Document and Entity Information [Abstract] Document And Entity Information [Abstract] Statement [Table] Statement [Line Items] Entity Registrant Name Document Type Amendment Flag Document Quarterly Report Document Transition Report Document Period End Date Entity Central Index Key Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity File Number Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Title of 12(b) Security Trading Symbol Security Exchange Name Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Common Stock, Shares Outstanding Consolidated Balance Sheets [Abstract] ASSETS Rental Property [Abstract] Rental Property [Abstract] Rental property Land And Leasehold Land And Leasehold Land and leasehold interests Buildings and improvements Tenant improvements Furniture, fixtures and equipment Gross investment in rental property Gross investment in rental property Less - accumulated depreciation and amortization Less - accumulated depreciation and amortization Net book value Total investment in rental property Real Estate Held-for-sale Rental property held for sale, net Net Investment In Rental Property And Rental Property Held For Sale Net Investment In Rental Property And Rental Property Held For Sale Net investment in rental property Cash and cash equivalents, beginning of period Cash and cash equivalents Restricted Cash And Cash Equivalents Total restricted cash Restricted cash Carrying Amount Total investments in unconsolidated joint ventures Carrying Value Investments in unconsolidated joint ventures Unbilled rents receivable, net Other Assets Total deferred charges, goodwill and other assets, net Deferred charges, goodwill and other assets, net Accounts Receivable Net Accounts receivable, net of allowance for doubtful accounts of $1,319 and $1,108 Total assets Total assets LIABILITIES AND EQUITY Senior Notes Senior unsecured notes, net Revolving credit facility Unsecured revolving credit facility and term loans Amount outstanding Outstanding borrowings under the facility Secured Debt Mortgages, loans payable and other obligations, net Dividends and distributions payable Accounts payable, accrued expenses and other liabilities Amount at the balance sheet date including both: (a) rents and other amounts paid in advance by tenants and clients; and (b) security deposits paid in advance to protect the provider of a service, such as a lessor, against damage or nonpayment by the tenant (lessee) during the term of the agreement. Such damages may include physical damage to the property, theft of property, and other contractual breaches. Rents received in advance and security deposits Accrued interest payable Total liabilities Total liabilities Commitments And Contingencies 2009 Commitments and contingencies Redeemable Noncontrolling Interest, Equity, Fair Value Redeemable noncontrolling interests Balance Redeemable noncontrolling interests Equity: Stockholders' Equity Attributable to Parent [Abstract] Mack-Cali Realty Corporation stockholders' equity: Common stock value Common stock, $0.01 par value, 190,000,000 shares authorized, 90,553,357 and 90,320,306 shares outstanding Additional Paid In Capital Additional paid-in capital General Partners' Capital Account General Partner, 90,553,357 and 90,320,306 common units outstanding Limited Partners' Capital Account Limited partners, 9,976,344 and 10,229,349 common units/LTIPs outstanding Retained Earnings Accumulated Deficit Dividends in excess of net earnings Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income (loss) Stockholders' Equity Attributable to Parent Balance Balance Total Mack-Cali Realty Corporation stockholders' equity Partners' Capital Total Mack-Cali Realty, L.P. partners' capital Noncontrolling Interest Items [Abstract] Noncontrolling interests in subsidiaries: Operating Partnership Minority Interest In Joint Ventures Consolidated joint ventures Total noncontrolling interests in subsidiaries Balance, value Balance, value Total noncontrolling interests in subsidiaries Noncontrolling interest's fair value Total equity Balance, value Balance, value Total equity Partners' Capital Attributable to Noncontrolling Interest Noncontrolling interests in consolidated joint ventures Partners' Capital, Including Portion Attributable to Noncontrolling Interest Balance, value Balance, value Total equity Liabilities And Stockholders Equity Total liabilities and equity Allowance for doubtful accounts receivable Allowance for doubtful accounts receivable Common stock, par value per share Common stock, shares authorized Common Stock Shares Outstanding Common stock, shares outstanding General Partners' Capital Account, Units Outstanding General partner common units outstanding Limited Partners' Capital Account, Units Outstanding Limited partners common units outstanding Consolidated Statements Of Operations [Abstract] Revenues Abstract REVENUES Operating Leases, Income Statement, Lease Revenue Revenue from leases Revenues Total revenues Total revenues EXPENSES Real estate taxes Construction and Development Costs Costs of the project incurred Utilities Operating services The aggregate costs including administrative paperwork, real estate brokerage, title, and property management operations. Costs Of Real Estate Services Real estate services expenses Leasing Personnel Costs Leasing Personnel Costs Leasing personnel costs General and administrative Depreciation and amortization Depreciation and amortization Impairment of Real Estate Property impairments Property impairments Impairment Of Land Impairment Of Land Land impairment Land impairments Costs and Expenses Total expenses OTHER (EXPENSE) INCOME Interest expense Interest expense Total Amount of Interest Expense presented in the consolidated statements Investment Income (Loss), Nonoperating Investment Income (Loss), Nonoperating Interest and other investment income (loss) Equity in earnings (loss) of unconsolidated joint ventures Equity in (earnings) loss of unconsolidated joint ventures Equity in earnings (loss) of unconsolidated joint ventures Company's equity in earnings (loss) of unconsolidated joint ventures Gain (Loss) On Change Of Control Of Interests Gain (Loss) On Change Of Control Of Interests Gain on change of control of interests Gain on change of control of interests Realized gains on disposition of rental property Realized gains (losses) and unrealized losses on disposition of rental property, net Gain (Loss) on Disposition of Property Plant Equipment Gain on disposition of developable land Gain on disposition of developable land Gain (Loss) on Sale of Investments Gain on sale of investments in unconsolidated joint ventures Gain (loss) on sale of investment in unconsolidated joint venture Gain on sale of investment in unconsolidated joint venture Extinguishment of Debt, Gain (Loss), Net of Tax Gain (loss) from extinguishment of debt, net Nonoperating Income Expense Including Equity Method Investments Nonoperating Income Expense Including Equity Method Investments Total other income (expense) Net income Net income (loss) Net income (loss) Net income Noncontrolling interest in consolidated joint ventures Add (deduct): Noncontrolling interests in consolidated joint ventures Noncontrolling interests in consolidated joint ventures Noncontrolling interest in operating partnership Noncontrolling interests in Operating Partnership Add (deduct): Noncontrolling interests in Operating Partnership Add (deduct): Noncontrolling interests in Operating Partnership Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Redeemable noncontrolling interests Income Attributed to Noncontrolling Interests Net income (loss) available to common shareholders Net income (loss) available to common shareholders Basic earnings per common share: Earnings Per Share, Basic Net income (loss) available to common shareholders Diluted earnings per common share: Earnings Per Share Diluted Net income (loss) available to common shareholders Net income (loss) available to common shareholders Basic weighted average shares outstanding Basic EPS shares Weighted average common shares Diluted weighted average shares outstanding Weighted average common shares Diluted EPS Shares Weighted Average Limited Partnership Units Outstanding, Basic Basic EPS units Basic weighted average units outstanding Weighted average common units Weighted Average Limited Partnership Units Outstanding, Diluted Diluted EPU Units