Disposal Group, Including Discontinued Operation, Long Lived Assets [Abstract]
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]
Related Party Transactions [Abstract]
Schedule of Equity Method Investments [Table]
Schedule of Equity Method Investments [Table]
Property, Plant and Equipment, Type [Axis]
Property, Plant and Equipment, Type [Axis]
Property, Plant and Equipment, Type [Domain]
Property, Plant and Equipment, Type [Domain]
Land, Buildings and Improvements [Member]
Land, Buildings and Improvements [Member]
Related Party Transaction [Axis]
Related Party Transaction [Axis]
Related Party Transaction [Domain]
Related Party Transaction [Domain]
Comcast Innovation and Technology Center [Member]
Comcast Innovation and Technology Center [Member]
Comcast Innovation and Technology Center is composed of two equity method investments: 1) Liberty Property 18th & Arch, LP 2) Liberty Property 18th & Arch Hotel, LLC
Liberty Venture I, LP [Member]
Liberty Venture I, LP [Member]
Liberty Venture I, LP [Member]
Related Party [Axis]
Related Party [Axis]
Related Party [Domain]
Related Party [Domain]
Equity Method Investee [Member]
Equity Method Investee [Member]
General Partner [Member]
General Partner [Member]
Schedule of Equity Method Investments [Line Items]
Schedule of Equity Method Investments [Line Items]
Comcast Innovative and Technology Center [Abstract]
Comcast Innovative and Technology Center [Abstract]
Comcast Innovative and Technology Center [Abstract]
developers fee
Revenue from Related Parties
Liberty Venture I LP [Abstract]
LIberty Venture I LP [Abstract]
LIberty Venture I LP [Abstract]
Equity Method Investment, Ownership Percentage
Equity Method Investment, Ownership Percentage
Number of real estate properties acquired
Number of real estate properties acquired
Number of real estate properties acquired
Net rentable area acquired
Net rentable area acquired
Net rentable area acquired in an asset purchase or business combination
Total purchase price
Property, Plant and Equipment, Additions
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Interest rate swaps [Text Block]
Derivative Instruments and Hedging Activities Disclosure [Text Block]
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Exercises [Table]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Legal Entity [Axis]
Legal Entity [Axis]
Entity [Domain]
Entity [Domain]
Liberty Property Limited Partnership [Member]
Liberty Property Limited Partnership [Member]
Limited Partnership.
Award Type [Axis]
Award Type [Axis]
Equity Award [Domain]
Equity Award [Domain]
Stock Option [Member]
Employee Stock Option [Member]
Class of Stock [Axis]
Class of Stock [Axis]
Class of Stock [Domain]
Class of Stock [Domain]
Common Units [Member]
Common Class B [Member]
Stock Option Exercises [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of Options Exercises in Period
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period
Segment Reporting, Measurement Disclosures [Abstract]
Segment Information
Segment Reporting Disclosure [Text Block]
Temporary Equity Disclosure [Abstract]
Temporary Equity, by Class of Stock [Table]
Temporary Equity, by Class of Stock [Table]
Temporary Equity [Line Items]
Temporary Equity [Line Items]
Stockholders' Equity Note Disclosure [Text Block]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]
Business Combination Disclosure [Text Block]
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures Disclosure [Text Block]
Equity Method Investments and Joint Ventures Disclosure [Text Block]
Statement of Financial Position [Abstract]
Statement [Table]
Statement [Table]
Series I 2 [Member]
Redeemable Preferred Stock [Member]
Statement [Line Items]
Statement [Line Items]
Amortized Cost on Deferred Financing and Leasing Costs
Amortized Cost on Deferred Financing and Leasing Costs
Amortized cost on deferred financing and leasing costs.
Noncontrolling Interest Operating Partnership Common Units Outstanding
Noncontrolling Interest, Operating Partnership, Limited Partners' Common Units Outstanding
Noncontrolling Interest of the Trust relating to the Operating Partnership. The amount of units owned by limited partners' which are outstanding.
