Debt Instrument, Fair Value Disclosure [Abstract] Fair Value, by Balance Sheet Grouping [Table 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] 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 shares [Member] Common Class A [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 Organization, Consolidation and Presentation of Financial Statements [Abstract] Loss Contingency Accrual Loss Contingency Accrual Profit (loss) on development fee contracts Gain (loss) on development fee contracts The net profit or loss from development service fee contracts. Income statement line items Development Service Fee Income and Development Service Fee Expense. 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] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Liberty Property Limited Partnership [Member] Liberty Property Limited Partnership [Member] Limited Partnership. Earnings Per Unit, 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] Segment Reporting [Abstract] Segment Information Segment Reporting Disclosure [Text Block] Income Statement [Abstract] Statement [Table] Statement [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Statement [Line Items] Statement [Line Items] Gain on property dispositions in discontinued operations Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax 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 September 30, 2018 and December 31, 2017 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 Segment Reporting, Policy [Policy Text Block] Segment Reporting, Policy [Policy Text Block] Expensed pursuit costs Other General and Administrative Expense Selling, General and Administrative Expenses, Policy [Policy Text Block] Selling, General and Administrative Expenses, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Systems Implementation Expense [Policy Text Block] Research, Development, and Computer Software, Policy [Policy Text Block] Revenue Recognition, Policy [Policy Text Block] Revenue Recognition, Policy [Policy Text Block] Systems implementation expense Information Technology and Data Processing Subsequent Events [Abstract] Subsequent Events [Text Block] Subsequent Events [Text Block] Share Repurchase [Abstract] Share Repurchase [Abstract] Class of Treasury Stock [Table] Class of Treasury Stock [Table] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] 2017 Share Repurchase Program [Member] 2017 Share Repurchase Program [Member] 2017 Share Repurchase Program [Member] Common shares [Member] Equity, Class of Treasury Stock [Line Items] Equity, Class of Treasury Stock [Line Items] Stock Repurchase Program, Authorized Amount Stock Repurchase Program, Authorized Amount Stock Repurchased During Period, Shares Stock Repurchased During Period, Shares Assets Held for Sale [Abstract] Assets Held for Sale [Abstract] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Properties sold or classified as held for sale in the prior year and current year to date [Member] Properties sold or classified as held for sale in the prior year and current year to date [Member] Properties sold or classified as held for sale in the prior year and current year to date [Member] Disposal Group, Held-for-sale, Not Discontinued Operations [Member] Disposal Group, Held-for-sale, Not Discontinued Operations [Member] Discontinued Operations, Held-for-sale [Member] Discontinued Operations, Held-for-sale [Member] Held for Sale, Includes Disposal Groups and Discontinued Operations [Member] Held for Sale, Includes Disposal Groups and Discontinued Operations [Member] Includes all assets held for sale as of the end of the period. This includes both discontinued operations and not discontinued operations. Discontinued Operations, Disposed of by Sale [Member] Discontinued Operations, Disposed of by Sale [Member] Discontinued Operations, Held-for-sale or Disposed of by Sale [Member] Discontinued Operations, Held-for-sale or Disposed of by Sale [Member] Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member] Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member] Disposed of by Sale, Discontinued Operations and Not Discontinued Operations [Member] Disposed of by Sale, Discontinued Operations and Not Discontinued Operations [Member] Assets disposed of during the year including discontinued and not discontinued operations. Balance Sheet Disclosures by Disposal Groups [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Number of Real Estate Properties Number of Real Estate Properties Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract] Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract] Land and land improvements Disposal Group, Including Discontinued Operations, Land and Land Improvements Disposal Group, Including Discontinued Operations, Land and Land Improvements Buildings and improvements Disposal Group, Including Discontinued Operations, Building and Improvements Disposal Group, Including Discontinued Operations, Building and Improvements Development in progress Disposal Group, Including Discontinued Operation, Development in Progress Disposal Group, Including Discontinued Operation, Development in Progress 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 depreciation Disposal Group, Including Discontinued Operations, Accumulated Depreciation Disposal Group, Including Discontinued Operations, Accumulated