2.4.0.82108100 - Disclosure - Investments in Unconsolidated Joint Ventures Investments in Unconsolidated Joint Ventures (Notes)truefalsefalse1false falsefalseD2013Q2YTDhttp://www.sec.gov/CIK0000921112duration2013-01-01T00:00:002013-06-30T00:00:001true 1us-gaap_EquityMethodInvestmentsAndJointVenturesAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Equity Method Investments and Joint Ventures [Abstract]2false 2us-gaap_EquityMethodInvestmentsDisclosureTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-weight:bold;text-decoration:underline;"> Investments in Unconsolidated Joint Ventures</font></div><div style="line-height:120%;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"><br clear="none"/></font></div><div style="line-height:120%;text-align:justify;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">In October 2012, Blythe Valley JV Sarl, a joint venture in which the Company held an interest, defaulted on its mortgage loan. The mortgage loan was secured by all of the operating properties and land of the joint venture. During the three months ended March 31, 2013, the lender appointed a receiver, effectively taking control of the assets securing its loan. During the year ended December 31, 2012 the joint venture recorded an impairment charge, the Company's share of which was sufficient to bring the Company's investment in the joint venture to </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">zero</font><font style="font-family:inherit;font-size:10pt;">.</font></div></div>falsefalsefalsenonnum:textBlockItemTypenaThe entire disclosure for equity method investments and joint ventures. Equity method investments are investments that give the investor the ability to exercise significant influence over the operating and financial policies of an investee. Joint ventures are entities owned and operated by a small group of businesses as a separate and specific business or project for the mutual benefit of the members of the group.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 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 35 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=7658923&loc=d3e32847-111569 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 35 -Paragraph 32 -URI http://asc.fasb.org/extlink&oid=7658923&loc=d3e32787-111569 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 18 -Paragraph 20 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false0Equity Method Investments and Joint Ventures Disclosure [Text Block]falseInvestments in Unconsolidated Joint Ventures Investments in Unconsolidated Joint Ventures (Notes)UnKnownUnKnownUnKnownUnKnowntruefalsefalseNoteshttp://www.libertyproperty.com/role/InvestmentsInUnconsolidatedJointVenturesInvestmentsInUnconsolidatedJointVenturesNotes12