Limited Partners' Capital Account, Units Outstanding
Limited Partners' Capital Account, Units Outstanding
Temporary Equity, Shares Outstanding
Temporary Equity, Shares Outstanding
Common Stock, Par or Stated Value Per Share
Common Stock, Par or Stated Value Per Share
Common Stock, Shares Authorized
Common Stock, Shares Authorized
Common Stock, Shares, Issued
Common Stock, Shares, Issued
Common Stock, Shares, Outstanding
Common Stock, Shares, Outstanding
Treasury Stock, Shares
Treasury Stock, Shares
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table]
Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table]
Earnings Per Share, Basic and Diluted [Line Items]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Earnings Per Share [Text Block]
Earnings Per Share [Text Block]
Stock Option Exercises [Text Block]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]
Debt Disclosure [Text Block]
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Rental Payments
Operating Leases of Lessee Disclosure [Table Text Block]
Cumulative redeemable preferred units of the Operating Partnership outstanding
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount
Units
Liquidation Preference
Temporary Equity, Redemption Price Per Share
Dividend Rate
Preferred Stock, Dividend Rate, Percentage
Statement of Cash Flows [Abstract]
OPERATING ACTIVITIES
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest
Adjustments to reconcile net income to net cash provided by operating activities:
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization
Depreciation, Depletion and Amortization
Amortization of deferred financing costs
Amortization of Financing Costs
Equity in earnings of unconsolidated joint ventures
Income (Loss) from Equity Method Investments
Distributions from unconsolidated joint ventures
Proceeds from Equity Method Investment, Dividends or Distributions
Gain on property dispositions
Gain (Loss) on Sale of Properties
Share-based compensation
Share-based Compensation
Other
Other Operating Activities, Cash Flow Statement
Changes in operating assets and liabilities:
Increase (Decrease) in Operating Capital [Abstract]
Restricted cash
Increase (Decrease) in Restricted Cash for Operating Activities
Accounts receivable
Increase (Decrease) in Accounts Receivable
Deferred rent receivable
Straight Line Rent
Prepaid expenses and other assets
Increase (Decrease) in Prepaid Expense and Other Assets
Accounts payable
Increase (Decrease) in Accounts Payable
Accrued interest
Increase (Decrease) in Interest Payable, Net
Other liabilities
Increase (Decrease) in Other Operating Liabilities
Net cash provided by operating activities
Net Cash Provided by (Used in) Operating Activities
INVESTING ACTIVITIES
Net Cash Provided by (Used in) Investing Activities [Abstract]
Investment in operating properties - acquisitions
Payments to Acquire Buildings
Investment in operating properties - other
Payments for Capital Improvements
Investments in and advances to unconsolidated joint ventures
Payments to Acquire Equity Method Investments
Distributions from unconsolidated joint ventures
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital
Net proceeds from disposition of properties/land
Proceeds from Sale of Real Estate Held-for-investment
Net proceeds from public reimbursement receivable/escrow
Proceeds from Collection of Other Receivables
Investment in development in progress
Payments to Develop Real Estate Assets
Investment in land held for development
Payments To Acquire And Develop Land
The cash outflow associated with the purchase of or development of land held for investment.
Investment in deferred leasing costs
Payments for Leasing Costs
Net cash used in investing activities
Net Cash Provided by (Used in) Investing Activities
FINANCING ACTIVITIES
Net Cash Provided by (Used in) Financing Activities [Abstract]
Net proceeds from issuance of common shares
Proceeds from Issuance of Common Stock
Redemption of preferred units
Payments for Repurchase of Redeemable Preferred Stock
Proceeds from unsecured notes
Proceeds from Issuance of Unsecured Debt
Redemption of unsecured notes
Repayments of Unsecured Debt
Proceeds from mortgage loans
Proceeds from Issuance of Secured Debt
Repayments of mortgage loans
Repayments of Secured Debt
Proceeds from credit facility
Proceeds from Long-term Lines of Credit
Repayments on credit facility
Repayments of Long-term Lines of Credit
Payment of deferred financing costs
Payments of Financing Costs
Capital contributions
Proceeds from Contributed Capital
Distributions to partners
Payments of Capital Distribution
Distribution paid on common shares
Payments of Ordinary Dividends, Common Stock
Distribution paid on units/to consolidated joint venture partners
Payments of Ordinary Dividends, Noncontrolling Interest
Net cash (used in) provided by financing activities
Net Cash Provided by (Used in) Financing Activities
Net (decrease) increase in cash and cash equivalents
Cash and Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect
Decrease in cash and cash equivalents related to foreign currency translation
Effect of Exchange Rate on Cash and Cash Equivalents
Cash and cash equivalents at beginning of period
Cash and Cash Equivalents, at Carrying Value
Cash and cash equivalents at end of period
Commitments and Contingencies
Commitments and Contingencies Disclosure [Text Block]
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosure to Statements of Cash Flows
Cash Flow, Supplemental Disclosures [Text Block]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]
Common shares [Member]
Common Class A [Member]
Schedule of Antidilutive Options Excluded from Computation of Earnings Per Share [Table]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]
Antidilutive Securities [Axis]
Antidilutive Securities [Axis]
Antidilutive Securities, Name [Domain]
Antidilutive Securities, Name [Domain]
Stock Option [Member]
Equity Option [Member]
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Options Excluded from Computation of Earnings Per Share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Foreign Currency Translation:
Cumulative Translation Adjustment Summary [Roll Forward]
Beginning balance
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax
Translation adjustment
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax
Ending balance
Net unrealized gain on derivative instruments:
Cumulative Cash Flow Hedge Adjustment Summary [Roll Forward]
Cumulative Cash Flow Hedge Adjustment Summary [Roll Forward]
Beginning balance
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax
Unrealized losses
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax
Ending balance
Total accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total
Accumulated Other Comprehensive Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total
Less: portion included in noncontrolling interest - operating partnership
Accumulated Other Comprehensive Income (Loss), Attributable to Noncontrolling Interest, Total
Accumulated Other Comprehensive Income (Loss), Attributable to Noncontrolling Interest, Total
Total accumulated other comprehensive income included in shareholders' equity
Accumulated Other Comprehensive Income (Loss), Net of Tax
Summary of Derivative Instruments [Abstract]
Summary of Derivative Instruments [Abstract]
Interest Rate Derivatives [Abstract]
Interest Rate Derivatives [Abstract]
Number of interest rate swap contracts
Number of Interest Rate Derivatives Held
aggregate notional amount
Derivative, Notional Amount
Termination value of interest rate swap, including accrued interest
Assets Needed for Immediate Settlement, Aggregate Fair Value
Interest Rate Cash Flow Hedges [Abstract]
Interest Rate Cash Flow Hedges [Abstract]
Change in fair value of swaps as a decrease to other comprehensive income
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)
Amount of loss reclassified into interest expense from AOCI
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion
Ineffective portion of the change in the fair value of swaps as an adjustment to interest expense
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness
Fair value of interest rate swaps
Interest Rate Cash Flow Hedge Liability at Fair Value
Amount estimated to be reclassified from accumulated other comprehensive income as an adjustment to interest expense
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net
Net Income (Loss) Available to Common Stockholders, Basic [Abstract]
Net Income (Loss) Available to Common Stockholders, Basic [Abstract]
Income from continuing operations net of noncontrolling interest
Income (Loss) from Continuing Operations Attributable to Parent
Discontinued operations net of noncontrolling interest
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent
Net income available to common shareholders
Net Income (Loss) Available to Common Stockholders, Basic
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Weighted Average Number of Shares Outstanding, Basic
Weighted Average Number of Shares Outstanding, Basic
Dilutive shares for long-term compensation plans
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements
Weighted Average Number of Shares Outstanding, Diluted
Weighted Average Number of Shares Outstanding, Diluted
Earnings Per Share, Basic [Abstract]
Earnings Per Share, Basic [Abstract]
Income from Continuing Operations, Per Basic Share
Income (Loss) from Continuing Operations, Per Basic Share
Income from Discontinued Operations, Per Basic Share
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share
Income per common share - basic
Earnings Per Share, Basic
Earnings Per Share, Diluted [Abstract]
Earnings Per Share, Diluted [Abstract]
Income from Continuing Operations, Per Diluted Share
Income (Loss) from Continuing Operations, Per Diluted Share
Income from Discontinued Operations, Per Diluted Share
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share
Income per common share - diluted
Earnings Per Share, Diluted
Income Statement [Abstract]
Common shares [Member]
OPERATING REVENUE
Revenues [Abstract]
Rental
Operating Leases, Income Statement, Lease Revenue
Operating expense reimbursement
Tenant Reimbursements
Total operating revenue
Real Estate Revenue, Net
OPERATING EXPENSE
Operating Expenses [Abstract]
Rental property
Direct Costs of Leased and Rented Property or Equipment
Real estate taxes
Real Estate Tax Expense
General and administrative
General and Administrative Expense
Depreciation and amortization
Depreciation, Depletion and Amortization, Nonproduction
Total operating expenses
Costs and Expenses
Operating income
Operating Income (Loss)
OTHER INCOME (EXPENSE)
Nonoperating Income (Expense) [Abstract]
Other income
Other Income
Interest expense
Interest Expense
Total other income (expense)
Nonoperating Income (Expense)
Income before (loss) gain on property dispositions, income taxes and equity in earnings of unconsolidated joint ventures
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest
(Loss) gain on property dispositions
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property
Income taxes
Income Tax Expense (Benefit)
Equity in earnings of unconsolidated joint ventures
Income from continuing operations
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest
Discontinued operations (including net gain on property dispositions of $38 and $29 for the quarters ended September 30, 2014 and 2013, respectively and $46,291 and $49,367 for the nine month periods ended September 30, 2014 and 2013, respectively)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest
Net income
Noncontrolling interest – operating partnership
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable
Noncontrolling interest - consolidated joint ventures
Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Nonredeemable
Preferred unit distributions
Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable
Excess of preferred unit redemption over carrying amount
Preferred Stock Redemption Premium
Net income available to common shareholders
Comprehensive income attributable to common shareholders