Depreciation Deferred financing and leasing costs, net Disposal Group, Including Discontinued Operation, Intangible Assets Other assets Disposal Group, Including Discontinued Operation, Other Assets Assets held for sale Disposal Group, Including Discontinued Operation, Assets Liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities Stockholders' Equity Attributable to Noncontrolling Interest [Abstract] 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] Limited Partners' common units outstanding Limited Partners' Capital Account, Units Outstanding Market value of common units based on closing price Redeemable Noncontrolling Interest, Equity, Common, Fair Value Equity Method Investments and Joint Ventures [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Equity Method Investee [Member] Equity Method Investee [Member] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] 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] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Philadelphia [Member] Philadelphia [Member] Philadelphia [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Ownership percentage of equity method investment Equity Method Investment, Ownership Percentage Repayments of mortgage loans Repayments of Secured Debt Statement of Stockholders' Equity [Abstract] Common Units [Member] Common Class B [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock [Member] Common Stock [Member] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] AOCI Attributable to Parent [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] Common shares outstanding - Beginning Balance (shares) Common Stock, Shares, Outstanding Beginning Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest General Partner's units outstanding - Beginning Balance (units) General Partners' Capital Account, Units Outstanding Limited Partners' units outstanding - Beginning Balance (units) Net proceeds from the issuance of common shares Stock Issued During Period, Value, New Issues Net proceeds from issuance of common shares (shares) Stock Issued During Period, Shares, New Issues Net income Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest Contributions from partners Partners' Capital Account, Contributions Contributions from partners (units) Partners' Capital Account, Units, Sale of Units 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 loss - foreign currency translation activity Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Other comprehensive income - derivative instruments activity Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Redemption of noncontrolling interests Stock Issued During Period, Value, Conversion of Units Redemption of limited partners common units for common shares - common units (shares) Stock Issued During Period, Shares, Conversion of Units Redemption of limited partners common units for common shares - common units Partners' Capital Account, Exchanges and Conversions Partners' Capital Account, Units, Converted Partners' Capital Account, Units, Converted Common shares outstanding - Ending Balance (shares) General Partner's units outstanding - Ending Balance (units) Limited Partners' units outstanding - Ending Balance (units) Ending Balance 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 Commitments and Contingencies Disclosure [Abstract] Supply Commitment [Table] Supply Commitment [Table] Equity Method Investments [Member] Equity Method Investments [Member] Supply Commitment [Axis] Supply Commitment [Axis] Supply Commitment Arrangement [Domain] Supply Commitment Arrangement [Domain] Supply Commitment [Member] Supply Commitment [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Tenant Improvements [Member] Leasehold Improvements [Member] Building and Building Improvements [Member] Building and Building Improvements [Member] Construction in Progress [Member] Construction in Progress [Member] Land, Buildings and Improvements [Member] Land, Buildings and Improvements [Member] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] American Water Works, Inc [Member] American Water Works, Inc [Member] American Water Works, Inc [Member] Supply Commitment [Line Items] Supply Commitment [Line Items] Leaseable square feet Net Rentable Area 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 Development in Process Deferred leasing costs in development Deferred Costs, Leasing, Gross Remaining amount committed or obligated to pay Supply Commitment, Remaining Minimum Amount Committed Remaining maximum amount committed for tenant improvements Supply Commitment, Remaining Maximum Amount Committed The ceiling amount as of the balance sheet date that the entity must expend to satisfy the terms of disclosed arrangements (excluding long-term commitments) in which the entity must commit resources to supply goods or services to one or more customers. Fee development commitment Other Commitment Costs incurred to date Cost of Goods and Services Sold Income (Numerator) [Abstract] Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Income from continuing operations net of noncontrolling interest - consolidated joint ventures Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent 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 Income from discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Net