Diluted weighted average units outstanding Weighted average common unit Consolidated Statements Of Comprehensive Income (Loss) [Abstract] Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive income (loss): Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Net unrealized gain (loss) on derivative instruments for interest rate swaps Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income (loss) Comprehensive Income (Loss), Net Of Tax Attributable To Noncontrolling Interest Joint Venture Partners, Nonredeemable Comprehensive Income (Loss), Net Of Tax Attributable To Noncontrolling Interest Joint Venture Partners, Nonredeemable Comprehensive (income) loss attributable to noncontrolling interests in consolidated joint ventures Comprehensive Income Loss Net Of Tax Attributable To Redeemable Noncontrolling Interest Comprehensive Income Loss Net Of Tax Attributable To Redeemable Noncontrolling Interest Comprehensive (income) loss attributable to redeemable noncontrolling interests Comprehensive Income (Loss), Net Of Tax Attributable To, Noncontrolling Interest Operating Partnerships, Nonredeemable Comprehensive Income (Loss), Net Of Tax Attributable To, Noncontrolling Interest Operating Partnerships, Nonredeemable Comprehensive (income) loss attributable to noncontrolling interests in Operating Partnership Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive income (loss) attributable to common shareholders Consolidated Statements Of Changes In Equity [Abstract] 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] Retained Earnings [Member] Dividends In Excess Of Net Earnings [Member] Noncontrolling Interest [Member] Noncontrolling Interests In Subsidiaries [Member] Shares, Issued Balance, shares Balance, shares Partners' Capital Account, Units Balance, units Balance, units Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest Net income (loss) Common stock dividends Common stock dividends Common unit distributions Common unit distributions Unit distributions Redeemable Noncontrolling Interest Redemption Value Adjustment Redeemable Noncontrolling Interest Redemption Value Adjustment Redemption Value Adjustment (including value adjustment attributable to Add On Investment Agreement) Redeemable noncontrolling interests Noncontrolling Interest, Period Increase (Decrease) Change in noncontrolling interests in consolidated joint ventures Noncontrolling Interest, Increase from Sale of Parent Equity Interest Increase in noncontrolling interest, value Issuance of limited partner common units Minority Interest, Increase (Decrease) From Redemptions Minority Interest, Increase (Decrease) From Redemptions Redemption of common units for common stock, value Redemption of common units for common stock Stock Issued During Period, Shares, Conversion of Units Redemption of common units for common stock, shares Stock Issued During Period, Shares, Long-Term Incentive Plan Vested Stock Issued During Period, Shares, Long-Term Incentive Plan Vested Vested LTIP units, shares Redemption Of Common Units Redemption Of Common Units Redemption of common units Redemption Of Common Units, Shares Redemption Of Common Units, Shares Redemption of common units, shares Shares issued under Dividend Reinvestment and Stock Purchase Plan, value Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings Shares issued under Dividend Reinvestment and Stock Purchase Plan, value Shares issued under Dividend Reinvestment and Stock Purchase Plan Stock Dividends, Shares Shares issued under Dividend Reinvestment and Stock Purchase Plan, shares Stock Issued During Period, Value, Restricted Stock Award, Gross Directors' deferred compensation plan, value Directors' deferred compensation plan Stock Issued During Period, Shares, Restricted Stock Award, Gross Directors' deferred compensation plan, shares Adjustments To Additional Paid In Capital Sharebased Compensation Value Adjustments To Additional Paid In Capital Sharebased Compensation Value Stock compensation, value Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Stock compensation, shares Stock Issued During Period, Value, Share-based Compensation, Forfeited Cancellation of restricted shares, value Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Cancellation of restricted shares, shares Shares forfeited and cancelled Other Comprehensive Income (Loss), Net of Tax Other comprehensive income (loss) Noncontrolling Interest, Increase (Decrease) from Subsidiary Equity Issuance Noncontrolling Interest, Increase (Decrease) from Subsidiary Equity Issuance Rebalancing of ownership percentage between parent and subsidiaries Consolidated Statements Of Cash Flows [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES Adjustments to reconcile net income (loss) to net cash provided by Operating activities: Depreciation and amortization, including related intangible assets Amortization Of Deferred Stock Units Amortization Of Deferred Stock Units Amortization of directors deferred compensation stock units Stock compensation Amortization of stock compensation Amortization of deferred financing costs Amortization Of Debt Discount And Mark-To-Market Amortization Of Debt Discount And Mark-To-Market Amortization of debt discount and mark-to-market Write off of Deferred Debt Issuance Cost Write-off of unamortized deferred financing costs Write-off of unamortized deferred finance costs related to early extinguishment Equity Method Investment Dividends Or Distributions Distributions of cumulative earnings from unconsolidated joint ventures Realized Gains Loss On Disposition Of Assets, Including Discontinued Operations Realized Gains Loss On Disposition Of Assets, Including Discontinued Operations Realized (gains) losses and unrealized losses on disposition of rental property, net Gains (Losses) on Extinguishment of Debt (Gain)Loss from extinguishment of debt Loss from extinguishment of debt, net Changes in operating assets and liabilities: Increase Decrease In Unbilled Rent Receivables Increase Decrease In Unbilled Rent Receivables Increase in unbilled rents receivable, net Increase in deferred charges and other assets, net Increase in deferred charges, goodwill and other assets (Increase) decrease in accounts receivable, net (Increase) decrease in accounts receivable, net Increase (decrease) in accounts payable, accrued expenses and other liabilities Increase in accounts payable, accrued expenses and other liabilities The net change during the reporting period in the amount at the balance sheet date including both: (a) rents and other amounts paid in advance by tenants and clients; and (b) security deposits paid in advance to protect the provider of a service, such as a lessor, against damage or nonpayment by the tenant (lessee) during the term of the agreement Increase Decrease In Rents Received In Advance And Security Deposits Decrease in rents received in advance and security deposits Decrease in accrued interest payable Decrease in accrued interest payable Net cash provided by operating activities Net cash provided by operating activities CASH FLOWS FROM INVESTING ACTIVITIES Payments to Acquire Businesses, Net of Cash Acquired Rental property acquisitions and related intangibles Payments to Acquire and Develop Real Estate Rental property additions and improvements Purchase price of property Payments To Develop Property And Other Related Costs Payments To Develop Property And Other Related Costs Development of rental property and other related costs Net Sales Proceeds Proceeds from the sales of rental property Proceeds from Divestiture of Interest in Joint Venture Proceeds from the sale of investments in unconsolidated joint ventures Proceeds from Collection of Loans Receivable Repayment of notes receivable Investment in unconsolidated joint ventures Investment in unconsolidated joint ventures This item represents the amount of distributions in excess of net earnings, which represents a return of investment, received from unconsolidated joint ventures and subsidiaries; these investments are accounted for under the equity method of accounting. Distributions In Excess Of Cumulative Earnings From Jvs Distributions in excess of cumulative earnings from unconsolidated joint ventures Net cash used in investing activities Net cash (used in) provided by investing activities CASH FLOW FROM FINANCING ACTIVITIES Borrowings from revolving credit facility Repayment of revolving credit facility and