3.21.1 html 21 182 1 true 18 0 false 2 false false R1.htm 0001 - Document - Document and Entity Information {Elements} Sheet http://www.leggmason.com/role/DocumentAndEntityInformationElements Document and Entity Information 1 false true R2.htm 0002 - Document - Risk/Return Summary {Unlabeled} - ClearBridge Large Cap Growth Fund Sheet http://www.leggmason.com/role/RiskReturnSummaryUnlabeledClearbridgeLargeCapGrowthFund Risk/Return Summary- ClearBridge Large Cap Growth Fund 2 false false R9.htm 0009 - Disclosure - Risk/Return Detail Data {Elements} - ClearBridge Large Cap Growth Fund Sheet http://www.leggmason.com/role/RiskReturnDetailDataElementsClearbridgeLargeCapGrowthFund Risk/Return Detail Data- ClearBridge Large Cap Growth Fund 3 false true R10.htm 0010 - Document - Risk/Return Summary {Unlabeled} - QS U.S. Large Cap Equity Fund Sheet http://www.leggmason.com/role/RiskReturnSummaryUnlabeledQsUSLargeCapEquityFund Risk/Return Summary- QS U.S. Large Cap Equity Fund 4 false false R17.htm 0017 - Disclosure - Risk/Return Detail Data {Elements} - QS U.S. Large Cap Equity Fund Sheet http://www.leggmason.com/role/RiskReturnDetailDataElementsQsUSLargeCapEquityFund Risk/Return Detail Data- QS U.S. Large Cap Equity Fund 5 false false R18.htm 040000 - Disclosure - Risk/Return Detail Data {Elements} Sheet http://xbrl.sec.gov/rr/role/RiskReturnDetailData Risk/Return Detail Data 6 false false All Reports Book All Reports d110553d485bpos.htm d110553dex99j.htm d110553dex99o.htm lmpet-20211130.xsd lmpet-20211130_cal.xml lmpet-20211130_def.xml lmpet-20211130_lab.xml lmpet-20211130_pre.xml g110553g0318063501781.jpg g110553g0318063501968.jpg g110553g03p97.jpg g110553g1dsp006.jpg g110553g1g03p97.jpg g110553g1g83h05.jpg g110553g1qslogo.jpg g110553g71g95.jpg BarChart1.png BarChart2.png http://xbrl.sec.gov/dei/2020-01-31 http://xbrl.sec.gov/rr/2018-01-31 true true