Document and Entity Information [Abstract] Document and Entity Information Statement [Table] Statement [Line Items] Entity Registrant Name Document Type Amendment Flag Document Period End Date Entity Central Index Key Current Fiscal Year End Date Entity Filer Category Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Statement of Financial Position ASSETS Land and leasehold interests Buildings and improvements Investment Building and Building Improvements, Total Tenant improvements Furniture, fixtures and equipment Furniture, fixtures and equipment Gross investment in rental property Gross investment in rental property Less - accumulated depreciation and amortization Less - accumulated depreciation and amortization Less - accumulated depreciation and amortization Less - accumulated depreciation and amortization Net investment in rental property Net investment in rental property Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Cash and cash equivalents, beginning of period Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value, Total Investments In Affiliates Subsidiaries Associates And Joint Ventures Investments in unconsolidated joint ventures Investment in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Total Unbilled rents receivable, net Deferred charges and other assets, net Other Assets, Total Restricted cash Accounts Receivable Net Accounts receivable, net of allowance for doubtful accounts of $2,293 and $2,036 Accounts receivable, net of allowance for doubtful accounts of $2,905 and $2,319 Total assets Total assets LIABILITIES AND EQUITY Unsecured Debt Senior unsecured notes Unsecured Debt, Total Secured Debt Mortgages, loans payable and other obligations Secured Debt, Total Dividends and distributions payable Accounts payable, accrued expenses and other liabilities Accounts Payable and Accrued Liabilities, Total 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 Accrued interest payable Total liabilities Total liabilities Commitments And Contingencies 2009 Commitments and contingencies Equity: Preferred stock, $0.01 par value, 5,000,000 shares authorized, 10,000 and 10,000 shares outstanding, at liquidation preference Preferred Stock, Value, Issued, Ending Balance Preferred Stock, Value, Issued, Beginning Balance Preferred Stock, Value, Issued, Total Common stock, $0.01 par value, 190,000,000 shares authorized, 79,528,151 and 78,969,752 shares outstanding Common stock, $0.01 par value, 190,000,000 shares authorized, 79,398,646 and 78,969,752 shares outstanding Common stock, $0.01 par value, 190,000,000 shares authorized, 79,398,646 and 78,969,752 shares outstanding Common stock, $0.01 par value, 190,000,000 shares authorized, 79,398,646 and 78,969,752 shares outstanding Common stock, $0.01 par value, 190,000,000 shares authorized, 79,398,646 and 78,969,752 shares outstanding Additional Paid In Capital Additional Paid in Capital, Ending Balance Additional Paid in Capital, Beginning Balance Additional paid-in capital Additional Paid in Capital, Total Retained Earnings Accumulated Deficit Retained Earnings (Accumulated Deficit), Ending Balance Retained Earnings (Accumulated Deficit), Beginning Balance Dividends in excess of net earnings Dividends in excess of net earnings Stockholders' Equity Attributable to Parent Stockholders' Equity Attributable to Parent, Ending Balance Stockholders' Equity Attributable to Parent, Beginning Balance Total Mack-Cali Realty Corporation stockholders' equity Noncontrolling Interest Items [Abstract] Noncontrolling interests in subsidiaries: Operating Partnership Minority Interest In Joint Ventures Consolidated joint ventures Consolidated joint ventures Noncontrolling interests in consolidated joint ventures Total noncontrolling interests in subsidiaries Stockholders' Equity Attributable to Noncontrolling Interest, Ending Balance Stockholders' Equity Attributable to Noncontrolling Interest, Beginning Balance Total noncontrolling interests in subsidiaries Total equity Balance, value Balance, value Total equity Liabilities And Stockholders Equity Total liabilities and equity Total liabilities and equity Statement Of Financial Position (Parenthetical) [Abstract] Statement Of Financial Position (Parenthetical) Allowance for doubtful accounts receivable Preferred stock, par or stated value per share Preferred stock, par value per share Preferred stock, shares authorized Preferred stock, shares outstanding Preferred Stock, Shares Outstanding, Ending Balance Preferred Stock, Shares Outstanding, Beginning Balance Common stock, par value per share Common stock, shares authorized Common Stock Shares Outstanding Common Stock, Shares, Outstanding, Ending Balance Common Stock, Shares, Outstanding, Beginning Balance Common stock, shares outstanding Income Statement REVENUES Base rents Operating Leases, Income Statement, Lease Revenue, Total Escalations and recoveries from tenants Construction