money market loans Repayment of revolving credit facility Payment for borrowings Proceeds From Unsecured Term Loan Proceeds From Unsecured Term Loan Repayment of unsecured term loan Proceeds from Issuance of Secured Debt Proceeds from mortgages and loans payable Repayment of mortgages, loans payable and other obligations Repayment of mortgages, loans payable and other obligations Payments To Acquire Minority Interest Payments To Acquire Minority Interest Acquisition of noncontrolling interests Proceeds From Issuance Of Redeemable Noncontrolling Interests Proceeds From Issuance Of Redeemable Noncontrolling Interests Issuance of redeemable noncontrolling interests, net Payment of financing costs Payment of financing costs Proceeds from (Payments to) Noncontrolling Interests (Contributions) Distributions to noncontrolling interests Payment of dividends and distributions Payment of dividends and distributions Net cash provided used in financing activities Net cash used in financing activities Net (decrease) increase in cash and cash equivalents Net increase (decrease) in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents and restricted cash, end of period Cash, cash equivalents and restricted cash, beginning of period Organization And Basis Of Presentation [Abstract] Organization And Basis Of Presentation [Table] Organization And Basis Of Presentation [Table] Organization And Basis Of Presentation [Line Items] Organization And Basis Of Presentation [Line Items] Organization Consolidation And Presentation Of Financial Statements Disclosure TextBlock Organization And Basis Of Presentation Significant Accounting Policies [Abstract] Significant Accounting Policies [Table] Significant Accounting Policies [Table] Significant Accounting Policies [Line Items] Significant Accounting Policies [Line Items] Significant Accounting Policies Textblock Significant Accounting Policies Recent Transactions [Abstract] Recent Transactions [Abstract] Recent Transactions [Table] Recent Transactions [Table] Recent Transactions [Line Items] Recent Transactions [Line Items] Recent Transactions [Text Block] Recent Transactions [Text Block] Recent Transactions Investments In Unconsolidated Joint Ventures [Abstract] Investments In Unconsolidated Joint Ventures [Table] Investments In Unconsolidated Joint Ventures [Table] Investments In Unconsolidated Joint Ventures [Line Items] Investments In Unconsolidated Joint Ventures [Line Items] Equity Method Investments Disclosure TextBlock Investments In Unconsolidated Joint Ventures Deferred Charges, Goodwill And Other Assets, Net [Abstract] Deferred Charges, Goodwill And Other Assets [Table] Deferred Charges, Goodwill And Other Assets [Table] Deferred Charges, Goodwill And Other Assets [Line Items] Deferred Charges, Goodwill And Other Assets [Line Items] Deferred Costs Capitalized Prepaid And Other Assets Disclosure TextBlock Deferred Charges, Goodwill And Other Assets, Net Restricted Cash [Abstract] Restricted Cash [Table] Restricted Cash [Table] Restricted Cash [Line Items] Restricted Cash [Line Items] Restricted Assets Disclosure [Text Block] Restricted Cash Debt Disclosure [Abstract] Debt Disclosure [Table] Debt Disclosure [Table] Debt Disclosure [Line Items] Debt Disclosure [Line Items] Senior Unsecured Notes [Text Block] Senior Unsecured Notes [Text Block] Senior Unsecured Notes Schedule Of Line Of Credit Facilities TextBlock Unsecured Revolving Credit Facility And Term Loans Mortgages And Notes Payable [Text Block] Mortgages, Loans Payable And Other Obligations Employee Benefit 401(k) Plans [Abstract] Compensation And Retirement Disclosure [Table] Compensation And Retirement Disclosure [Table] Compensation And Retirement Disclosure [Line Items] Compensation And Retirement Disclosure [Line Items] GeneralDiscussionOfPensionAndOtherPostretirementBenefitsAbstract Employee Benefit 401(k) Plans Disclosure Of Fair Value Of Assets And Liabilities [Abstract] Fair Value Disclosures [Table] Fair Value Disclosures [Table] Fair Value Disclosures [Line Items] Fair Value Disclosures [Line Items] Fair Value Disclosures TextBlock Disclosure Of Fair Value Of Assets And Liabilities Commitments And Contingencies [Abstract] Commitments And Contingencies [Table] Commitments and Contingencies [Table] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Commitments and Contingencies Disclosure Textblock Commitments And Contingencies Tenant Leases [Abstract] Leases [Table] Leases [Table] Leases [Line Items] Leases [Line Items] Leases Of Lessor Disclosure TextBlock Tenant Leases Redeemable Noncontrolling Interests [Abstract] Redeemable Noncontrolling Interest, by Legal Entity [Table] Redeemable Noncontrolling Interest [Line Items] Redeemable Noncontrolling Interests [Text Block] Redeemable Noncontrolling Interests [Text Block] Redeemable Noncontrolling Interests Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital [Abstract] Stockolders' Equity [Table] Stockolders Equity [Table] Stockolders Equity [Line Items] Stockolders Equity [Line Items] Stockholders Equity Note Disclosure TextBlock Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital Noncontrolling Interests In Subsidiaries [Abstract] Noncontrolling Interest [Table] Noncontrolling Interest [Line Items] Minority Interest Disclosure TextBlock Noncontrolling Interests In Subsidiaries Segment Reporting [Abstract] Segment Reporting Information [Table] Segment Reporting Information [Table] Segment Reporting Information [Line Items] Segment Reporting Disclosure Textblock Segment Reporting Property, Plant and Equipment, Policy [Text Block] Rental Property Real Estate Held for Development and Sale, Policy Rental Property Held For Sale Equity Method Investments, Policy Investments In Unconsolidated Joint Ventures Cash and Cash Equivalents, Policy [Text Block] Cash And Cash Equivalents Disclosure of entity's accounting policy for costs incurred in connection with obtaining finance. Deferred Financing Costs Policy Text Block Deferred Financing Costs Disclosure of the entity's accounting policy for costs incurred in connection with leases. Deferred Leasing Costs Policy Text Block Deferred Leasing Costs/Leasing Personnel Costs Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Goodwill Derivatives, Policy [Text Block] Derivative Instruments Revenue Recognition, Policy [Text Block] Revenue Recognition Allowance For Doubtful Accounts Policy [Policy Text Block] Allowance For Doubtful Accounts Policy [Policy Text Block] Allowance For Doubtful Accounts Income Tax, Policy [Text Block] Income And Other Taxes Earnings Per Share, Policy [Text Block] Earnings Per Share Or Unit Disclosure of the entity's accounting policy for declaring and paying dividends and distributions. Dividends And Distributions Payable Policy Text Block Dividends And Distributions Payable Disclosure of the accounting policy for costs incurred in connection with stock issuances. Issuance Costs Policy Text Block Costs Incurred For Stock Issuances Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Stock Compensation Other Comprehensive Income Policy [Text Block] Other Comprehensive Income Policy Text Block Other Comprehensive Income (Loss) Redeemable Noncontrolling Interests [Policy Text Block] Redeemable Noncontrolling Interests [Policy Text Block] Redeemable Noncontrolling Interests Fair Value Measurement, Policy [Policy Text Block] Fair Value Hierarchy New Accounting Pronouncements, Policy [Policy Text Block] Impact Of Recently-Issued Accounting Standards Schedule Of Rental Property Improvements, Not In Service [Text Block] Schedule Of Rental Property Improvements, Not In Service [Text Block] Schedule Of Rental Property Improvements Schedule of Estimated Useful Lives of Assets [Text Block] Schedule of Estimated Useful Lives of Assets [Text Block] Estimated Useful Lives Of Assets Schedule of Real Estate Properties [Table] Real Estate Properties [Line Items] Schedule of Business Acquisitions, by Acquisition [Table Text Block] Schedule Of Properties Acquired Schedule of Purchase Price Allocation [Table Text Block] Schedule Of Acquisition Cost Allocated To Net Assets Acquired Schedule Of Consolidation Amounts [Table Text Block] Schedule Of Consolidation Amounts [Table Text Block] Schedule Of Net Assets Recorded Upon Consolidation Schedule Of Real Estate Properties Sold [Table TextBlock] Schedule Of Real Estate Properties Sold [Table TextBlock] Schedule Of Disposed