income available to common shareholders or unitholders Net Income (Loss) Available to Common Stockholders, Basic Weighted Average Units (Denominator) [Abstract] Weighted Average Number of Shares Outstanding, Diluted [Abstract] Weighted Average Number of Shares or Units Outstanding, Basic Weighted Average Number of Shares Outstanding, Basic Dilutive units for long-term compensation plans Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted Average Number of Shares or Units Outstanding, Diluted Weighted Average Number of Shares Outstanding, Diluted Earnings Per Unit, Basic [Abstract] Earnings Per Share, Basic [Abstract] Income from continuing operations Income (Loss) from Continuing Operations, Per Basic Share Income from discontinued operations Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share Income per common share or unit - basic Earnings Per Share, Basic Earnings Per Unit, Diluted [Abstract] Earnings Per Share, Diluted [Abstract] Income from continuing operations Income (Loss) from Continuing Operations, Per Diluted Share Income from discontinued operations Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share Income per common share or unit - diluted Earnings Per Share, Diluted Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] 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 Subsequent Event [Table] Subsequent Event [Table] Business Combination, Separately Recognized Transactions [Axis] Business Combination, Separately Recognized Transactions [Axis] Business Combination, Separately Recognized Transactions [Domain] Business Combination, Separately Recognized Transactions [Domain] 2018 acquisitions [Member] 2018 acquisitions [Member] Real properties purchased in the calendar year 2018. United Kingdom [Member] United Kingdom [Member] United Kingdom Member. Operating Segments [Member] Operating Segments [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Purchase price Property, Plant and Equipment, Additions Supplemental Cash Flow Information [Abstract] Other Significant Noncash Transactions [Table] Other Significant Noncash Transactions [Table] Operating Activities [Axis] Operating Activities [Axis] Operating Activities [Domain] Operating Activities [Domain] Continuing Operations [Member] Continuing Operations [Member] Discontinued Operations [Member] Discontinued Operations [Member] Other Significant Noncash Transaction [Axis] Other Significant Noncash Transaction [Axis] Other Significant Noncash Transaction, Name [Domain] Other Significant Noncash Transaction, Name [Domain] Other Significant Noncash Transactions [Line Items] Other Significant Noncash Transactions [Line Items] 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 Change in accrued development capital expenditures Change in accrued development capital expenditures The change in accrued expenses from prior period for development capital expenditures. Unrealized gain (loss) 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 Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount Conversion of Stock, Amount Converted Conversion of Stock, Amount Converted Property, Plant and Equipment [Abstract] Acquisitions and Dispositions of Real Estate [Table Text Block] Property, Plant and Equipment [Table Text Block] Fair Value Disclosures [Abstract] Fair Value of Financial Instruments, Policy [Policy Text Block] Fair Value of Financial Instruments, Policy [Policy 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] Noncontrolling Interests Noncontrolling Interest Disclosure [Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Land sold to homebuilders [Member] Land sold to homebuilders [Member] Revenue recognized for land sold to homebuilders in the Company's United Kingdom reportable segment. Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Revenue from land sold to homebuilders Revenue from Contract with Customer, Excluding Assessed Tax Supplemental Disclosure to Statements of Cash Flows Cash Flow, Supplemental Disclosures [Text Block] Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Property, Plant and Equipment Disclosure [Text Block] 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] Stockholders' Equity Note Disclosure [Text Block] Prior Period Adjustment [Table] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Restatement [Axis] Restatement [Axis] Restatement [Domain] Restatement [Domain] Previously Reported [Member] Previously Reported [Member] Restatement Adjustment [Member] Restatement Adjustment [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-18 [Member] Accounting Standards Update 2016-18 [Member] Prior Period Adjustments [Line Items] Error Corrections and Prior Period Adjustments Restatement [Line Items] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Joint venture, 2018 sales current quarter [Member] Joint venture, 2018 sales current quarter [Member] Sales in the Company's joint ventures for the current quarter in the fiscal year 2018 Joint venture, 2018 sales [Member] Joint venture, 2018 sales [Member] Sales by the Company's unconsolidated joint ventures during the year ended December 31, 2018. 