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other comprehensive (loss) income - foreign currency translation
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax
Other comprehensive income (loss) - change in net unrealized gain on derivative instruments
Other comprehensive (loss) income
Other Comprehensive Income (Loss), Net of Tax
Total comprehensive income
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest
Less: comprehensive income attributable to noncontrolling interest
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest
Comprehensive income attributable to common shareholders
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Earnings per common share
Basic:
Income from continuing operations
Income from discontinued operations
Income per common share - basic
Diluted:
Income from continuing operations
Income from discontinued operations
Income per common share - diluted
Distributions per common share or unit
Common Stock, Dividends, Per Share, Declared
Weighted average number of common shares outstanding
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Basic
Diluted
Net income allocated to general partners
Net Income (Loss) Allocated to General Partners
Net income allocated to limited partners
Net Income (Loss) Allocated to Limited Partners
Amounts attributable to common shareholders
Income Amounts Attributable to Parent, Disclosures [Abstract]
Income from continuing operations
Discontinued operations
Schedule of Long-term Debt Instruments [Table]
Schedule of Long-term Debt Instruments [Table]
Extinguishment of Debt [Axis]
Extinguishment of Debt [Axis]
Extinguishment of Debt, Type [Domain]
Extinguishment of Debt, Type [Domain]
Unsecured Notes
Unsecured Debt [Member]
Financial Covenants [Axis]
Financial Covenants [Axis]
Financial Covenants [Axis]
Financial Covenants [Domain]
Financial Covenants [Domain]
Financial Covenants [Domain]
Total Debt to Total Assets Ratio [Member]
Total Debt to Total Assets Ratio [Member]
Total Debt to Total Assets Ratio [Member]
EBITDA to Fixed Charges Ratio [Member]
EBITDA to Fixed Charges Ratio [Member]
EBITDA to Fixed Charges Ratio [Member]
Unsecured Debt to Unencumbered Asset Ratio [Member]
Unsecured Debt to Unencumbered Asset Ratio [Member]
Unsecured Debt to Unencumbered Asset Ratio [Member]
Unencumbered Net Operating Income to Unsecured Interest Expense [Member]
Unencumbered Net Operating Income to Unsecured Interest Expense [Member]
Unencumbered Net Operating Income to Unsecured Interest Expense [Member]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Domain]
Long-term Debt, Type [Domain]
Line of Credit [Member]
Line of Credit [Member]
Senior Notes [Member]
Senior Notes [Member]
Debt Instrument [Axis]
Debt Instrument [Axis]
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Old Credit Facility [Member]
Old Credit Facility [Member]
Old credit facility [Member]
New Credit Facility [Member]
New Credit Facility [Member]
New Credit Facility [Member]
5.65% Senior Note [Member]
5.65% Senior Note [Member]
5.65% Senior Note [Member]
Debt Instrument [Line Items]
Debt Instrument [Line Items]
Credit Facility [Abstract]
Line of Credit Facility [Abstract]
Line of Credit Facility, Maximum Borrowing Capacity
Line of Credit Facility, Maximum Borrowing Capacity
Length of Maturity Extension
Length of Maturity Extension
Length of Maturity Extension
Debt Instrument, Basis Spread on Variable Rate
Debt Instrument, Basis Spread on Variable Rate
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage
Line of Credit Facility, Competitive Bid Option, Percentage
Line of Credit Facility, Competitive Bid Option, Percentage
Competitive Bid Option % of Facility Amount
Borrowed Funds
Debt and Capital Lease Obligations
Assets
Assets
Line of Credit Facility, Covenant Terms, Earnings before Interest, Taxes, Depreciation and Amortization to Fixed Charges Ratio
Line of Credit Facility, Covenant Terms, Earnings before Interest, Taxes, Depreciation and Amortization to Fixed Charges Ratio
Earnings Before Interest, Taxes, Depreciation and Amortization
Line of Credit Facility, Unsecured Debt to Unencumbered Asset Value, Maximum
Line of Credit Facility, Unsecured Debt to Unencumbered Asset Value, Maximum
Unsecured Debt to Unencumbered Asset Value
Line of Credit Facility, Unencumbered Net Operating Income to Unsecured Interest Expense, Minimum
Line of Credit Facility, Unencumbered Net Operating Income to Unsecured Interest Expense, Minimum
Line of Credit Facility, Unencumbered Net Operating Income to Unsecured Interest Expense, Minimum
Debt Covenant
Unsecured Notes [Abstract]
Unsecured Debt [Abstract]
Interest Rate
Debt Instrument, Interest Rate, Stated Percentage
Repayment of unsecured note
Repayments of Senior Debt
Statement of Stockholders' Equity [Abstract]
Statement, Equity Components [Axis]
Equity Components [Axis]
Equity Component [Domain]
Equity Component [Domain]
General Partners Equity [Member]
General Partners Equity [Member]
General Partners Equity.
Common Shares Of Beneficial Interest [Member]
Common Shares Of Beneficial Interest [Member]
Common Shares Of Beneficial Interest [Member]
Additional Paid-In Capital [Member]
Additional Paid-in Capital [Member]
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Member]
Distributions in Excess of Net Income [Member]
Accumulated Distributions in Excess of Net Income [Member]
Common Shares Held in Treasury [Member]
Treasury Stock [Member]
Total Liberty Property Trust Shareholders' Equity [Member]
Parent [Member]
Noncontrolling interest operating partnership-Common [Member]
Noncontrolling interest operating partnership Common [Member]
Noncontrolling Interest Operating Partnership.
Noncontrolling interest operating partnership-Preferred [Member]
Noncontrolling interest operating partnership Preferred [Member]
NonControlling Interest Operating Partnership Preferred.
Noncontrolling interest-consolidated joint ventures [Member]
Noncontrolling interest-consolidated joint ventures [Member]
Noncontrolling Interest Consolidated Joint Ventures.