Properties Schedule Of Unconsolidated Joint Ventures [Table Text Block] Schedule Of Unconsolidated Joint Ventures [Table Text Block] Summary Of Unconsolidated Joint Ventures Summary Of Company's Equity In Earnings (Loss) Of Unconsolidated Joint Ventures Summary Of Company's Equity In Earnings (Loss) Of Unconsolidated Joint Ventures Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Other Assets [Table Text Block] Schedule Of Deferred Charges, Goodwill And Other Assets Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule Of Fair Value Of The Derivative Financial Instruments Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Schedule Of Cash Flow Hedging, Derivative Financial Instruments On The Income Statement Schedule of Restricted Cash and Cash Equivalents [Table Text Block] Schedule Of Restricted Cash Schedule of Long-term Debt Instruments [Table] Debt Instrument [Line Items] Schedule of Senior Unsecured Notes [Table Text Block] Summary Of Senior Unsecured Notes Schedule Of Defined Leverage Ratio, Including Interest Rate, Alternate Base Rate Loans And Facility Fee [Table Text Block] Schedule Of Defined Leverage Ratio, Including Interest Rate, Alternate Base Rate Loans And Facility Fee [Table Text Block] Schedule Of Defined Leverage Ratio, Including Interest Rate, Alternate Base Rate Loans, And Facility Fee Schedule Of Unsecured Credit Rating, Alternate Base Rate Loans And Credit Facility Fee, Operating Partnerships [Table Text Block] Schedule Of Unsecured Credit Rating, Alternate Base Rate Loans And Credit Facility Fee, Operating Partnerships [Table Text Block] Schedule Of Interest Rates On Outstanding Borrowings, Alternate Base Rate Loans, And Facility Fee Schedule Of Unsecured Credit Rating And Facility Fee, Operating Partnerships [Table Text Block] Schedule Of Unsecured Credit Rating And Facility Fee, Operating Partnerships [Table Text Block] Schedule Of Unsecured Credit Rating And Facility Fee Schedule Of Defined Leverage Ratio [Table Text Block] Schedule Of Defined Leverage Ratio [Table Text Block] Schedule Of Defined Leverage Ratio Schedule Of Unsecured Credit Rating, Operating Partnerships [Table Text Block] Schedule Of Unsecured Credit Rating, Operating Partnerships [Table Text Block] Schedule Of Interest Rate On Outstanding Borrowings Payable Schedule of Secured Debt [Table Text Block] Schedule of Secured Debt [Table Text Block] Summary Of Mortgages, Loans Payable And Other Obligations Commitments And Contingencies Disclosure [Table] Commitments And Contingencies Disclosure [Table] Commitments And Contingencies Disclosure [Line Items] Commitments And Contingencies Disclosure [Line Items] Schedule Of Future Minimum Rental Payments For Operating Leases [Table Text Block] Future Minimum Rental Payments Of Ground Leases Schedule Of Future Minimum Rentals Under Non-cancelable Operating Lease [Text Block] Schedule Of Future Minimum Rentals Under Non-cancelable Operating Lease [Text Block] Future Minimum Rentals To Be Received Under Non-Cancelable Operating Leases Redeemable Noncontrolling Interest [Table Text Block] Schedule Of Changes In The Value Of The Redeemable Noncontrolling Interests Schedule of Stockholders Equity [Table Text Block] Schedule Of General Partner Capital Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule Of Stock Option Plans Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule Of Weighted Average Assumptions Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Schedule Of Restricted Stock Awards Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule Of Reconciliation Of Shares Used In Basic EPS Calculation To Shares Used In Diluted EPS Calculation Minority Interest [Table Text Block] Minority Interest [Table Text Block] Schedule Of Activity Of Noncontrolling Interests Schedule of Other Ownership Interests [Text Block] Changes In Noncontrolling Interests Of Subsidiaries Schedule of Segment Reporting Information, by Segment [Text Block] Schedule Of Selected Results Of Operations And Asset Information Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Schedule Of Reconciliation Of Net Operating Income To Net Income Available To Common Shareholders Real Estate, Type of Property [Axis] Mortgage Loans On Real Estate Name Property Type [Domain] Real Estate [Domain] Unconsolidated Joint Venture Office Buildings [Member] Unconsolidated Joint Venture Office Buildings [Member] Unconsolidated Joint Venture Office Buildings [Member] Multi-Family Properties [Member] Multiple Family Properties [Member] Multi-Family Properties [Member] Unconsolidated Joint Venture Multiple Family Properties [Member] Unconsolidated Joint Venture Multiple Family Properties [Member] Unconsolidated Joint Venture Multi-Family Properties [Member] Unconsolidated Joint Venture Office/Flex Buildings And Hotel [Member] Unconsolidated Joint Venture Office Flex Buildings And Hotel [Member] Unconsolidated Joint Venture Office/Flex Buildings And Hotel [Member] Parking/Retail [Member] Parking Retail [Member] Parking/Retail [Member] Unconsolidated Joint Venture Parking/Retail Buildings [Member] Unconsolidated Joint Venture Parking Retail Buildings [Member] Unconsolidated Joint Venture Parking/Retail Buildings [Member] Land [Member] Land [Member] General Partner Ownership Percentage General Partner Ownership Percentage Percentage of ownership interest Real Estate Property Owned and Investment Interest Real Estate Property Owned and Investment Interest Number of properties owned or investment interests Real Estate Property Owned and Investment Interest, Area Real Estate Property Owned and Investment Interest, Area Aggregate square feet of the property owned or investment interest Number Of Tenants Number Of Tenants Number of tenants Number Of Units Number of Apartment Units Number of units Real Estate Property Owned or Investment Interest, Number of Location Real Estate Property Owned or Investment Interest, Number of Location Number of states where properties are located Consolidated Joint Ventures Real Estate Assets Consolidated Joint Ventures Real Estate Assets Consolidated joint ventures, total real estate assets Consolidated Joint Ventures Mortgages Consolidated Joint Ventures Mortgages Consolidated joint ventures, mortgages Consolidated Joint Ventures Other Liabilities Consolidated Joint Ventures Other Liabilities Consolidated joint ventures, other liabilities Capitalized Development, Construction Salaries And Other Related Expenses Capitalized Development, Construction Salaries And Other Related Expenses Capitalized development and construction salaries and other related costs Maximum Period After Cessation Of Major Construction Activity That Projects Are Considered Complete Maximum Period After Cessation Of Major Construction Activity That Projects Are Considered Complete Maximum period after cessation of major construction activity that projects are considered complete Threshold Of Investment Value For Discontinuation Of Equity Method Accounting Threshold Of Investment Value For Discontinuation Of Equity Method Accounting Threshold of investment value for discontinuation of equity method accounting Amortization of Financing Costs Amortization of deferred financing costs Amortization of Deferred Leasing Fees Deferred leasing costs Deferred tax asset Valuation allowance Material Adjustment Amount Material Adjustment Amount Income taxes, material adjustment amount The number of common units outstanding. Common Units Outstanding Balance, Ending, Common Units Balance, Beginning, Common Units Common units outstanding Long-Term Incentive Plan Units Outstanding Long-Term Incentive Plan Units Outstanding Balance, Ending, LTIP Units Balance, Beginning, LTIP Units LTIP units outstanding Dividends Payable, Date of Record Distributions payable, record date Dividends Payable, Date Declared Distributions payable, approved date Common Stock Dividends And Common Unit Distributions Per Share Common Stock Dividends And Common Unit Distributions Per Share Common stock dividends and common unit distributions per share Restricted Stock Expense Stock compensation expense Dividends Payable, Date to be Paid, Day, Month and Year Distributions payable, pay date Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Increase (decrease) to valuation allowance Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Federal income tax rate New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income Adjustment to