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, 2017 sales [Member] Joint venture, 2017 sales [Member] Real estate sales related to unconsolidated joint ventures during the fiscal year 2017. Leaseholds and Leasehold Improvements [Member] Leaseholds and Leasehold Improvements [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Other Income [Member] Other Income [Member] Cambridge Medipark Ltd [Member] Cambridge Medipark Ltd [Member] Cambridge Medipark Ltd [Member] Disposal Group, Not Discontinued Operations [Member] Disposal Group, Not Discontinued Operations [Member] Gain on sale of leasehold interests Gain (Loss) on Sale of Investments 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] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] 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 and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [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] Mortgage loans, net Secured Debt Fair value of debt Financial and Nonfinancial Liabilities, Fair Value Disclosure Unsecured notes, net Unsecured Debt Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Real Estate [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 Land held for development Land Available for Development Net real estate Real Estate Investment Property, Net Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents Accounts receivable, net Accounts Receivable, Net Deferred rent receivable, net Deferred Rent Receivables, Net Deferred financing and leasing costs, net of accumulated amortization (September 30, 2018, $165,054; December 31, 2017, $154,762) 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 Prepaid expenses and other assets Prepaid Expense and Other Assets Total assets Assets LIABILITIES Liabilities [Abstract] Credit facilities Long-term Line of Credit Accounts payable Accounts Payable Accrued interest Interest Payable 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; 147,812,321 and 147,450,691 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively Common Stock, Value, Issued General partner’s equity - 147,812,321 and 147,450,691 common units outstanding as of September 30, 2018 and December 31, 2017, respectively General Partners' Capital Account Limited partners’ equity – 3,520,205 common units outstanding as of September 30, 2018 and December 31, 2017 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 partnership - 3,520,205 common units outstanding as of September 30, 2018 and December 31, 2017 Noncontrolling Interest in Operating Partnerships Noncontrolling interest - consolidated joint ventures Noncontrolling Interest in Joint Ventures Total owners' equity Total liabilities, noncontrolling interest - operating partnership and equity Liabilities and Equity Cash and Cash Equivalents [Abstract] Cash and cash equivalents Restricted cash Cash and cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Long-term Purchase Commitment [Table] Long-term Purchase Commitment [Table] Land and Land Improvements [Member] Land and Land 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 Discontinued Operations [Abstract] Discontinued Operations [Abstract] Florida [Member] Florida [Member] Area in the state of Florida which formally included the segments Tampa, Orlando and South Florida. Southeastern PA [Member] Southeastern PA [Member] Southeastern PA DC Metro [Member] DC Metro [Member] DC Metro reportable segment. Discontined Operations Income Statement [Line Items] Expected timing of disposal Disposal Group, Including Discontinued Operation, Description and Timing of Disposal Capital expenditures Capital Expenditure, Discontinued Operations Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] Revenues Disposal Group, Including Discontinued Operation, Revenue Operating expenses Disposal Group, Including Discontinued Operation, Operating Expense Depreciation and amortization Disposal Group, Including Discontinued Operation, Depreciation and Amortization Disposal Group, Including Discontinued Operation, Impairment Expense Disposal Group, Including Discontinued Operation, Impairment Expense Amount of impairment expense attributable to disposal group, including, but not limited to, discontinued operation. Interest and other income Disposal Group, Including Discontinued Operation, Other Income Interest expense Disposal Group, Including Discontinued Operation, Interest Expense Net income before (loss) gain on property dispositions Disposal Group, Including Discontinued Operation, Operating Income (Loss) Gain on property dispositions Net income Noncontrolling interest - operating partnership Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest Income from discontinued operations available to common shareholders Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent 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 Debt Issuance Costs Impairment charges - real estate assets Impairment of real estate, including discontinued operations Impairment of real estate concept including amounts allocated to discontinued operations Equity in earnings of unconsolidated joint ventures Income (Loss) from Equity Method Investments 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] 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 Other liabilities - development service fee Increase (Decrease in Other Operating Liabilities Development Service Fee Amount of increase (decrease) in operating liabilities classified as development service fee. Net cash provided by 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, Distribution, 