Statement of Cash Flows [Abstract]
Statement [Table]
Statement [Table]
Legal Entity [Axis]
Legal Entity [Axis]
Entity [Domain]
Entity [Domain]
Liberty Property Limited Partnership [Member]
Liberty Property Limited Partnership [Member]
Limited Partnership.
Statement [Line Items]
Statement [Line Items]
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 Debt Issuance 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/Non-cash 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 properties - acquisitions
Payments to Acquire Buildings
Investment in 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
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.
Payment of deferred leasing costs
Payments for Leasing Costs
Investing - Other
Payments for (Proceeds from) Other Investing Activities
Net cash (used in) provided by 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
Share repurchase including shares related to tax withholdings
Payments for Repurchase of Common Stock
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
Distribution paid on common shares
Payments of Ordinary Dividends, Common Stock
Distribution paid on units
Payments of Ordinary Dividends, Noncontrolling Interest
Capital contributions
Proceeds from Contributed Capital
Distributions to partners/noncontrolling interests
Payments of Capital Distribution
Net cash provided by (used in) 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
Increase (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
Supplemental Cash Flow Information [Abstract]
Write-off of fully depreciated/amortized 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/amortized property and deferred costs due to sale/demolition
Write Off Of Depreciated Property And Deferred Costs Due To Sale
Write Off Of Depreciated Property And Deferred Costs Due To Sale
Redemption of noncontrolling interests - common units
Conversion of Stock, Amount Converted
Unrealized gain (loss) on cash flow hedge
Unrealized gain (loss) on cash flow hedge, non cash transaction
Unrealized gain (loss) on cash flow hedge, non cash transaction
Changes in accrued development capital expenditures
Increase (Decrease) in Accrued Liabilities
Capitalized equity-based compensation
Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount
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]
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
Temporary Equity Disclosure [Abstract]
Temporary Equity, by Class of Stock [Table]
Temporary Equity, by Class of Stock [Table]
Series I 2 [Member]
Redeemable Preferred Stock [Member]
Temporary Equity [Line Items]
Temporary Equity [Line Items]
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of March 31, 2017 and December 31, 2016
Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests
Units
Temporary Equity, Shares Outstanding
Liquidation Preference
Temporary Equity, Redemption Price Per Share
Dividend Rate
Preferred Stock, Dividend Rate, Percentage
Stockholders' Equity Attributable to Noncontrolling Interest [Abstract]
Noncontrolling Interests
Noncontrolling Interest Disclosure [Text Block]
Indebtedness [Abstract]
Indebtedness [Abstract]
Schedule of Temporary Equity [Table Text Block]
Temporary Equity [Table Text Block]
Limited Partners' Equity of the Operating Partnership [Abstract]
Limited Partners' Equity of the Operating Partnership [Abstract]
Schedule of Preferred Units [Table]
Preferred Units [Line Items]
Noncontrolling Interest Disclosure [Text Block]
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments, Gain (Loss) [Table Text Block]
Derivative Instruments, Gain (Loss) [Table Text Block]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Asset Impairment Charges [Text Block]
Asset Impairment Charges [Text Block]
Basis of Presentation [Abstract]
Basis of Presentation [Abstract]
Prior Period Adjustment [Table]
Schedule of Error Corrections and Prior Period Adjustment Restatement [Table]
Adjustments for New Accounting Pronouncements [Axis]
Adjustments for New Accounting Pronouncements [Axis]
Type of Adoption [Domain]
Type of Adoption [Domain]
Accounting Standards Update 2016-09 [Member]
Accounting Standards Update 2016-09 [Member]
Accounting Standards Update 2016-09 Improvements to Employee Share-Based Payment Accounting
Income Statement Location [Axis]
Income Statement Location [Axis]
Income Statement Location [Domain]
Income Statement Location [Domain]
Other Income [Member]
Other Income [Member]
General and Administrative Expense [Member]
General and Administrative Expense [Member]
Scenario [Axis]
Scenario [Axis]
Scenario, Unspecified [Domain]
Scenario, Unspecified [Domain]
Scenario, Previously Reported [Member]
Scenario, Previously Reported [Member]
Prior Period Adjustments [Line Items]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash outflow for shares related to tax withholdings
Development service fee income
Property Management Fee Revenue
Development service fee expense
Construction and Development Costs
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
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment [Table]
Property, Plant and Equipment [Table]
Segments [Axis]
Segments [Axis]
Segments [Domain]
Segments [Domain]
Property, Plant and Equipment, Type [Axis]
Property, Plant and Equipment, Type [Axis]
