2.4.0.82201201 - Disclosure - Organization and Basis of Presentation (Policy)truefalsefalse1false falsefalseD2013Q2YTDhttp://www.sec.gov/CIK0000921112duration2013-01-01T00:00:002013-06-30T00:00:001true 1lry_OrganizationAndBasisOfPresentationAbstractlry_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization and Basis of Presentation [Abstract]2false 2lry_OrganizationPolicyTextBlocklry_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;padding-top:6px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-weight:bold;">Organization</font></div><div style="line-height:120%;padding-top:6px;text-align:justify;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">Liberty Property Trust (the “Trust”) is a self-administered and self-managed Maryland real estate investment trust (a “REIT”). Substantially all of the Trust’s assets are owned directly or indirectly, and substantially all of the Trust’s operations are conducted directly or indirectly, by its subsidiary, Liberty Property Limited Partnership, a Pennsylvania limited partnership (the “Operating Partnership” and, together with the Trust and their consolidated subsidiaries, the “Company”). The Trust is the sole general partner and also a limited partner of the Operating Partnership, owning </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">97.0%</font><font style="font-family:inherit;font-size:10pt;"> of the common equity of the Operating Partnership at </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">June 30, 2013</font><font style="font-family:inherit;font-size:10pt;">. The Company provides leasing, property management, development, acquisition, and other tenant-related services for a portfolio of industrial and office properties which are located principally within the Mid-Atlantic, Southeastern, Midwestern and Southwestern United States and the United Kingdom. Unless otherwise indicated, the notes to the Consolidated Financial Statements apply to both the Trust and the Operating Partnership. The terms the "Company,” “we,” “our” and “us” mean the Trust and Operating Partnership collectively.</font></div></div>falsefalsefalsenonnum:textBlockItemTypenaOrganization Policy.No definition available.false0Organization3false 2lry_BasisOfPresentationPolicyTextBlocklry_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;padding-top:18px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-weight:bold;">Basis of Presentation</font></div><div style="line-height:120%;padding-top:6px;text-align:justify;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">The accompanying unaudited consolidated financial statements of the Company have been prepared in accordance with United States generally accepted accounting principles (“US GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements and should be read in conjunction with the consolidated financial statements and notes thereto included in the Annual Report on Form 10-K of the Company for the year ended </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">December 31, 2012</font><font style="font-family:inherit;font-size:10pt;">. In the opinion of management, all adjustments (consisting solely of normal recurring adjustments) necessary for a fair presentation of the financial statements for these interim periods have been included. The results of interim periods are not necessarily indicative of the results to be obtained for a full fiscal year. Certain amounts from prior periods have been reclassified to conform to the current period presentation including reclassifying the accompanying consolidated balance sheets and statements of comprehensive income for assets held for sale and discontinued operations.</font></div></div>falsefalsefalsenonnum:textBlockItemTypenaBasis Of Presentation Policy.No definition available.false0Basis of Presentation4false 2us-gaap_ConsolidationVariableInterestEntityPolicyus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;padding-top:18px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-weight:bold;">Principles of Consolidation</font></div><div style="line-height:120%;padding-top:6px;text-align:justify;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">When the Company obtains an economic interest in an entity, the Company evaluates the entity to determine if the entity is deemed a variable interest entity (“VIE”).  If the entity is deemed a VIE, the Company then determines if the Company is deemed to be the primary beneficiary. The accounting standard for the consolidation of VIEs requires the Company to qualitatively assess if the Company was the primary beneficiary of the VIEs based on whether the Company had (i) the power to direct those matters that most significantly impacted the activities of the VIE and (ii) the obligation to absorb losses or the right to receive benefits of the VIE that could potentially be significant to the VIE. </font></div><div style="line-height:120%;padding-top:6px;text-align:justify;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">The Company continuously assesses its determination of whether it is the primary beneficiary of a VIE, and whether or not the limited partners in an entity have substantive rights, more particularly if certain events occur that are likely to cause a change in the original determinations. The Company's assessment includes a review of applicable documents such as, but not limited to, applicable partnership agreements and management and leasing agreements to determine whether the Company has the ability to direct the business activities of the entities. The portion of the consolidated entities that is not owned by the Company is presented as non-controlling interest as of and during the periods consolidated. All intercompany accounts and transactions have been eliminated in consolidation. </font></div></div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for consolidation to describe the significant judgments and assumptions made in determining whether a variable interest held by the entity requires the variable interest entity to be consolidated and (or) disclose information about its involvement with the variable interest entity; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; and the significant factors considered and judgments made in determining that the power to direct the activities that significantly impact the economic performance of the variable interest entity are shared (as defined).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -URI http://asc.fasb.org/subtopic&trid=2197480 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 46R -Paragraph 14, 15 -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. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=7880789&loc=SL6759159-111685 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=7880789&loc=d3e5728-111685 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 2AA -Subparagraph a -URI http://asc.fasb.org/extlink&oid=7880789&loc=SL6759068-111685 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 167 -Paragraph 24 -Subparagraph e -Appendix D Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 167 -Paragraph 22E -Subparagraph a -Appendix D Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 167 -Paragraph 22B -Subparagraph a -Appendix D false0Consolidation, Variable Interest Entity, Policy [Policy Text Block]falseOrganization and Basis of Presentation (Policy)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.libertyproperty.com/role/OrganizationAndBasisOfPresentationPolicy14