retained earnings Long-Term Incentive Plan Unit, Value Long-Term Incentive Plan Unit, Value LTIP value Dividends, Common Stock, Cash Dividends paid Property, Plant and Equipment [Line Items] Land and Land Improvements Land held for development (including pre-development costs, if any) Development And Construction In Progress, Including Land Development And Construction In Progress, Including Land Development and construction in progress, including land Property, Plant and Equipment, Gross Total Buildings And Improvements, Net Of Accumulated Depreciation Buildings And Improvements, Net Of Accumulated Depreciation Buildings and improvement Land Land Schedule of Property, Plant and Equipment [Table] Statistical Measurement [Axis] Range [Member] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Property, Plant and Equipment by Type [Axis] Property Plant And Equipment Type [Domain] Property, Plant and Equipment, Type [Domain] Building And Building Improvements [Member] Buildings And Improvements [Member] Furniture And Fixtures [Member] Furniture, Fixtures And Equipment [Member] Property, Plant and Equipment, Useful Life Estimated useful lives of assets Number of real estate properties Number of properties Area Of Real Estate Property Area of property (in square feet) Rentable Square Feet (sf) Area of property (in square feet) Number Of Properties In Which Additional Interest Was Acquired During Period Number Of Properties In Which Additional Interest Was Acquired During Period Number of properties in which additional interest was acquired during period Other Significant Noncash Transaction, Value of Consideration Given Acquisition and other investment fundings handled by intermediary Preferred Units, Issued Preferred units shares issued Equity Method Investment, Ownership Percentage Percentage of interest in venture Company's Effective Ownership % Preferred Unit, Dividend Rate, Percentage Preferred Unit, Dividend Rate, Percentage Preferred unit annual rate Percentage Of Additional Interest Acquired Percentage Of Additional Interest Acquired Percentage of additional interest acquired Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net Net assets acquired Net assets Number Of Stories In Real Estate Property Number Of Stories In Real Estate Property Number of stories Mortgage Loan Maturity Date Mortgage Loan Maturity Date Mortgage loan, maturity date Property Debt, Maturity Date Property Debt, Interest Rate, Spread Over LIBOR Spread over LIBOR Interest Rate - Applicable Basis Points Above LIBOR Mortgage Loans on Real Estate Balance Mortgage loan Carrying Amount of Mortgages Repayment Of Mortgage Loans On Real Estate Repayment Of Mortgage Loans On Real Estate Repayment of mortgage loans Proceeds from Issuance of Debt Issuance of loan Long-term Debt, Gross Loan balance Principal balance outstanding Proceeds from Sale of Real Estate Held-for-investment Net Sales Proceeds Sales proceeds Gain (Loss) on Disposition of Real Estate, Discontinued Operations Realized Gains (losses)/Unrealized Losses, net Valuation Allowance for Impairment of Recognized Servicing Assets, Disposals Valuation impairment charge Schedule of Preferred Units [Table] Preferred Units [Line Items] Contribution Value Equity Units Limited Partnership Interest Contribution Value Equity Units Limited Partnership Interest Contributed amount to obtain equity units Incremental Contribution Value Equity Units Limited Partnership Interest Incremental Contribution Value Equity Units Limited Partnership Interest Incremental closing payments, Limited Partnership interest Contributed Equity Value Contributed Equity Value Contributed equity value Right Of First Refusal To Invest In Preferred Units, Amount Right Of First Refusal To Invest In Preferred Units, Amount Right of first refusal to invest Gain on Sale of Investments Gain on sale Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Line Items] Number Of Properties Acquired Number Of Properties Acquired Number of Buildings, Acquired Area Of Real Estate Property Acquired Area Of Real Estate Property Acquired Rentable Square Feet, Acquired Business Combination, Consideration Transferred Acquisition cost Business Acquisition, Purchase Price Allocation, Land Land and leasehold interest Business Acquisition, Purchase Price Allocation, Buildings Buildings and improvements and other assets, net Buildings and improvements and other assets Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Above Market Leases Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Above Market Leases Above market lease values Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, In Place Leases Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, In Place Leases In-place lease values Business Acquisition, Purchase Price Allocation, Assets Acquired Sub Total Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Below Market Leases Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Below Market Leases Less: Below market lease values Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value Less: Noncontrolling interests Non-controlling interest Finite-Lived Intangible Asset, Useful Life Amortization period Business Acquisition, Purchase Price Allocation, Liabilities Assumed Less: Debt Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest Net assets recorded upon consolidation Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Number Of Buildings On Properties Sold Number of buildings on properties sold Number of Buildings, Disposed Number Of Properties Disposed Number Of Properties Disposed Number of properties disposed Area Of Real Estate Property Sold Area Of Real Estate Property Sold Rentable Square Feet, Disposed Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Net Value Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Net Value Net Carrying Value Internal Rate of Return Internal rate of return Internal rate of return Gain (Loss) On Disposition Of Real Estate Discontinued Operations, Net Of Unrealized Gain (Losses) Gain (Loss) On Disposition Of Real Estate Discontinued Operations, Net Of Unrealized Gain (Losses) Totals Proceeds From Sale Of Real Estate Held For Investment, Held By A Qualified Intermediary Proceeds From Sale Of Real Estate Held For Investment, Held By A Qualified Intermediary Net sales proceeds held by qualified intermediary Debt Instrument, Number Of Extension Options Debt Instrument, Number Of Extension Options Number of extension options Debt Instrument Extension Period Debt Instrument Extension Period Loan extension period Financing Receivable, Gross Mortgage receivable Proceeds from Sale of Real Estate Proceeds from sale of properties Payments To Acquire And Develop Real Estate, Funds From Proceeds From Sale Of Real Estate Held For Investment, Held By A Qualified Intermediary Payments To Acquire And Develop Real Estate, Funds From Proceeds From Sale Of Real Estate Held For Investment, Held By A Qualified Intermediary Funds from qualified intermediary Schedule of Equity Method Investments [Table] Variable Interest Entities [Axis] Classification Of Variable Interest Entity [Domain] Variable Interest Entity, Classification [Domain] Variable Interest Entity Not Primary Beneficiary [Member] Variable Interest Entity [Member] Unconsolidated Joint Venture Retail Buildings [Member] Unconsolidated Joint Venture Retail Buildings [Member] Unconsolidated Joint Venture Retail Buildings [Member] Unconsolidated Joint Venture Hotel [Member] Unconsolidated Joint Venture Hotel [Member] Unconsolidated Joint Venture Hotel [Member] Unconsolidated Joint Venture Development Projects [Member] Unconsolidated Joint Venture Development Projects [Member] Unconsolidated Joint Venture Development Projects [Member] Unconsolidated Joint Venture Land Parcels [Member] Unconsolidated Joint Venture Land Parcels [Member] Unconsolidated Joint Venture Land Parcels [Member] Unconsolidated Joint Ventures [Member] Unconsolidated Joint Ventures [Member] Unconsolidated Joint Ventures [Member] Schedule of Equity Method Investments [Line Items] Area Of Mixed Use Property Area Of Mixed Use Property Area of mixed use project (in square feet) Maximum borrowing capacity Borrowing capacity under the credit facility Management, Leasing, Development And Other Services Fees Management, Leasing, Development And Other Services Fees Management, leasing, development and other services fees Due from Joint Ventures Accounts receivable