryInstitution in rr/2021 used in 2 facts was deprecated in rr/2023 as of 2023-01-31 and should not be used. d674432d485bpos.htm 604, 7111</Log>
    <Log type="Warning">[ix-0514-Hidden-Fact-Eligible-For-Transform] WARN: 2 fact(s) appearing in ix:hidden were eligible for transformation: rr:RiskReturnHeading -  d674432d485bpos.htm 7</Log>
  </Logs>
  <InputFiles>
    <File doctype="485BPOS" original="d674432d485bpos.htm">d674432d485bpos.htm</File>
    <File>d674432dex99j.htm</File>
    <File>lmpet-20230324.xsd</File>
    <File>lmpet-20230324_cal.xml</File>
    <File>lmpet-20230324_def.xml</File>
    <File>lmpet-20230324_lab.xml</File>
    <File>lmpet-20230324_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>g674432clearbridgelogo.jpg</File>
    <File>g674432dsp008.jpg</File>
    <File>g674432g1g03p97.jpg</File>
    <File>g674432g1g83h05.jpg</File>
    <File>g674432g1sp006.jpg</File>
    <File>g674432g57q58.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="8">http://xbrl.sec.gov/dei/2021</BaseTaxonomy>
    <BaseTaxonomy items="354">http://xbrl.sec.gov/rr/2021</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
