<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Version>2.3.0.15</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ReportType />
  <ContextCount>119</ContextCount>
  <ElementCount>205</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>30</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>true</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001500 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/ConsolidatedStatementsOfOperations</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1002500 - Statement - Consolidated Statements of Operations (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/ConsolidatedStatementsOfOperationsParenthetical</Role>
      <ShortName>Consolidated Statements of Operations (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1003000 - Statement - Consolidated Statement of Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/ConsolidatedStatementOfEquity</Role>
      <ShortName>Consolidated Statement of Equity</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1004000 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Organization and Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/OrganizationAndBasisOfPresentation</Role>
      <ShortName>Organization and Basis of Presentation</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - Income per Common Share of the Trust</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/IncomePerCommonShareOfTrust</Role>
      <ShortName>Income per Common Share of the Trust</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2103100 - Disclosure - Income per Common Unit of the Operating Partnership</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/IncomePerCommonUnitOfOperatingPartnership</Role>
      <ShortName>Income per Common Unit of the Operating Partnership</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Other Comprehensive Income of the Trust</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/OtherComprehensiveIncomeOfTrust</Role>
      <ShortName>Other Comprehensive Income of the Trust</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - Other Comprehensive Income of the Operating Partnership</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/OtherComprehensiveIncomeOfOperatingPartnership</Role>
      <ShortName>Other Comprehensive Income of the Operating Partnership</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Accounting for the Impairment or Disposal of Long-Lived Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/AccountingForImpairmentOrDisposalOfLongLivedAssets</Role>
      <ShortName>Accounting for the Impairment or Disposal of Long-Lived Assets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Noncontrolling Interests</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/NoncontrollingInterests</Role>
      <ShortName>Noncontrolling Interests</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Limited Partners' Equity of the Operating Partnership</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/LimitedPartnersEquityOfOperatingPartnership</Role>
      <ShortName>Limited Partners' Equity of the Operating Partnership</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Indebtedness</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/Indebtedness</Role>
      <ShortName>Indebtedness</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - Disclosure of Fair Value of Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/DisclosureOfFairValueOfFinancialInstruments</Role>
      <ShortName>Disclosure of Fair Value of Financial Instruments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - Supplemental Disclosure to Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/SupplementalDisclosureToStatementsOfCashFlows</Role>
      <ShortName>Supplemental Disclosure to Statements of Cash Flows</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2115100 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2201201 - Disclosure - Organization and Basis of Presentation (Policy)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/OrganizationAndBasisOfPresentationPolicy</Role>
      <ShortName>Organization and Basis of Presentation (Policy)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2302302 - Disclosure - Income per Common Share of the Trust (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/IncomePerCommonShareOfTrustTables</Role>
      <ShortName>Income per Common Share of the Trust (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - Income per Common Unit of the Operating Partnership (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/IncomePerCommonUnitOfOperatingPartnershipTables</Role>
      <ShortName>Income per Common Unit of the Operating Partnership (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Accounting for the Impairment or Disposal of Long-Lived Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/AccountingForImpairmentOrDisposalOfLongLivedAssetsTables</Role>
      <ShortName>Accounting for the Impairment or Disposal of Long-Lived Assets (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - Noncontrolling Interests (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/NoncontrollingInterestsTables</Role>
      <ShortName>Noncontrolling Interests (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2309301 - Disclosure - Limited Partners' Equity of the Operating Partnership (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/LimitedPartnersEquityOfOperatingPartnershipTables</Role>
      <ShortName>Limited Partners' Equity of the Operating Partnership (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2313301 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/CommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2314301 - Disclosure - Supplemental Disclosure to Statements of Cash Flows (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/SupplementalDisclosureToStatementsOfCashFlowsTables</Role>
      <ShortName>Supplemental Disclosure to Statements of Cash Flows (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2401402 - Disclosure - Organization and Basis of Presentation (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/OrganizationAndBasisOfPresentationNarrativeDetails</Role>
      <ShortName>Organization and Basis of Presentation (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2402403 - Disclosure - Income per Common Share of the Trust (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/IncomePerCommonShareOfTrustNarrativeDetails</Role>
      <ShortName>Income per Common Share of the Trust (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2402404 - Disclosure - Income per Common Share of the Trust Income per Common Share of the Trust (Computation of Basic and Diluted Income Per Common Share) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/IncomePerCommonShareOfTrustIncomePerCommonShareOfTrustComputationOfBasicAndDilutedIncomePerCommonShareDetails</Role>
      <ShortName>Income per Common Share of the Trust Income per Common Share of the Trust (Computation of Basic and Diluted Income Per Common Share) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2403402 - Disclosure - Income per Common Unit of the Operating Partnership (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/IncomePerCommonUnitOfOperatingPartnershipDetails</Role>