due from unconsolidated joint ventures Number Of Variable Interest Entities Number Of Variable Interest Entities Number of VIEs Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Maximum exposure to loss Variable Interest Entity, Entity Estimated Future Funding Commitments Variable Interest Entity, Entity Estimated Future Funding Commitments Estimated future funding commitments Property Debt, Interest Rate Interest rate Interest rate of senior unsecured notes Long-term Line of Credit, Maximum Guaranteed Amount Long-term Line of Credit, Maximum Guaranteed Amount Maximum guaranteed amount Long-term Line of Credit, Guaranteed Amount Long-term Line of Credit, Guaranteed Amount Guaranteed amount Name of Property [Axis] Real Estate And Accumulated Depreciation Name Of Property [Domain] Name of Property [Domain] The Shops At Forty Park Property [Member] Shops At Forty Park Property [Member] The Shops At 40 Park Property [Member] Lofts At 40 Park Property [Member] Lofts At Forty Park Property [Member] Lofts At 40 Park Property [Member] Metropolitan Property [Member] Metropolitan Property [Member] Metropolitan Property [Member] Investment, Name [Axis] Equity Method Investee Name [Domain] Equity Method Investee, Name [Domain] Red Bank Corporate Plaza, L.L.C. [Member] Red Bank Corporate Plaza L L C [Member] Red Bank [Member] 12 Vreeland Associates, L.L.C. [Member] Twelve Vreeland Associates L L C [Member] 12 Vreeland Road [Member] Metropolitan At 40 Park [Member] Metropolitan At40 Park [Member] Metropolitan At 40 Park [Member] RiverTrace At Port Imperial [Member] Rivertrace At Port Imperial [Member] RiverTrace At Port Imperial [Member] Offices At Crystal Lake [Member] Offices At Crystal Lake [Member] Offices At Crystal Lake [Member] Riverwalk Retail [Member] Riverwalk Retail [Member] Riverwalk Retail [Member] Hyatt Regency Jersey City [Member] Hyatt Regency Jersey City [Member] Hyatt Regency Jersey City [Member] Riverpark At Harrison [Member] Riverpark At Harrison [Member] Riverpark At Harrison [Member] Station House [Member] Station House [Member] Station House [Member] Urby At Harborside [Member] Urby At Harborside [Member] Urby At Harborside [Member] PI North - Land [Member] Pi North Land [Member] PI North - Land [Member] Liberty Landing [Member] Liberty Landing [Member] Liberty Landing [Member] Hillsborough 206 Holdings, L.L.C. [Member] Hillsborough Two Hundred Six Holdings L L C [Member] Hillsborough 206 [Member] Crystal House Apartments Investors LLC [Member] Crystal House Apartments Investors L L C [Member] Crystal House [Member] PI North - Riverwalk [Member] Pi North Riverwalk [Member] PI North - Riverwalk C [Member] Marbella II [Member] Marbella Ii [Member] Marbella II [Member] Other Joint Ventures [Member] Other Joint Ventures [Member] Other [Member] Residual Ownership Interest Residual Ownership Interest Residual ownership interest Indirect Ownership Percentage Indirect Ownership Percentage Indirect ownership interest Debt Instrument Extension Fee Percentage Debt Instrument Extension Fee Percentage Extension fee Percentage Of Interest In Developable Land Percentage Of Interest In Developable Land Percentage of interest in developable land Debt Instrument, Interest Rate, Effective Percentage Effective rate Number Of Units Available For Development Number Of Units Available For Development Number of units available for development Number Of Approved Units Available For Development Number Of Approved Units Available For Development Number of approved units available for development Mortgage loan, maturity date Loan maturity date Maturity date of the senior unsecured notes Percentage Of Interest Sold Percentage Of Interest Sold Percentage of interest sold Equity Method Investment, Amortization Of Basis Difference Equity Method Investment, Amortization Of Basis Difference Amortization of basis difference Income From Sale Of Economic Tax Credit Certificate Income From Sale Of Economic Tax Credit Certificate Economic tax credit certificate income Period Of Venture Agreement With Third Party Period Of Venture Agreement With Third Party Period of venture agreement to sell economic tax credit Proceeds From Economic Tax Credit, Annual Proceeds From Economic Tax Credit, Annual Annual proceeds from economic tax credit Proceeds From Economic Tax Credit, Total Proceeds From Economic Tax Credit, Total Total proceeds from economic tax credit Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Line Items] Derivative Liability, Notional Amount Derivative notional amount Derivative, Net Hedge Ineffectiveness Gain (Loss) Ineffective gain (loss) in interest expense Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Estimated additional amount to be reclassified to interest expense Derivative Liability, Fair Value, Gross Liability Net liability Derivative, Notional Amount Notional Value Derivative, Terminated Notional Amount Derivative, Terminated Notional Amount Terminated notional amount Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Amount of Gain or (Loss) Recognized in Income on Derivative (Reclassification for Forecasted Transactions No Longer Probable of Occurring) Reclassification of a gain Derivative, Net Liability Position, Aggregate Fair Value Derivatives, Net liability position Collateral Already Posted, Aggregate Fair Value Collateral for fair value of assets Deferred Costs, Leasing, Gross Deferred leasing costs Deferred Finance Costs, Gross Deferred financing costs - unsecured revolving credit facility Deferred Costs, Gross Deferred Costs, Gross Deferred charges, net Accumulated Amortization Leasing And Financing Costs Accumulated Amortization Leasing And Financing Costs Accumulated amortization Deferred charges, net Deferred charges, net Loans and Leases Receivable, Net Amount Notes receivable Finite-Lived Intangible Asset, Acquired-in-Place Leases In-place lease values, related intangibles and other assets, net Business Acquisition, Purchase Price Allocation, Goodwill Amount Goodwill Assets Right-Of-Use Assets Right-Of-Use Right of use assets Prepaid expenses and other assets, net Assets Right Of Use, Liability Assets Right Of Use, Liability Liability Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivative Asset Asset Derivatives Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Amount of Gain or (Loss) Recognized in OCI on Derivative Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income Security Deposit Security deposits Escrow Deposit Escrow and other reserve funds Debt Instrument, Unamortized Discount Adjustment for unamortized debt discount Adjustment for unamortized debt discount Unamortized Deferred Financing Costs Unamortized Deferred Financing Costs Unamortized deferred financing costs Unamortized deferred financing costs Long-term Debt Total indebtedness Total senior unsecured notes, net Line of Credit Facility [Table] Line of Credit Facility [Line Items] Unsecured Long-term Debt, Noncurrent Unsecured term loan, net Derivative, Average Variable Interest Rate Interest rate swap Line of Credit Facility, Lending Institutions Number Line of Credit Facility, Lending Institutions Number Number of lending institutions Line of Credit Facility, Expiration Date Credit facility maturity date Line Of Credit Facility Extension Period Line Of Credit Facility Extension Period Credit facility, extension period Debt Instrument Covenant Compliance, Leverage Ratio Debt Instrument Covenant Compliance, Leverage Ratio Leverage ratio Line of Credit Facility, Covenant Terms Terms of the unsecured facility Line of Credit Facility, Dividend Restrictions Terms of dividend restriction Debt Instrument, Term Loan period Debt Instrument, Initial Term Commitment Percentage Borrowed Debt Instrument, Initial Term Commitment Percentage Borrowed Minimum percentage of initial borrowing Debt Instrument, Term Commitment Fee Per Annum Debt Instrument, Term Commitment Fee Per Annum Term commitment fee percent Line of Credit Facility, Maximum Borrowing Capacity That May Be Elected After Effective Loan Date Line of Credit Facility, Maximum Borrowing Capacity That May Be Elected After Effective Loan Date Maximum loan increase that may be requested Line of Credit Facility, Basis Points of Facility Fees Facility fee basis points Facility Fee Basis Points Debt Instrument, Extension Fee Amount Debt Instrument, Extension Fee Amount Extension fee amount Gain (Loss) on Early Termination of Debt Gain (Loss) on