Property, Plant and Equipment, Type [Domain]
Property, Plant and Equipment, Type [Domain]
Range [Axis]
Range [Axis]
Range [Domain]
Range [Domain]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment [Line Items]
Impairment - real estate assets
Impairment of Real Estate
Commitments and Contingencies Disclosure [Abstract]
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
Contractual Obligation
Contractual Obligation
Income Statement [Abstract]
Common shares [Member]
Common Class A [Member]
OPERATING REVENUE
Revenues [Abstract]
Rental
Operating Leases, Income Statement, Lease Revenue
Operating expense reimbursement
Tenant Reimbursements
Development service fee income
Fees and Commissions, Other
Total operating revenue
Revenues
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]
Interest and other income
Other Income
Interest expense
Interest Expense
Total other income (expense)
Nonoperating Income (Expense)
Income before 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, Noncontrolling Interest
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, 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
Preferred Stock Dividends, Income Statement Impact
Net income available to common shareholders
Net Income (Loss) Available to Common Stockholders, Basic
Comprehensive income attributable to common shareholders
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other comprehensive gain (loss) - foreign currency translation
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax
Other comprehensive gain (loss) - derivative instruments
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax
Other comprehensive income (loss)
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
Earnings Per Share [Abstract]
Basic:
Earnings Per Share, Basic [Abstract]
Income per common share - basic
Earnings Per Share, Basic
Diluted:
Earnings Per Share, Diluted [Abstract]
Income per common share - diluted
Earnings Per 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
Weighted Average Number of Shares Outstanding, Basic
Diluted
Weighted Average Number of Shares Outstanding, 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
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent
Net income available to common shareholders
Supplemental Disclosure to Statements of Cash Flows
Cash Flow, Supplemental Disclosures [Text Block]
Schedule of Adjustments to Previously Reported Financial Statements
Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]
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]
Limited Partners' common units outstanding
Limited Partners' Capital Account, Units Outstanding
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.
Long-term Purchase Commitment [Table]
Long-term Purchase Commitment [Table]
Land and Land Improvements [Member]
Land and Land Improvements [Member]
Land, Buildings and Improvements [Member]
Land, Buildings and Improvements [Member]
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 committed to future acquisitions
Purchase Commitment, Remaining Minimum Amount Committed
Redeemable Noncontrolling Interest, by Legal Entity [Table]
Redeemable Noncontrolling Interest, by Legal Entity [Table]
Consolidation Items [Axis]
Consolidation Items [Axis]
Consolidation Items [Domain]
Consolidation Items [Domain]
Redeemable Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interest [Line Items]
Market value of common units based on closing price
Redeemable Noncontrolling Interest, Equity, Common, Fair Value
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Intersegment Eliminations [Member]
Intersegment Eliminations [Member]
Operating Segments [Member]
Operating Segments [Member]
Corporate, Non-Segment [Member]
Corporate, Non-Segment [Member]
Carolinas Richmond [Member]
Carolinas Richmond [Member]
Carolinas Richmond [Member]
Chicago Minneapolis [Member]
Chicago Minneapolis [Member]
The Company's reportable segment of Chicago/Minneapolis.
Florida [Member]
Florida [Member]
Area in the state of Florida which formally included the segments Tampa, Orlando and South Florida.
Houston [Member]
Houston [Member]
Houston Reportable Segment
Lehigh Central PA [Member]
Lehigh Central PA [Member]
Lehigh Central PA [Member]
Philadelphia [Member]
Philadelphia [Member]
Philadelphia [Member]
Southeastern PA [Member]
Southeastern PA [Member]
Southeastern PA
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]
UNITED KINGDOM
UNITED KINGDOM
Segment Reporting Information [Line Items]
Segment Reporting Information [Line Items]
Operating revenue
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
Gain on property dispositions
General and administrative expense
Other
Other Nonoperating Income (Expense)
Net income
Earnings Per Share [Text Block]
Earnings Per Share [Text Block]
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]
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
Equity [Abstract]
Schedule of Stock by Class [Table]
Schedule of Stock by Class [Table]
Share Repurchase Program [Axis]
Share Repurchase Program [Axis]
Share Repurchase Program [Domain]
Share Repurchase Program [Domain]
2015 Share Repurchase Program [Member]
2015 Share Repurchase Program [Member]
Share repurchase program authorized by the Board of Trustees in 2015.