Beginning Balance
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest
Net proceeds from the issuance of common shares
Stock Issued During Period, Value, New Issues
Net income
Redemption of limited partners common units for common shares
Stock Issued During Period, Value, Conversion of Units
Contributions from partners
Partners' Capital Account, Contributions
Distributions
Dividends
Distributions to partners
Partners' Capital Account, Distributions
Share-based compensation
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition
Other comprehensive (loss) income - foreign currency translation
Redemption of noncontrolling interests - common units
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests, Common Units
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests, Common Units
Ending Balance
Supply Commitment [Table]
Supply Commitment [Table]
Range [Axis]
Range [Axis]
Range [Domain]
Range [Domain]
Maximum [Member]
Maximum [Member]
Supply Commitment [Axis]
Supply Commitment [Axis]
Supply Commitment Arrangement [Domain]
Supply Commitment Arrangement [Domain]
Construction in Progress [Member]
Construction in Progress [Member]
Development Not Yet Commenced [Member]
Development Not Yet Commenced [Member]
A planned development project that currently does not have any costs classified on the balance sheet as Development or Construction in Progress.
Buildings and land parcels [Member]
Tenant Improvements [Member]
Leasehold Improvements [Member]
Supply Commitment [Line Items]
Supply Commitment [Line Items]
Number of Real Estate Properties
Number of Real Estate Properties
Area of Real Estate Property
Area of Real Estate Property
Total anticipated development cost
Anticipated Aggregate Investment
Total anticipated cost of investment in assets including but not limited to assets under construction.
Development in Process
Development in Process
Deferred Costs, Leasing, Gross
Deferred Costs, Leasing, Gross
Remaining amount committed or obligated to pay for the benefit of current or future tenants
Supply Commitment, Remaining Minimum Amount Committed
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Consolidation Items [Axis]
Consolidation Items [Axis]
Consolidation Items [Domain]
Consolidation Items [Domain]
Intersegment Eliminations [Member]
Intersegment Eliminations [Member]
Operating Segments [Member]
Operating Segments [Member]
Discontinued Operations [Member]
Segment Reconciling Items [Member]
Corporate, Non-Segment [Member]
Corporate, Non-Segment [Member]
Segments [Axis]
Segments [Axis]
Segments [Domain]
Segments [Domain]
Carolinas [Member]
Carolinas [Member]
Carolinas Reportable Segment
Chicago Milwaukee [Member]
Chicago Milwaukee [Member]
Chicago Milwaukee Reportable Segment
Houston [Member]
Houston [Member]
Houston Reportable Segment
Lehigh Central PA [Member]
Lehigh Central PA [Member]
Lehigh Central PA [Member]
Minnesota [Member]
Minnesota [Member]
Minnesota Reportable Segment
Orlando [Member]
Orlando [Member]
Orlando reportable segment
Philadelphia [Member]
Philadelphia [Member]
Philadelphia [Member]
Richmond Hampton Roads [Member]
Richmond Hampton Roads [Member]
Richmond Hampton Roads Reportable Segment
South Florida [Member]
South Florida [Member]
South Florida Reportable Segment
Southeastern PA [Member]
Southeastern PA [Member]
Southeastern PA
Tampa [Member]
Tampa [Member]
Tampa - Reportable segment
United Kingdom [Member]
United Kingdom [Member]
United Kingdom Member.
Other Segments [Member]
Other Segments [Member]
Geographical [Axis]
Geographical [Axis]
Geographical [Domain]
Geographical [Domain]
North America [Member]
North America [Member]
European Union [Member]
European Union [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information [Line Items]
Operating revenue
Revenues
Net operating income
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization expense
(Loss) gain on property dispositions
General and administrative expense
Discontinued operations excluding gain on property dispositions
Discontinued Operations excluding Gain on Sale
Discontinued Operations excluding Gain on Sale
Other
Other Nonoperating Income (Expense)
Income from continuing operations
Gain on property dispositions
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax
Stockholders' Equity Attributable to Noncontrolling Interest [Abstract]
Noncontrolling Interests
Noncontrolling Interest Disclosure [Text Block]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table]
Long Lived Assets Held-for-sale by Asset Type [Axis]
Long Lived Assets Held-for-sale by Asset Type [Axis]
Long Lived Assets Held-for-sale, Name [Domain]
Long Lived Assets Held-for-sale, Name [Domain]
Significant Acquisitions and Disposals by Transaction [Axis]
Significant Acquisitions and Disposals by Transaction [Axis]
Significant Acquisitions and Disposals, Transaction [Domain]
Significant Acquisitions and Disposals, Transaction [Domain]
Portfolio Sale, Total [Member]
Portfolio Sale, Total [Member]
Portfolio Sale first and second settlement [Member]
Other Properties [Member]
Other Properties [Member]
Other Properties included in discontinued operations but are not a part of the Portfolio Sale[Member]
Portfolio Sale, first settlement [Member]
Portfolio Sale, first settlement [Member]
Portfolio Sale, first settlement [Member]
Portfolio Sale, Second Settlement [Member]
Portfolio Sale, Second Settlement [Member]
Portfolio Sale, Second Settlement, January 2014 [Member]
Subsegments [Axis]
Subsegments [Axis]
Subsegments [Domain]
Subsegments [Domain]
Maryland [Member]
Maryland [Member]
Maryland reportable segment. Located within the aggregated "Other" Category.