Early Termination of Debt Gain on early termination Debt Instrument, Credit Rating Unsecured Debt Ratings Debt Instrument [Axis] Debt Instrument Name [Domain] Debt Instrument, Name [Domain] Revolving Credit Facility and Other Variable Rate Mortgage Debt [Member] Revolving Credit Facility And Other Variable Rate Mortgage Debt [Member] Revolving Credit Facility Borrowing And Other Variable Rate Mortgage Debt [Member] Fixed Rate Debt and Other Obligations [Member] Fixed Rate Debt And Other Obligations [Member] Fixed Rate Debt And Other Obligations [Member] Number Of Properties With Encumbered Company Mortgages Number Of Properties With Encumbered Company Mortgages Number of properties with encumbered company mortgages Carrying Value of the Mortgaged Property Mortgage Property, Carrying Value Carrying value of encumbered properties Interest Paid Cash paid for interest Interest Costs, Capitalized During Period Interest capitalized Long-term Debt, Weighted Average Interest Rate Total indebtedness, weighted average interest rate Port Imperial Four Five Hotel [Member] Port Imperial Four Five Hotel [Member] Port Imperial 4/5 Hotel [Member] Secured Debt, Name of the Property Secured Debt, Name of the Property Property Name Secured Debt, Lending Institution Secured Debt, Lending Institution Lender Debt, Loans Payable, And Other Obligations, Net Debt, Loans Payable, And Other Obligations, Net Total mortgages, loans payable and other obligations, net Debt Instrument, Interest Rate, Effective Percentage After Five Years Debt Instrument, Interest Rate, Effective Percentage After Five Years Effective percentage after five years Debt Instrument, Term At Fixed Rate Debt Instrument, Term At Fixed Rate First period of term period Schedule of Deferred Compensation Arrangement with Individual, Postretirement Benefits [Table] Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items] Savings Retirement Plan Employee Minimum Subscription Rate Savings Retirement Plan Employee Minimum Subscription Rate Minimum employee subscription rate, percentage of compensation Savings Retirement Plan Employee Maximum Subscription Rate Savings Retirement Plan Employee Maximum Subscription Rate Maximum employee subscription rate, percentage of compensation Employee pre-tax contributions vested percent. Employee Pre Tax Contributions Vested Percent Employee pre-tax contributions vested percentage Savings Retirement Plan Vesting Period Savings Retirement Plan Vesting Period Employer contribution vesting period Vesting rate Vesting Rate Vesting rate Percent vested after total service period. Percent Vested After Total Service Period Percentage vested after total service period Savings Retirement Plan Vesting Rights Savings Retirement Plan Vesting Rights Employees' vesting rights Employee Benefits and Share-based Compensation Expenses for employee benefit plan Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Debt Instrument, Fair Value Fair value of Company's long-term debt Harborside Financial Center Plaza 4-A [Member] Harborside Financial Center Plaza Foura [Member] Harborside Plaza 4-A [Member] Harborside Financial Center Plaza 5 [Member] Harborside Financial Center Plaza Five [Member] Harborside Plaza 5 [Member] Port Imperial South One Third Garage Development [Member] Port Imperial South One Third Garage Development [Member] Port Imperial South 1/3 Garage [Member] Project Term Project Term Project period Payments in Lieu of Property Tax As Percentage of Total Project Cost Payments in Lieu of Property Tax As Percentage of Total Project Cost Percentage of PILOT on project costs Estimated Cost Of Project Estimated Cost Of Project Total project costs Payments In Lieu Of Property Taxes Payments In Lieu Of Property Taxes Payments in lieu of property taxes (PILOT) Payments In Lieu Of Property Taxes, Annual Payment Payments In Lieu Of Property Taxes, Annual Payment Annual Payments in lieu of property taxes (PILOT) Payments In Lieu Of Property Tax As Percentage Based On The Land Value Payments In Lieu Of Property Tax As Percentage Based On Land Value Percentage of taxes paid based on the land value Annual Percentage Of Cost For Phase In Annual Percentage Of Cost For Phase In Annual percentage of cost for phase in Payments In Lieu Of Property Tax As Percentage Of Gross Revenues Payments In Lieu Of Property Tax As Percentage Of Gross Revenues Percentage of PILOT on gross revenues Lessee, Lease, Description [Table] Lessee, Lease, Description [Line Items] Operating Lease, Expense, Including Sublease Rentals Operating Lease, Expense, Including Sublease Rentals Ground lease expense incurred Operating Lease, Liability Operating lease Total Operating Lease, Number of Units Operating Lease, Number of Units Number of ground leases Lessee, Finance Lease, Term of Contract Term of lease contract Lessee, Operating Lease, Discount Rate Borrowing rate Property Net Book Value Property Net Book Value Properties aggregate net book value Delivery date of constructed building Delivery Date Of Constructed Building Delivery date to tenant Amount To Fund Amount To Fund Amount to fund Changes In Executive Officers [Table] Changes In Executive Officers [Table] Changes In Executive Officers [Line Items] Changes In Executive Officers [Line Items] Annual Base Salary Annual Base Salary Annual base salary Annual Bonus Opportunity Percentage Annual Bonus Opportunity Percentage Annual bonus opportunity percentage Annual Bonus Opportunity Threshold Percentage Annual Bonus Opportunity Threshold Percentage Annual bonus opportunity threshold percentage Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Shares Under Options - Granted Shares granted Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Exercisable period Expiration period Period For Continuation Of Health Insurance Period For Continuation Of Health Insurance Period for continuation of health insurance Property Lock-Ups Expired [Member] Property Lock Ups Expired [Member] Property Lock-Ups Expired [Member] Operating Leases, Future Minimum Payments Due, Current 2019 Operating Leases, Future Minimum Payments, Remainder of Fiscal Year July 1 through December 31, 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 Operating Leases, Future Minimum Payments, Due Thereafter 2024 through 2098 Operating Leases, Future Minimum Payments Due Total Operating Leases, Future Minimum Payments, Undiscounted Excess Amount Operating Leases, Future Minimum Payments, Undiscounted Excess Amount Less: imputed interest Property Subject to or Available for Operating Lease, by Major Property Class [Table] Property Subject to or Available for Operating Lease [Axis] Property Subject To Or Available For Operating Lease [Domain] Property Subject to or Available for Operating Lease [Domain] Tenant Leases [Member] Tenant Leases [Member] Tenant Leases [Member] Property Subject to or Available for Operating Lease [Line Items] Operating Leases, Future Minimum Payments Receivable, Current 2019 Operating Leases, Future Minimum Payments Receivable, Remainder of Fiscal Year 2019 Operating Leases, Future Minimum Payments Receivable, in Two Years 2020 Operating Leases, Future Minimum Payments Receivable, in Three Years 2021 Operating Leases, Future Minimum Payments Receivable, in Four Years 2022 Operating Leases, Future Minimum Payments Receivable, in Five Years 2023 Operating Leases, Future Minimum Payments Receivable, Thereafter 2024 and thereafter Operating Leases, Future Minimum Payments Receivable Total Lease Expiration Date Operating leases with various expiration dates through year Lease Period Lease Period Lease period Preferred Units, Contribution To Obtain Equity Units Preferred Units, Contribution To Obtain Equity Units Contributed amount to obtain equity units Annual Return From Cash Flow Operations Annual Return From Cash Flow Operations Annual return Annual Return On The Equity Value Annual Return On The Equity Value Annual return on the equity value Annual Return On The Equity Value, Base Return Annual Return On The Equity Value, Base Return Base return Annual Return On The Equity Value, Capital Base Return Annual Return On The Equity Value, Capital Base Return Capital base return Pro Rata Distribution Percent Pro Rata Distribution Percent Pro rata distribution Pro Rata Distribution Percent, Cash Flow From Capital Events Pro Rata Distribution Percent, Cash Flow From Capital Events Pro rata share Value of the preferred