      <ShortName>Income per Common Unit of the Operating Partnership (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - Other Comprehensive Income of the Trust (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/OtherComprehensiveIncomeOfTrustDetails</Role>
      <ShortName>Other Comprehensive Income of the Trust (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2405401 - Disclosure - Other Comprehensive Income of the Operating Partnership (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/OtherComprehensiveIncomeOfOperatingPartnershipDetails</Role>
      <ShortName>Other Comprehensive Income of the Operating Partnership (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - Segment Information (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/SegmentInformationNarrativeDetails</Role>
      <ShortName>Segment Information (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2406404 - Disclosure - Segment Information (Performance of the Reportable Segments Based on Property Level Operating Income) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/SegmentInformationPerformanceOfReportableSegmentsBasedOnPropertyLevelOperatingIncomeDetails</Role>
      <ShortName>Segment Information (Performance of the Reportable Segments Based on Property Level Operating Income) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Accounting for the Impairment or Disposal of Long-Lived Assets (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/AccountingForImpairmentOrDisposalOfLongLivedAssetsNarrativeDetails</Role>
      <ShortName>Accounting for the Impairment or Disposal of Long-Lived Assets (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Accounting for the Impairment or Disposal of Long-Lived Assets (Results of Operations for the Properties Held for Sale and Disposed) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/AccountingForImpairmentOrDisposalOfLongLivedAssetsResultsOfOperationsForPropertiesHeldForSaleAndDisposedDetails</Role>
      <ShortName>Accounting for the Impairment or Disposal of Long-Lived Assets (Results of Operations for the Properties Held for Sale and Disposed) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Noncontrolling Interests (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/NoncontrollingInterestsNarrativeDetails</Role>
      <ShortName>Noncontrolling Interests (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Noncontrolling Interests (Outstanding Cumulative Redeemable Preferred Units) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/NoncontrollingInterestsOutstandingCumulativeRedeemablePreferredUnitsDetails</Role>
      <ShortName>Noncontrolling Interests (Outstanding Cumulative Redeemable Preferred Units) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2409402 - Disclosure - Limited Partners' Equity of the Operating Partnership Limited Partners' Equity of the Operating Partnership (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/LimitedPartnersEquityOfOperatingPartnershipLimitedPartnersEquityOfOperatingPartnershipDetails</Role>
      <ShortName>Limited Partners' Equity of the Operating Partnership Limited Partners' Equity of the Operating Partnership (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2410401 - Disclosure - Indebtedness (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/IndebtednessDetails</Role>
      <ShortName>Indebtedness (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2412401 - Disclosure - Disclosure of Fair Value of Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/DisclosureOfFairValueOfFinancialInstrumentsDetails</Role>
      <ShortName>Disclosure of Fair Value of Financial Instruments (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2413402 - Disclosure - Commitments and Contingencies (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/CommitmentsAndContingenciesNarrativeDetails</Role>
      <ShortName>Commitments and Contingencies (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2413403 - Disclosure - Commitments and Contingencies (Future Minimum Rental Payments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/CommitmentsAndContingenciesFutureMinimumRentalPaymentsDetails</Role>
      <ShortName>Commitments and Contingencies (Future Minimum Rental Payments) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2414402 - Disclosure - Supplemental Disclosure to Statements of Cash Flows (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/SupplementalDisclosureToStatementsOfCashFlowsDetails</Role>
      <ShortName>Supplemental Disclosure to Statements of Cash Flows (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2415402 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.libertyproperty.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Info">Element lry_AmortizedCostOnDeferredFinancingAndLeasingCosts had a mix of decimals attribute values: 0 -3.</Log>
    <Log type="Info">Element us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPeriodIncreaseDecrease had a mix of decimals attribute values: -3 -5.</Log>
    <Log type="Info">Element us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPeriodIncreaseDecrease had a mix of decimals attribute values: -3 -5.</Log>
    <Log type="Info">Element us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPeriodIncreaseDecrease had a mix of decimals attribute values: -3 -5.</Log>
    <Log type="Info">'Shares' elements on report '2403402 - Disclosure - Income per Common Unit of the Operating Partnership (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '2404402 - Disclosure - Other Comprehensive Income of the Trust (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '2405401 - Disclosure - Other Comprehensive Income of the Operating Partnership (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '2407402 - Disclosure - Accounting for the Impairment or Disposal of Long-Lived Assets (Narrative) (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '2408403 - Disclosure - Noncontrolling Interests (Outstanding Cumulative Redeemable Preferred Units) (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '2409402 - Disclosure - Limited Partners' Equity of the Operating Partnership Limited Partners' Equity of the Operating Partnership (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">Process Flow-Through: 1001000 - Statement - Consolidated Balance Sheets</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Sep. 30, 2010'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2009'</Log>
    <Log type="Info">Process Flow-Through: 1001500 - Statement - Consolidated Balance Sheets (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 1002000 - Statement - Consolidated Statements of Operations</Log>
    <Log type="Info">Process Flow-Through: 1002500 - Statement - Consolidated Statements of Operations (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 1004000 - Statement - Consolidated Statements of Cash Flows</Log>
  </Logs>
  <InputFiles>
    <File>lry-20110930.xml</File>
    <File>lry-20110930.xsd</File>
    <File>lry-20110930_cal.xml</File>
    <File>lry-20110930_def.xml</File>
    <File>lry-20110930_lab.xml</File>
    <File>lry-20110930_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