services Other Real Estate Revenue Real estate services Other income Other income Real Estate Revenue, Net Total revenues EXPENSES Real estate taxes Utilities Operating services Operating Costs and Expenses, Total Direct construction costs General and administrative General and Administrative Expense, Total Depreciation and amortization Depreciation and amortization Costs and Expenses Total expenses Operating income Operating income OTHER (EXPENSE) INCOME Interest expense Interest expense Interest Expense, Total Interest and other investment income Investment Income, Interest and Dividend, Total Equity in earnings (loss) of unconsolidated joint ventures Equity in (earnings) loss of unconsolidated joint venture, net Equity in (earnings) loss of unconsolidated joint ventures Income (Loss) from Equity Method Investments, Total Gain on reduction of other obligations Gain on reduction of other obligations Gains (Losses) on Extinguishment of Debt, Total Nonoperating Income (Expense) Total other (expense) income Income from continuing operations Income from continuing operations Discontinued Operations Discontinued Operations Discontinued Operations: Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax Income from discontinued operations Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax, Total Gain (Loss) on Disposition of Assets Realized gains (losses) and unrealized losses on disposition of rental property, net Gain (Loss) on Disposition of Assets, Total Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Total discontinued operations, net Total discontinued operations, net Net income Net income Noncontrolling interest in consolidated joint ventures Noncontrolling interest in consolidated joint ventures Noncontrolling interest in Operating Partnership Noncontrolling interest in Operating Partnership Amount of net income (loss) for the period allocated to noncontrolling partners in discontinued operations included in the entity's consolidated financial statements. Noncontrolling Interest In Discontinue Operations Noncontrolling interest in discontinued operations Noncontrolling Interest In discontinued operations Preferred Stock Dividends Preferred stock dividends Preferred stock dividends Preferred stock dividends Net Income Loss Net income available to common shareholders Net income available to common shareholders Basic earnings per common share: Income Loss From Continuing Operations Per Basic Share Income from continuing operations Income from continuing operations available to common shareholders Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share Discontinued operations Discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Per Outstanding Share, Total Net income available to common shareholders Net income available to common shareholders Net income available to common shareholders Diluted earnings per common share: Income Loss From Continuing Operations Per Diluted Share Income from continuing operations Income from continuing operations available to common shareholders Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share Discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share, Total Earnings Per Share Diluted Net income available to common unitholders Net income available to common shareholders Basic weighted average shares outstanding Basic weighted average shares outstanding Diluted weighted average shares outstanding Diluted weighted average shares outstanding Statement of Stockholders' Equity Shares, Issued Balance, shares Balance, shares Dividends Preferred Stock Preferred stock dividends Preferred stock dividends Dividends, Preferred Stock, Total Common stock dividends Common stock dividends Dividends, Common Stock, Total Common unit distributions Increase in noncontrolling interest Increase in noncontrolling interests Redemption of common units for common stock, value Redemption of common units for common stock, par value Redemption of common units for common stock, shares Shares issued under Dividend Reinvestment and Stock Purchase Plan, value Shares issued under Dividend Reinvestment and Stock Purchase Plan, shares Stock options exercised, value Stock options exercised, shares Stock Compensation, value Stock compensation, value Stock Compensation, shares Stock compensation, shares Rebalancing of ownership percent between parent and subsidiaries Statement, Equity Components [Axis] Equity Component [Domain] Parent [Member] Preferred Stock Common Stock Additional Paid-in Capital Dividends in Excess of Net Earnings Noncontrolling Interests in Subsidiaries [Member] Statement of Cash Flows CASH FLOWS FROM OPERATING ACTIVITIES Adjustments to reconcile net income to net cash provided by Operating activities: Depreciation and amortization, including related intangibles assets Depreciation, Depletion and Amortization, Total Depreciation Amortization On Discontinued Operations Depreciation Amortization On