Class of Stock [Line Items]
Class of Stock [Line Items]
Authorized amount of shares available to be repurchased under a share repurchase plan
Stock Repurchase Program, Authorized Amount
Number of shares repurchased during period
Stock Repurchased During Period, Shares
Real Estate [Abstract]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]
Schedule of Earnings Per Share, Basic and Diluted [Table]
Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table]
Common shares [Member]
Earnings Per Share, Basic and Diluted [Line Items]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Income (Numerator) [Abstract]
Net Income (Loss) Available to Common Stockholders, Basic [Abstract]
Weighted Average Shares (Denominator) [Abstract]
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
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
Earnings Per Unit, Basic and Diluted [Line Items]
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]
Assets by Segment [Abstract]
Assets by Segment [Abstract]
Assets
Assets
Interest rate swaps [Text Block]
Derivative Instruments and Hedging Activities Disclosure [Text Block]
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]
Schedule of Equity Method Investments [Table]
Schedule of Equity Method Investments [Table]
Disposal Group Name [Axis]
Disposal Group Name [Axis]
Disposal Group Name [Domain]
Disposal Group Name [Domain]
Joint venture, 2017 sales current quarter [Member]
Joint venture, 2017 sales current quarter [Member]
Any sales by the Company's unconsolidated joint ventures during the current quarter of the fiscal year 2017.
Joint venture, 2016 sales current quarter [Member]
Joint venture, 2016 sales current quarter [Member]
Joint venture, 2016 sales during the current quarter
Gain on equity method investments [Member]
Gain (Loss) on Investments [Member]
Investment, Name [Axis]
Investment, Name [Axis]
Investment, Name [Domain]
Investment, Name [Domain]
Cambridge Medipark Ltd [Member]
Cambridge Medipark Ltd [Member]
Cambridge Medipark Ltd [Member]
Disposal Group Classification [Axis]
Disposal Group Classification [Axis]
Disposal Group Classification [Domain]
Disposal Group Classification [Domain]
Disposal Group, Not Discontinued Operations [Member]
Disposal Group, Not Discontinued Operations [Member]
Leaseholds and Leasehold Improvements [Member]
Leaseholds and Leasehold Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage
Equity Method Investment, Ownership Percentage
Gain (loss) on sale of leasehold interests
Gain (Loss) on Sale of Investments
Statement of Financial Position [Abstract]
Deferred financing and leasing costs, accumulated amortization
Deferred Costs, Leasing, Accumulated Amortization
Noncontrolling interest - operating partnership, preferred units outstanding
Common shares of beneficial interest, par value per share
Common Stock, Par or Stated Value Per Share
Common shares of beneficial interest, shares authorized
Common Stock, Shares Authorized
Common shares of beneficial interest, shares issued
Common Stock, Shares, Issued
Common shares of beneficial interest, shares outstanding
Common Stock, Shares, Outstanding
ASSETS
Assets [Abstract]
Real Estate [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
Real Estate Investments, Other
Development in progress
Development in Process
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 (March 31, 2017, $156,509; December 31, 2016, $152,309)
Deferred Costs, Leasing, Net
Investments in and advances to unconsolidated joint ventures
Investments in and Advance to Affiliates, Subsidiaries, Associates, and 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
EQUITY
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Common shares of beneficial interest, $.001 par value, 283,987,000 shares authorized; 147,203,022 and 146,993,018 shares issued and outstanding as of March 31, 2017 and December 31, 2016, respectively
Common Stock, Value, Issued
General partner’s equity - 147,203,022 and 146,993,018 common units outstanding as of March 31, 2017 and December 31, 2016, respectively
General Partners' Capital Account
Limited partners' equity
Limited Partners' Capital Account
Additional paid-in capital
Additional Paid in Capital
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss), Net of Tax
Distributions in excess of net income
Accumulated Distributions in Excess of Net Income
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 owners' equity
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest
Total liabilities, noncontrolling interest - operating partnership and equity
Liabilities and Equity
2017 (remaining)
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year
2018
Operating Leases, Future Minimum Payments, Due in Two Years
2019
Operating Leases, Future Minimum Payments, Due in Three Years
2020
Operating Leases, Future Minimum Payments, Due in Four Years
2021
Operating Leases, Future Minimum Payments, Due in Five Years
2022 and thereafter
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
Debt Instrument, Fair Value Disclosure [Abstract]
Fair Value, by Balance Sheet Grouping [Table]