New Jersey [Member]
New Jersey [Member]
New Jersey reportable segment. Located within the "Other" category.
Disposal Group Name [Axis]
Disposal Group Name [Axis]
Disposal Groups, Including Discontinued Operations, Name [Domain]
Disposal Groups, Including Discontinued Operations, Name [Domain]
Discontinued Operations [Member]
Discontinued Operations [Member]
Not Discontinued Operations [Member]
Not Discontinued Operations [Member]
Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Significant Disposals, Sale Proceeds
Significant Acquisitions and Disposals, Acquisition Costs or Sale Proceeds
Number of Real Estate Settlements
Number of Real Estate Settlements
Number of Real Estate Settlements
Acres of land sold
Area of Land
Number of Real Estate Properties Sold
Number of Real Estate Properties Sold
Number of Real Estate Properties Sold
Proceeds from Sale of Property
Proceeds from Sale of Property, Plant, and Equipment
Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract]
Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract]
Revenues
Disposal Group, Including Discontinued Operation, Revenue
Operating expenses
Disposal Group, Including Discontinued Operation, Operating Expense
Interest and other income
Disposal Group, Including Discontinued Operation, Other Income
Interest expense
Disposal Group, Including Discontinued Operation, Interest Expense
Depreciation and Amortization
Disposal Group, Including Discontinued Operation, Depreciation and Amortization
Income before (loss) gain on property dispositions
Disposal Group, Including Discontinued Operation, Operating Income (Loss)
(Loss) gain on property dispositions
Income from discontinued operations
Noncontrolling Interest
Disposal Group, Noncontrolling Interest In Net Income Loss Operating Partnerships Redeemable
Disposal Group, Noncontrolling Interest In Net Income Loss Operating Partnerships Redeemable
Income from discontinued operations available to common shareholders
Disposal Group, Net Income (Loss) Available to Common Stockholders, Basic
Disposal Group, Net Income (Loss) Available to Common Stockholders, Basic
Discontinued Operation, Additional Disclosures [Abstract]
Discontinued Operation, Additional Disclosures [Abstract]
Disposal Group, Including Discontinued Operation, Operating Cash Flows
Net Cash Provided by (Used in) Disposal Group, Including Discontinued Operation, Operating Cash Flows
Net Cash Provided by (Used in) Disposal Group, Including Discontinued Operation, Operating Cash Flows
Disposal Group, Including Discontinued Operations, Investing Cash Flows
Net Cash Provided by (Used in) Disposal Group, Including Discontinued Operations, Investing Cash Flows
Net Cash Provided by (Used in) Disposal Group, Including Discontinued Operations, Investing Cash Flows
Redeemable Noncontrolling Interest, by Legal Entity [Table]
Redeemable Noncontrolling Interest, by Legal Entity [Table]
Reportable Legal Entities [Member]
Reportable Legal Entities [Member]
Redeemable Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interest [Line Items]
Common units, units outstanding not held by the trust
Market value of common units based on closing price
Redeemable Noncontrolling Interest, Equity, Common, Fair Value
Significant Transaction Name [Axis]
Significant Transaction Name [Axis]
Significant Transaction Name [Axis]
Significant Transaction Name [Domain]
Significant Transaction Name [Domain]
[Domain] for Significant Transaction Name [Axis]
Comcast corporation lease [Member]
Comcast corporation lease [Member]
Comcast corporation lease [Member]
Significant Transaction Type [Axis]
Significant Transaction Type [Axis]
The types of significant transactions a company enters into that are material enough to disclose in the notes to the financial statements.
Significant Transaction Type [Domain]
Significant Transaction Type [Domain]
[Domain] for The types of significant transactions a company enters into that are material enough to disclose in the notes to the financial statements.
Lease Agreements [Member]
Lease Agreements [Member]
Investment, Name [Axis]
Investment, Name [Axis]
Investment, Name [Domain]
Investment, Name [Domain]
Number of equity method investments
Number of equity method investments
Number of equity method investments
Number of stories in a high-rise building
Number of stories in a high-rise building
Number of stories in a high-rise building
Net Rentable Area
Net Rentable Area
Number of hotel rooms
Number of hotel rooms
Number of hotel rooms in a hotel
Anticipated investment in joint ventures
Anticipated investment in joint ventures
Anticipated balance in investment in unconsolidated joint ventures after development is completed.
Real Estate Investments, Joint Ventures
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
Length of Lease
Lessor Leasing Arrangements, Operating Leases, Term of Contract
Percent of net rentable area
Percent of net rentable area
Percent of net rentable area
Supplemental Disclosure to Statements of Cash Flows
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]
Schedule of Temporary Equity [Table Text Block]
Temporary Equity [Table Text Block]
Debt Instrument, Fair Value Disclosure [Abstract]
Disclosure of Fair Value of Financial Instruments
Fair Value Disclosures [Text Block]
Document and Entity Information [Abstract]
Document And Entity Information.