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 Escrow deposit Payments for Deposits on Real Estate Acquisitions Release of escrows and other Increase (Decrease) in Deposit Assets 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 Share repurchase including shares related to tax withholdings Payments for Repurchase of Common Stock Repayments of mortgage loans Proceeds from credit facility Proceeds from Long-term Lines of Credit Repayments on credit facility Repayments of Long-term Lines of Credit Payments of deferred financing costs Payments of Financing Costs Distribution paid on common shares Payments of Ordinary Dividends, Common Stock Capital contributions Proceeds from Contributed Capital Distributions to partners/noncontrolling interests Payments of Ordinary Dividends, Noncontrolling Interest Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities Net increase in cash, cash equivalents and restricted cash Cash and Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect (Decrease) increase in cash, cash equivalents and restricted cash related to foreign currency translation Effect of Exchange Rate on Cash and Cash Equivalents Cash, cash equivalents and restricted cash at beginning of period Cash, cash equivalents and restricted cash at end of period 2018 (remaining) Operating Leases, Future Minimum Payments, Remainder of Fiscal Year 2019 Operating Leases, Future Minimum Payments, Due in Two Years 2020 Operating Leases, Future Minimum Payments, Due in Three Years 2021 Operating Leases, Future Minimum Payments, Due in Four Years 2022 Operating Leases, Future Minimum Payments, Due in Five Years 2023 and thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total Operating Leases, Future Minimum Payments Due Other Expenses [Abstract] Other Expenses [Abstract] Operating Lease, Expense Operating Leases, Rent Expense, Net 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 Earnings Per Share [Text Block] Earnings Per Share [Text Block] Schedule of Temporary Equity [Table Text Block] Temporary Equity [Table Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Debt Repayment [Member] Debt Repayment [Member] Repayment of debt in full on the maturity date. 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) income Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax 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 (loss) gain related to the ineffective portion recognized in interest expense Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness Interest Rate Derivatives [Abstract] Interest Rate Derivatives [Abstract] Number of interest rate swaps Number of Interest Rate Derivatives Held Fair value Interest Rate Cash Flow Hedge Liability at Fair Value Aggregate notional amount Derivative, Notional Amount Reclassification during next 12 months Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Termination value Assets Needed for Immediate Settlement, Aggregate Fair Value Earnings Per Share, Basic and Diluted [Line Items] Income from continuing operations net of noncontrolling interest Income from discontinued operations net of noncontrolling interest Net income available to common shareholders Weighted Average Shares (Denominator) [Abstract] Dilutive shares for long-term compensation plans Weighted Average Number of Shares or Units Outstanding, Diluted Income from continuing operations Future Minimum Rental Payments Lessee, Operating Lease, Disclosure [Table Text Block] Accumulated Other Comprehensive Income (Loss) Note [Text Block] Comprehensive Income (Loss) Note [Text Block] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Remaining performance obligation Revenue, Remaining Performance Obligation, Amount Remaining performance obligation through years Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Year Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] 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] 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] Unrealized income (loss) Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Reclassification adjustment Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Total accumulated other comprehensive loss Total accumulated other comprehensive loss included in shareholders' equity/owners' equity Impairment Charges [Abstract] Impairment Charges [Abstract] Schedule of Impaired Long-Lived Assets Held and Used [Table] Schedule of Impaired Long-Lived Assets Held and Used [Table] Impaired Long-Lived Assets Held and Used by Type [Axis] Impaired Long-Lived Assets Held and Used by Type [Axis] Impaired Long-Lived Assets Held and Used, Asset Name [Domain] Impaired Long-Lived Assets Held and Used, Asset Name [Domain] Land Held for Development [Member] Land Held for Development [Member] Land Held for Development [Member] Houston [Member] Houston [Member] Houston Reportable Segment Impaired Long-Lived Assets Held and Used [Line Items] Impaired Long-Lived Assets Held and Used [Line Items] Valuation adjustment Real Estate Owned, Valuation Allowance Impairment charges - real estate assets Impairment of Real Estate Assets by Segment [Abstract] Assets by Segment [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] North America [Member] North America [Member] UNITED KINGDOM UNITED KINGDOM 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. Lehigh Central PA [Member] Lehigh Central PA [Member] Lehigh Central PA [Member] Other Segments [Member] Other Segments [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Assets 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 Other Liabilities [Member] Other Liabilities [Member] Liberty Property 18th & Arch [Member] Liberty Property 18th & Arch [Member] Liberty Property 18th & Arch includes both joint ventures that own the Comcast Innovation and Technology Center in Philadelphia Pennsylvania. Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Guarantee Obligations [Member] Guarantee Obligations [Member] 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 Number of hotel rooms Number of hotel rooms Number of hotel rooms in a hotel Anticipated Aggregate Investment Investments in and advances to unconsolidated joint ventures 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 Interest rate swaps [Text Block] Derivative Instruments and Hedging Activities Disclosure [Text Block] Discontinued Operations and Disposal Groups [Abstract] Disposal Groups, Including Discontinued Operations [Table Text Block] Disposal Groups, Including Discontinued Operations [Table Text Block] OPERATING REVENUE Revenues [Abstract] Rental Operating Leases, Income Statement, Lease Revenue Operating expense reimbursement Other Operating Income Development service fee income Revenue from Contract with Customer, Including Assessed Tax 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 Development service fee expense 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 Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal 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 Discontinued operations (including a net gain of $94.9 million and a net gain of $184.7 million on property dispositions for the three and nine months ended September 30, 2018, respectively) 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 Comprehensive income attributable to common shareholders or unitholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Other comprehensive (loss) income - foreign currency translation Other comprehensive income - 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 or unit Basic: Income from discontinued operations Diluted: Distributions per common share or unit Common Stock, Dividends, Per Share, Declared Weighted average number of common shares or units 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 or unitholders Income Amounts Attributable to Parent, Disclosures [Abstract] Income from continuing operations Income from discontinued operations Net income available to common shareholders or unitholders Equity Method Investments and Joint Ventures Disclosure [Text Block] Equity Method Investments and Joint Ventures Disclosure [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 Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Domain] Subsegments Consolidation Items [Domain] Discontinued operations Development Service Fee Income [Member] Development Service Fee Income [Member] Development Service Fee Income [Member] Segment Reconciling Items [Member] Segment Reconciling Items [Member] Intersegment Eliminations [Member] Intersegment Eliminations [Member] 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] Development service fee expense Depreciation and amortization expense Impairment charges - real estate assets Gain on property dispositions General and administrative expense Expensed pursuit costs Systems implementation expense Discontinued operations excluding (loss) gain on property dispositions Other Other Nonoperating Income (Expense) Income from continuing operations Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] 2018 acquisitions current quarter [Member] 2018 acquisitions current quarter [Member] Real estate acquisitions during the current quarter in the fiscal year 2018. Dallas [Member] Dallas [Member] Dallas reportable segment New Jersey [Member] New Jersey [Member] New Jersey business segment [Member] Southern California [Member] Southern California [Member] Operating segment of the company for the properties located in Southern California. Arizona [Member] Arizona [Member] Arizona [Member] 2018 sales current quarter [Member] 2018 sales current quarter [Member] Real estate sales during the current quarter during the fiscal year 2018. 2018 sales [Member] 2018 sales [Member] Sales of real estate during the year ended December 31, 2018. Range [Axis] Range [Axis] Range [Domain] Range [Domain] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Acres of Developable Land Area of Land Gross proceeds Property, Plant and Equipment, Disposals Disclosure of Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Discontinued Operations, Policy [Policy Text Block] Discontinued Operations, Policy [Policy Text Block] Schedule of Adjustments to Previously Reported Financial Statements Schedule of Error Corrections and Prior Period Adjustments [Table Text Block] Derivative Instruments, Gain (Loss) [Table Text Block] Derivative Instruments, Gain (Loss) [Table Text Block] Supplemental Disclosure to Statements of Cash Flows Schedule of Cash Flow, Supplemental Disclosures [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] Market value of common units based on closing price Unit Repurchase [Abstract] Unit Repurchase [Abstract]