Fair Value, by Balance Sheet Grouping [Table]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Domain]
Long-term Debt, Type [Domain]
Unsecured Debt [Member]
Unsecured Debt [Member]
Mortgages [Member]
Mortgages [Member]
Measurement Basis [Axis]
Measurement Basis [Axis]
Fair Value Measurement [Domain]
Fair Value Measurement [Domain]
Portion at Fair Value Measurement [Member]
Portion at 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]
Long-term Debt [Member]
Long-term Debt [Member]
Mortgage Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt
Financial and Nonfinancial Liabilities, Fair Value Disclosure
Unsecured Debt
Fair Value, by Balance Sheet Grouping [Table Text Block]
Commitments and Contingencies
Commitments and Contingencies Disclosure [Text Block]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]
New Accounting Pronouncements, Policy [Policy Text Block]
Segment Reporting, Measurement Disclosures [Abstract]
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]
Assets by Segment and Reconciliation to Consolidated[Table Text Block]
Reconciliation of Assets from Segment to Consolidated [Table Text Block]
Supplemental Disclosure to Statements of Cash Flows
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]
Accumulated Other Comprehensive Income (Loss) Note [Text Block]
Comprehensive Income (Loss) Note [Text Block]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]
Supply Commitment [Table]
Supply Commitment [Table]
American Water Works, Inc [Member]
American Water Works, Inc [Member]
American Water Works, Inc [Member]
Related Party [Axis]
Related Party [Axis]
Related Party [Domain]
Related Party [Domain]
Equity Method Investments [Member]
Equity Method Investments [Member]
Supply Commitment [Axis]
Supply Commitment [Axis]
Supply Commitment Arrangement [Domain]
Supply Commitment Arrangement [Domain]
Construction in Progress [Member]
Construction in Progress [Member]
Buildings and land parcels [Member]
Tenant Improvements [Member]
Leasehold Improvements [Member]
Building and Building Improvements [Member]
Building and Building Improvements [Member]
Supply Commitment [Line Items]
Supply Commitment [Line Items]
Net Rentable Area
Net Rentable Area
Number of Real Estate Properties
Number of Real Estate Properties
Total anticipated development cost
Anticipated Aggregate Investment
Total anticipated cost of investment in assets including but not limited to assets under construction.
Development in progress
Deferred leasing costs in development
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
Tenant improvements not yet completed
Supply Commitment, Remaining Maximum Amount Committed
Supply Commitment, Remaining Maximum Amount Committed
Development for fee revenue
Other Commitment
Cost of Real Estate Sales
Cost of Real Estate Sales
Schedule of Variable Interest Entities [Table]
Schedule of Variable Interest Entities [Table]
Liberty Comcast 1701 JFK Boulevard, LP [Member]
Liberty Comcast 1701 JFK Boulevard, LP [Member]
Liberty Comcast 1701 JFK Boulevard, LP formerly known as Liberty Commerz 1701 JFK Boulevard, LP [Member]
Variable Interest Entities [Axis]
Variable Interest Entities [Axis]
Variable Interest Entity, Classification [Domain]
Variable Interest Entity, Classification [Domain]
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity, Not Primary Beneficiary [Member]
Balance Sheet Location [Axis]
Balance Sheet Location [Axis]
Balance Sheet Location [Domain]
Balance Sheet Location [Domain]
Other Investments [Member]
Other Investments [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity [Line Items]
Equity investment in joint venture
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net
Ownership interest in operating partnership - Limited Partnership
Noncontrolling Interest, Ownership Percentage by Parent
Maximum exposure to loss
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount
Authorized amount of shares available to be repurchased under a share repurchase plan
Number of units repurchased during period
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Schedule of Long-term Debt Instruments [Table]
Schedule of Long-term Debt Instruments [Table]
Debt Instrument [Axis]
Debt Instrument [Axis]
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Debt Instrument [Line Items]
Debt Instrument [Line Items]
Segment Information
Segment Reporting Disclosure [Text Block]
Future Minimum Rental Payments
Operating Leases of Lessee Disclosure [Table Text Block]
Assets Held for Sale [Abstract]
Assets Held for Sale [Abstract]
Disposal Groups, Including Discontinued Operations [Table]
Disposal Groups, Including Discontinued Operations [Table]
2017 held for sale [Member]
2017 held for sale [Member]
Land held for development that was held for sale during 2017 as of the balance sheet date[Member]
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Disposal Group, Held-for-sale, 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]
Area of Land
Area of Land
Land held for development
Disposal Group, Including Discontinued Operation, Land Available for Development
Land available for development that is included in a disposal group or assets held for sale.