Entities [Table]
Entities [Table]
Entity Information [Line Items]
Entity Information [Line Items]
Entity Registrant Name
Entity Registrant Name
Entity Central Index Key
Entity Central Index Key
Current Fiscal Year End Date
Current Fiscal Year End Date
Entity Filer Category
Entity Filer Category
Document Type
Document Type
Document Period End Date
Document Period End Date
Document Fiscal Year Focus
Document Fiscal Year Focus
Document Fiscal Period Focus
Document Fiscal Period Focus
Amendment Flag
Amendment Flag
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
Accumulated Other Comprehensive Income (Loss) Note [Text Block]
Comprehensive Income (Loss) Note [Text Block]
Long-term Purchase Commitment [Table]
Long-term Purchase Commitment [Table]
Category of Item Purchased [Axis]
Category of Item Purchased [Axis]
Long-term Purchase Commitment, Category of Item Purchased [Domain]
Long-term Purchase Commitment, Category of Item Purchased [Domain]
Land Purchases [Member]
Capital Addition Purchase Commitments [Member]
Long-term Purchase Commitment [Line Items]
Long-term Purchase Commitment [Line Items]
Remaining amount commitment to future land purchases
Purchase Commitment, Remaining Minimum Amount Committed
2014
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year
2015
Operating Leases, Future Minimum Payments, Due in Two Years
2016
Operating Leases, Future Minimum Payments, Due in Three Years
2017
Operating Leases, Future Minimum Payments, Due in Four Years
2018
Operating Leases, Future Minimum Payments, Due in Five Years
2019 through 2034
Operating Leases, Future Minimum Payments, Due Thereafter
Total
Operating Leases, Future Minimum Payments Due
Other Expenses [Abstract]
Other Expenses [Abstract]
Operating ground lease expense
Operating Ground Lease Expense
Operating Ground Lease Expense
ASSETS
Assets [Abstract]
Land and land improvements
Land and Land Improvements
Building and improvements
Investment Building and Building Improvements
Less accumulated depreciation
Real Estate Investment Property, Accumulated Depreciation
Operating real estate
Operating real estate
Sum of the carrying amounts as of the balance sheet date of all operating real estate assets.
Development in progress
Land held for development
Land Available for Development
Net real estate
Real Estate Investment Property, Net
Cash and cash equivalents
Restricted cash
Restricted Cash and Cash Equivalents
Accounts receivable
Accounts Receivable, Net
Deferred rent receivable
Deferred Rent Receivables, Net
Deferred financing and leasing costs, net of accumulated amortization (2014, $167,045; 2013, $140,933)
Deferred costs, net
Deferred costs, including deferred leasing and financing costs and intangible assets including to intangible market rent and intangible leases net of accumulated amortization.
Investments in and advances to unconsolidated joint ventures
Assets held for sale
Disposal Group, Including Discontinued Operation, Assets
Prepaid expenses and other assets
Prepaid Expense and Other Assets
Total assets
LIABILITIES
Liabilities [Abstract]
Mortgage loans
Secured Debt
Unsecured notes
Unsecured Debt
Credit facility
Long-term Line of Credit
Accounts payable
Accounts Payable
Accrued interest
Interest Payable
Dividend and distributions payable
Dividends Payable
Other liabilities
Other Liabilities
Total liabilities
Liabilities
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2014 and December 31, 2013
EQUITY
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Common shares of beneficial interest, $.001 par value, 283,987,000 shares authorized; 149,354,294 (includes 1,249,909 in treasury) and 147,846,801 (includes 1,249,909 in treasury) shares issued and outstanding as of September 30, 2014 and December 31, 2013, respectively
Common Stock, Value, Issued
General partner’s equity - 148,104,385 (net of 1,249,909 treasury units) and 146,596,892 (net of 1,249,909 treasury units) common units outstanding as of September 30, 2014 and December 31, 2013, respectively
General Partners' Capital Account
Limited partners' equity
Limited Partners' Capital Account
Additional paid-in capital
Additional Paid in Capital
Accumulated other comprehensive loss
Distributions in excess of net income
Accumulated Distributions in Excess of Net Income
Common shares in treasury, at cost, 1,249,909 shares as of September 30, 2014 and December 31, 2013
Treasury Stock, Value
Total Liberty Property Trust shareholders' equity
Stockholders' Equity Attributable to Parent
Noncontrolling interest - operating partnership
Noncontrolling interest - operating partnerships
Noncontrolling Interest in Operating Partnerships
Noncontrolling interest - consolidated joint ventures
Noncontrolling Interest in Joint Ventures
Total equity
Total liabilities, noncontrolling interest - operating partnership and equity
Liabilities and Equity
Limited Partners' Equity of the Operating Partnership [Abstract]
Limited Partners' Equity of the Operating Partnership [Abstract]
Schedule of Limited Partners' Capital Account by Class [Table]
Schedule of Limited Partners' Capital Account by Class [Table]
Limited Partners' Capital Account [Line Items]
Limited Partners' Capital Account [Line Items]
market value of the outstanding common units
market value of the outstanding common units
Market value of the limited partners' outstanding common units as of period end based on the closing price of the common shares of the trust.
