2.4.0.82408401 - Disclosure - Investments in Unconsolidated Joint Ventures Investments in Unconsoidated Joint Ventures (Details)truefalseIn Thousands, unless otherwise specifiedfalse1false USDfalsefalse$I2013Q2http://www.sec.gov/CIK0000921112instant2013-06-30T00:00:000001-01-01T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$I2012Q4http://www.sec.gov/CIK0000921112instant2012-12-31T00:00:000001-01-01T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3us-gaap_ScheduleOfEquityMethodInvestmentsLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Equity Method Investments [Line Items]2false 4us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVenturesus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse175314000175314USD$falsetruefalse2truefalsefalse169021000169021USD$falsetruefalsexbrli:monetaryItemTypemonetaryTotal investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures3false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3false USDtruefalse$I2012Q4_us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lry_BlytheValleyJvSarlMemberhttp://www.sec.gov/CIK0000921112instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseBlythe Valley JV Sarl [Member]us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxisxbrldihttp://xbrl.org/2006/xbrldilry_BlytheValleyJvSarlMemberus-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Blythe Valley JV Sarl [Member]4true 3us-gaap_ScheduleOfEquityMethodInvestmentsLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Equity Method Investments [Line Items]5false 4us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVenturesus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse00USD$falsetruefalsexbrli:monetaryItemTypemonetaryTotal investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint VenturesfalseInvestments in Unconsolidated Joint Ventures Investments in Unconsoidated Joint Ventures (Details) (USD $)ThousandsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.libertyproperty.com/role/InvestmentsInUnconsolidatedJointVenturesInvestmentsInUnconsoidatedJointVenturesDetails25