2.2.0.25truefalse0207 - Disclosure - Disclosure of Fair Value of Financial Instrumentstruefalsefalse1falsefalseUSDfalsefalse1/1/2011 - 3/31/2011 USD ($) USD ($) / shares $Jan-01-2011_Mar-31-2011http://www.sec.gov/CIK0000921112duration2011-01-01T00:00:002011-03-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDEPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2false0us-gaap_FairValueDisclosuresTextBlockus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00  <div style="font-family: Helvetica,Arial,sans-serif; margin-left: 0in; "> <div align="justify" style="font-size: 10pt; margin-top: 10pt"><u><b>Note 6: Disclosure of Fair Value of Financial Instruments</b></u> </div> <div align="justify" style="font-size: 10pt; margin-top: 10pt">The following disclosure of estimated fair value was determined by management using available market information and appropriate valuation methodologies. However, considerable judgment is necessary to interpret market data and develop estimated fair value. Accordingly, the following estimates are not necessarily indicative of the amounts the Company could have realized on disposition of the financial instruments at March 31, 2011 and December 31, 2010. The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts. </div> <div align="justify" style="font-size: 10pt; margin-top: 10pt">The carrying value of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accrued interest, dividends and distributions payable and other liabilities are reasonable estimates of fair value because of the short-term nature of these instruments. The fair value of the Company’s long-term debt was greater than the aggregate carrying value by approximately $146.3 million and $189.0 million at March 31, 2011 and December 31, 2010, respectively. The fair value of the Company’s long-term debt is estimated using actual trading prices (where available) and using discounted cash flow analysis based on the borrowing rates currently available to the Company for loans with similar terms and maturities where actual trading prices are not available. </div> <div align="justify" style="font-size: 10pt; margin-top: 10pt">Disclosure about fair value of financial instruments is based on pertinent information available to management as of March 31, 2011 and December 31, 2010. Although as of the date of this report, management is not aware of any factors that would significantly affect the fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since March 31, 2011 and current estimates of fair value may differ significantly from the amounts presented herein. </div> </div> falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis item represents the complete disclosure regarding the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments, assets, and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the Company is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risk is are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 15B -Subparagraph a, b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 3, 10, 14, 15 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44A, 44B Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32, 33, 34 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 15C, 15D Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 15A -Subparagraph a-d Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 159 -Paragraph 17-22, 27, 28 falsefalseDisclosure of Fair Value of Financial Instruments3false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://libertyproperty.com/role/disclosureoffairvalueoffinancialinstruments1falsefalsefalse00falsefalsefalsefalsefalse2falsefalseUSDtruefalse{dei_LegalEntityAxis} : Limited Partnership [Member] 1/1/2011 - 3/31/2011 USD ($) USD ($) / shares $ThreeMonthsEnded_31Mar2011_Limited_Partnership_Memberhttp://www.sec.gov/CIK0000921112duration2011-01-01T00:00:002011-03-31T00:00:00falsefalseLIBERTY PROPERTY LIMITED PARTNERSHIPdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldilry_LimitedPartnershipMemberdei_LegalEntityAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDEPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseLIBERTY PROPERTY LIMITED PARTNERSHIP4false0us-gaap_FairValueDisclosuresTextBlockus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00  <div style="font-family: Helvetica,Arial,sans-serif; margin-left: 0in; "> <div align="justify" style="font-size: 10pt; margin-top: 10pt"><u><b>Note 6: Disclosure of Fair Value of Financial Instruments</b></u> </div> <div align="justify" style="font-size: 10pt; margin-top: 10pt">The following disclosure of estimated fair value was determined by management using available market information and appropriate valuation methodologies. However, considerable judgment is necessary to interpret market data and develop estimated fair value. Accordingly, the following estimates are not necessarily indicative of the amounts the Company could have realized on disposition of the financial instruments at March 31, 2011 and December 31, 2010. The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts. </div> <div align="justify" style="font-size: 10pt; margin-top: 10pt">The carrying value of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accrued interest, dividends and distributions payable and other liabilities are reasonable estimates of fair value because of the short-term nature of these instruments. The fair value of the Company’s long-term debt was greater than the aggregate carrying value by approximately $146.3 million and $189.0 million at March 31, 2011 and December 31, 2010, respectively. The fair value of the Company’s long-term debt is estimated using actual trading prices (where available) and using discounted cash flow analysis based on the borrowing rates currently available to the Company for loans with similar terms and maturities where actual trading prices are not available. </div> <div align="justify" style="font-size: 10pt; margin-top: 10pt">Disclosure about fair value of financial instruments is based on pertinent information available to management as of March 31, 2011 and December 31, 2010. Although as of the date of this report, management is not aware of any factors that would significantly affect the fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since March 31, 2011 and current estimates of fair value may differ significantly from the amounts presented herein. </div> </div> falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis item represents the complete disclosure regarding the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments, assets, and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the Company is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risk is are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 15B -Subparagraph a, b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 3, 10, 14, 15 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44A, 44B Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32, 33, 34 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 15C, 15D Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 15A -Subparagraph a-d Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 159 -Paragraph 17-22, 27, 28 falsefalseDisclosure of Fair Value of Financial Instruments13Disclosure of Fair Value of Financial InstrumentsUnKnownUnKnownUnKnownUnKnownfalsetrue