Fair Value, by Balance Sheet Grouping [Table]
Fair Value, by Balance Sheet Grouping [Table]
Measurement Basis [Axis]
Measurement Basis [Axis]
Fair Value Measurement [Domain]
Fair Value Measurement [Domain]
Carrying Value
Portion at Other than Fair Value Measurement [Member]
Fair Value
Estimate of Fair Value Measurement [Member]
Fair Value, Hierarchy [Axis]
Fair Value, Hierarchy [Axis]
Fair Value Hierarchy [Domain]
Fair Value Hierarchy [Domain]
Fair Value, Inputs, Level 3 [Member]
Fair Value, Inputs, Level 3 [Member]
Fair Value by Liability Class [Axis]
Liability Class [Axis]
Fair Value, Liabilities, Measured on Recurring Basis, Unobservable Input Reconciliation, by Liability Class [Domain]
Fair Value by Liability Class [Domain]
Mortgage Loans
Mortgage Loans on Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value
Long-term Debt, Fair Value
Fair Value, by Balance Sheet Grouping [Table Text Block]
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment [Table]
Property, Plant and Equipment [Table]
Land [Member]
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment [Line Items]
Acquisitions [Abstract]
Acquisitions [Abstract]
Any type of acquisition by the entity.
Dispositions [Abstract]
Dispositions [Abstract]
Any type of disposition by the entity, including dispositions both classified as discontinued operations and not discontinued operations.
Schedule of Business Acquisitions, by Acquisition [Table]
Schedule of Business Acquisitions, by Acquisition [Table]
Mortgages [Member]
Mortgages [Member]
Real Estate, Type of Property [Axis]
Real Estate, Type of Property [Axis]
Real Estate [Domain]
Real Estate [Domain]
Industrial Property [Member]
Industrial Property [Member]
Business Acquisition [Axis]
Business Acquisition [Axis]
Business Acquisition, Acquiree [Domain]
Business Acquisition, Acquiree [Domain]
Cabot Industrial Value Fund III [Member]
Cabot Industrial Value Fund III [Member]
Cabot Industrial Value Fund III [Member]
Business Acquisition [Line Items]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition
Business Acquisition, Effective Date of Acquisition
Business Acquisition, Name of Acquired Entity
Business Acquisition, Name of Acquired Entity
Business Acquisition, Percentage of Voting Interests Acquired
Business Acquisition, Percentage of Voting Interests Acquired
Business Combination, Consideration Transferred
Business Combination, Consideration Transferred
Business Combination, Consideration Transferred, Liabilities Incurred
Business Combination, Consideration Transferred, Liabilities Incurred
Schedule of Segment Reporting Information, by Segment, Revenue and Net Operating Income [Table Text Block]
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Reconciliation of Assets from Segment to Consolidated [Table Text Block]
Reconciliation of Assets from Segment to Consolidated [Table Text Block]
Less: Preferred unit distributions
Preferred Stock Dividends, Income Statement Impact
Income from Continuing Operations available to Common Unitholders
Income from Continuing Operations available to Common Unitholders
Income from Continuing Operations available to Common Unitholders
Discontinued operations
Dilutive units for long-term compensation plans
Weighted Average Number of Shares Outstanding, Diluted
New Accounting Pronouncements, Policy [Policy Text Block]
New Accounting Pronouncements, Policy [Policy Text Block]
Schedule of Preferred Units [Table]
Preferred Units [Line Items]
Noncontrolling Interest Disclosure [Text Block]
Write off of fully depreciated property and deferred costs
Write off of fully depreciated property and deferred costs
Write off of fully depreciated property and deferred costs
Write off of depreciated property and deferred costs due to sale
Write Off Of Depreciated Property And Deferred Costs Due To Sale
Write Off Of Depreciated Property And Deferred Costs Due To Sale
Unrealized losses on cash flow hedge, non cash transaction
Unrealized gain (loss) on cash flow hedge, non cash transaction
Unrealized gain (loss) on cash flow hedge, non cash transaction
Write-off of preferred units costs due to redemption
Write-off of preferred units costs due to redemption
Write-off of preferred units costs due to redemption, noncash transaction
Increase in investments in and advances to unconsolidated joint ventures due to disposition activity
Non cash change in investment in unconsolidated joint ventures
Non cash change in investment in unconsolidated joint ventures
Changes in accrued development capital expenditures
Construction in Progress Expenditures Incurred but Not yet Paid
Legal Matters [Abstract]
Loss Contingency, Quantities [Abstract]
Loss Contingency, Pending Claims, Number
Loss Contingency, Pending Claims, Number
Other [Abstract]
Other Liabilities, Unclassified [Abstract]
Letter of credit obligations
Letters of Credit Outstanding, Amount
Assets
Ownership interest in operating partnership - Limited Partnership
Noncontrolling Interest, Ownership Percentage by Parent