units acquired. Preferred Unit Value Preferred unit in operating partnership Convertible Preferred Unit, Shares Issued Upon Conversion Convertible Preferred Unit, Shares Issued Upon Conversion Convertible preferred units Conversion Of Stock, Number Of Shares Called By Stocks Conversion Of Stock, Number Of Shares Called By Stocks Shares that may be converted to common units Common Unit Distributions Per Unit Declared Common Unit Distributions Per Unit Declared Common unit distribution per unit declared Distribution declared per common unit Invested Capital Invested Capital Invested capital Preferred Units, Purchase Price Preferred Units, Purchase Price Purchase price Preferred Units, Purchase Price, Less Distribution Preferred Units, Purchase Price, Less Distribution Purchase price, less distributions Loan-To-Value Ratio Loan-To-Value Ratio Loan-to-value ratio Line of Credit Facility, Increased Borrowing Capacity Line of Credit Facility, Increased Borrowing Capacity Increased line of credit Equity Capitalization Excess Percent Equity Capitalization Excess Percent Equity capitalization percent Temporary Equity, Stock Issued During Period, Value, Gross Temporary Equity, Stock Issued During Period, Value, Gross Redeemable Noncontrolling Interests Issued (net of new issuance costs of $1.5 million) Temporary Equity, Stock Issued During Period, Value, New Issues Net Redeemable Noncontrolling Interest Decrease From Distribution Redeemable Noncontrolling Interest Decrease From Distribution Distributions Redeemable Noncontrolling Interest Issuance Costs Redeemable Noncontrolling Interest Issuance Costs Issuance Costs Date Share Repurchase Program was initiated. Date Share Repurchase Program Initiation Date share repurchase program was initiated Stock Repurchase Program Authorized Amount Capacity of share repurchase program Stock Repurchased and Retired During Period, Shares Shares purchased and retired Payments for Repurchase of Equity Aggregate cost of stock repurchased Stock Repurchase Program Remaining Authorized Repurchase Amount Capacity available for additional repurchase of outstanding common stock Proceeds from Issuance of Common Limited Partners Units Proceeds from sale of common units Common stock reserved for future issuance Reserved stocks for issuance Monthly cash investment without restriction, maximum. Monthly Cash Investment Without Restriction Maximum Monthly cash investment without restriction, maximum Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2013 Incentive Stock Plan [Member] Two Thousand Thirteen Incentive Stock Plan [Member] 2013 Incentive Stock Plan [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Stock compensation vesting period Exercisable time period Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term Weighted average remaining contractual life Share price Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Options exercised Stock or Unit Option Plan Expense Stock options expense Share Based Compensation Arrangement By Share-based Payment Award Threshold Share Price Trigger Share Based Compensation Arrangement By Share-based Payment Award Threshold Share Price Trigger Common stock trade share price Share Based Compensation Arrangement By Share-based Payment Award Vesting Installment Term Share Based Compensation Arrangement By Share-based Payment Award Vesting Installment Term Annual installments Share Based Compensation Arrangement By Share-based Payment Award Threshold Trading Days Share Based Compensation Arrangement By Share-based Payment Award Threshold Trading Days Common stock trading days Share-based Compensation Arrangement by Share-based Payment Award, Options, Shares To Be Vested and Expected to Vest, Exercisable, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Shares To Be Vested and Expected to Vest, Exercisable, Number Shares to be vested and exercisable Income Allocation Equivalent, Percent Income Allocation Equivalent, Percent Income allocation Share-based Compensation Arrangement by Share-based Payment Award, Expiration Date Common stock expiration date Cash Distribution, Percent Cash Distribution, Percent Percent of cash distribution Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Share price - weighted average fair value of options granted Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized Total unrecognized compensation cost Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition Total unrecognized compensation cost, period of recognition Award Type [Axis] Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Award Type [Domain] Restricted Stock [Member] Restricted Stock [Member] Total Stockholder Return Based Awards [Member] Total Stockholder Return Based Awards [Member] Total Stockholder Return Based Awards [Member] Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Unvested In Period Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Unvested In Period Unvested performance shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Shares, Outstanding, Ending balance Shares, Outstanding, Beginning balance Unvested stock outstanding Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Shares, Granted Shares granted Percentage Of Shares Vested Percentage Of Shares Vested Percentage of shares vested Share Based Compensation Arrangement By Share-based Payment Award Performance Period Share Based Compensation Arrangement By Share-based Payment Award Performance Period Performance period Percentage Of Award Percentage Of Award Percent of the award Remaining Percentage Of The Award Remaining Percentage Of The Award Remaining percent of the award Total Stockholder Return, Percent Total Stockholder Return, Percent TSR percent Common Stock Dividends Per Share Paid Percent, Payable On Common Unit Common Stock Dividends Per Share Paid Percent, Payable On Common Unit Dividends paid, percent representing common unit of limited partnership interest Common Stock Dividends Per Share Paid Percent, Payable Upon Vesting Of Long-Term Investment Plan Unit Common Stock Dividends Per Share Paid Percent, Payable Upon Vesting Of Long-Term Investment Plan Unit Dividends paid, percent payable upon vesting of LTIP Unit Maximum Percentage Of Retainer Fee Directors May Elect To Defer To Stock Units Maximum Percentage Of Retainer Fee Directors May Elect To Defer To Stock Units Maximum percentage of retainer fee that directors may defer Deferred stock units earned. Deferred Stock Units Shares Earned Deferred stock units earned Deferred Stock Units, Converted Deferred Stock Units, Converted Deferred stock units converted Deferred stock units outstanding. Deferred Stock Units Outstanding Deferred stock units outstanding Unvested Restricted Stock [Member] Unvested Restricted Stock [Member] Unvested Restricted Stock [Member] Unvested Long-Term Incentive Plan Awards [Member] Unvested Long Term Incentive Plan Awards [Member] Unvested LTIP Units [Member] Unvested AO Long-Term Incentive Plan Awards [Member] Unvested Ao Long Term Incentive Plan Awards [Member] Unvested AO LTIP Units [Member] Dividends declared per common share Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest Net income Net income (loss) Noncontrolling Interest, Redemption Value Adjustment, Redeemable Noncontrolling Interest, Redemption Value Adjustment, Redeemable Add (deduct): Redeemable noncontrolling interests Redeemable noncontrolling interests Minority Interest, Decrease From Noncontrolling Interest Minority Interest, Decrease From Noncontrolling Interest Change in noncontrolling interests in consolidated joint ventures Stock Based Compensation Attributable To Noncontrolling Interest Stock Based Compensation Attributable To Noncontrolling Interest Stock compensation Stock Issued During Period, Value, Restricted Shares, Forfeited Stock Issued During Period, Value, Restricted Shares, Forfeited Cancellation of restricted shares Stock Issued During Period, Value, Long-Term Incentive Plan Units, Forfeited Stock Issued During Period, Value, Long-Term Incentive Plan Units, Forfeited Cancellation of unvested LTIP units Share-based Payment Arrangement, Option, Exercise Price Range [Table] Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options Shares Under Options - 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Common Units Add: Operating Partnership - common and vested LTIP units Restricted Stock Awards, shares. 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