Accumulated Other Comprehensive Income (Loss) [Table]
Accumulated Other Comprehensive Income (Loss) [Table]
Equity Components [Axis]
Equity Components [Axis]
Equity Component [Domain]
Equity Component [Domain]
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Attributable to Noncontrolling Interest [Member]
AOCI Attributable to Noncontrolling Interest [Member]
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance
Unrealized loss
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax
Reclassification adjustment
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax
Ending Balance
Total accumulated other comprehensive loss
Total accumulated other comprehensive loss included in shareholders' equity/owners' equity
Disclosure of Fair Value of Financial Instruments
Fair Value Disclosures [Text Block]
Stockholders' Equity Note Disclosure [Text Block]
Statement of Stockholders' Equity [Abstract]
Equity Components [Axis]
Common Stock [Member]
Common Stock [Member]
Additional Paid-in Capital [Member]
Additional Paid-in Capital [Member]
AOCI Attributable to Parent [Member]
Accumulated Distributions in Excess of Net Income [Member]
Accumulated Distributions in Excess of Net Income [Member]
Parent [Member]
Parent [Member]
Noncontrolling interest operating partnership Common [Member]
Noncontrolling interest operating partnership Common [Member]
Noncontrolling Interest Operating Partnership.
Noncontrolling interest-consolidated joint ventures [Member]
Noncontrolling interest-consolidated joint ventures [Member]
Noncontrolling Interest Consolidated Joint Ventures.
Partner Type [Axis]
Partner Type [Axis]
Partner Type of Partners' Capital Account, Name [Domain]
Partner Type of Partners' Capital Account, Name [Domain]
General Partner [Member]
General Partner [Member]
Limited Partner [Member]
Limited Partner [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from the issuance of common shares
Stock Issued During Period, Value, New Issues
Net income
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest
Contributions from partners
Partners' Capital Account, Contributions
Distributions
Dividends, Common Stock
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 income - foreign currency translation
Other comprehensive income - derivative instruments
Redemption of noncontrolling interests - common units
Stock Issued During Period, Value, Conversion of Units
Increase (Decrease) in Temporary Equity [Roll Forward]
Increase (Decrease) in Temporary Equity [Roll Forward]
Noncontrolling Interest - Operating Partnership (Mezzanine) - Beginning Balance
Net income (Mezzanine)
Temporary Equity, Net Income
Distributions (Mezzanine)
Temporary Equity, Other Changes
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance
Derivative Instruments, Gain (Loss) [Table]
Derivative Instruments, Gain (Loss) [Table]
Derivative Instrument [Axis]
Derivative Instrument [Axis]
Derivative Contract [Domain]
Derivative Contract [Domain]
Interest Rate Swap [Member]
Interest Rate Swap [Member]
Interest Expense [Member]
Interest Expense [Member]
Other Comprehensive Income Location [Axis]
Other Comprehensive Income Location [Axis]
Other Comprehensive Income Location [Domain]
Other Comprehensive Income Location [Domain]
Other Comprehensive Income (Loss) [Member]
Other Comprehensive Income (Loss) [Member]
Hedging Designation [Axis]
Hedging Designation [Axis]
Hedging Designation [Domain]
Hedging Designation [Domain]
Designated as Hedging Instrument [Member]
Designated as Hedging Instrument [Member]
Hedging Relationship [Axis]
Hedging Relationship [Axis]
Hedging Relationship [Domain]
Hedging Relationship [Domain]
Cash Flow Hedging [Member]
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) related to the effective portion recognized in other comprehensive loss
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net
Amount of loss related to the effective portion subsequently reclassified to interest expense
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion
Amount of gain (loss) related to the ineffective portion recognized in interest expense
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness
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]
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 increase to interest expense
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net
Income from continuing operations net of noncontrolling interest - consolidated joint ventures
Less: Preferred unit distributions
Weighted Average Units (Denominator) [Abstract]
Dilutive units for long-term compensation plans
Weighted Average Number of Shares Outstanding, Diluted
Earnings Per Unit, Basic [Abstract]
Earnings Per Unit, Diluted [Abstract]
Business Combination, Separately Recognized Transactions [Axis]
Business Combination, Separately Recognized Transactions [Axis]
Business Combination, Separately Recognized Transactions [Domain]
Business Combination, Separately Recognized Transactions [Domain]
2017 sales [Member]
2017 sales [Member]
All real estate assets sold during the year ended December 31, 2017.
Proceeds from Sale of Buildings and Land