Discontinued Operations Depreciation and amortization on discontinued operations Stock compensation Amortization of stock compensation Amortization of stock compensation Amortization of deferred financing costs and debt discount Amortization of Financing Costs and Discounts, Total Gain (Loss) on Disposition of Property Realized gains on disposition of rental property Realized gains on disposition of rental property Gain (Loss) on Disposition of Property, Total Equity Method Investment Dividends Or Distributions Distributions of cumulative earnings from unconsolidated joint ventures Distributions of cumulative earnings from unconsolidated joint ventures Changes in operating assets and liabilities: Increase in unbilled rents receivable, net Increase in unbilled rents receivable, net Increase in deferred charges and other assets, net Increase in deferred charges and other assets, net (Increase) decrease in deferred charges and other assets, net (Increase) decrease in accounts receivable, net (Increase) decrease in accounts receivable, net Increase (decrease) in accounts payable, accrued expenses and other liabilities Increase (decrease) in accounts payable, accrued expenses and other liabilities Increase in accounts payable, accrued expenses and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities, Total 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) increase 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 Decrease in accrued interest payable Net cash provided by operating activities Net cash provided by operating activities CASH FLOWS FROM INVESTING ACTIVITIES Additions to rental property and related intangibles Additions to rental property and related intangibles Additions to rental property and related intangibles Additions to rental property and related intangibles 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 Increase Decrease In Restricted Cash Decrease (increase) in restricted cash (Increase) decrease in restricted cash (Increase) decrease in restricted cash (Increase) decrease in restricted cash Net cash used in investing activities Net cash used in investing activities CASH FLOWS FROM FINANCING ACTIVITIES Borrowings from revolving credit facility Borrowings from revolving credit facility Repayment of revolving credit facility and money market loans Repayment of revolving credit facility and money market loans Proceeds from senior unsecured notes Repayments of senior unsecured notes Repayments of senior unsecured notes Proceeds from mortgages and loans payable Proceeds from mortgages Repayment of mortgages, loans payable and other obligations Repayment of mortgages, loans payable and other obligations Payment of financing costs Payment of financing costs Payments of Financing Costs, Total Proceeds from offering of Common Stock Proceeds from stock options exercised Payment of dividends and distributions Payment of dividends and distributions Payment of dividends and distributions Payment of dividends and distributions Net cash provided used in financing activities Net cash (used in) provided for financing activities Net (decrease) increase in cash and cash equivalents Net (decrease) increase in cash and cash equivalents Organization and Basis of Presentation [Abstract] Organization and Basis of Presentation Organization Consolidation And Presentation Of Financial Statements Disclosure TextBlock ORGANIZATION AND BASIS OF PRESENTATION Significant Accounting Policies [Abstract] Significant Accounting Policies Significant Accounting Policies Textblock SIGNIFICANT ACCOUNTING POLICIES Real Estate Transaction Real Estate Transaction Real Estate Transactions Textblock Real Estate Transaction REAL ESTATE TRANSACTION Investments in Unconsolidated Joint Ventures [Abstract] Investments in Unconsolidated Joint Ventures Equity Method Investments Disclosure TextBlock INVESTMENTS IN UNCONSOLIDATED JOINT VENTURES Deferred Charges and Other Assets [Abstract] Deferred Charges and Other Assets Deferred Costs Capitalized Prepaid And Other Assets Disclosure TextBlock DEFERRED CHARGES AND OTHER ASSETS Discontinued Operations Policy TextBlock Discontinued Operations DISCONTINUED OPERATIONS Senior Unsecured Notes Senior Unsecured Notes Description of an entity's senior unsecured notes Senior Unsecured Notes [Text Block] Senior Unsecured Notes SENIOR UNSECURED NOTES Unsecured Revolving Credit Facility [Abstract] Unsecured Revolving Credit Facility Schedule Of Line Of Credit Facilities TextBlock UNSECURED REVOLVING CREDIT FACILITY Mortgages, Loans Payable and Other Obligations [Abstract] Mortgages, Loans Payable and Other Obligations Description of an entity's mortgages, loans payable and other obligations Mortgages And Notes Payable [Text Block] Mortgages, Loans Payable and Other Obligations MORTGAGES, LOANS PAYABLE AND OTHER OBLIGATIONS Employee Benefit 401k Plans [Abstract] Employee Benefit 401k Plans Pension And Other Postretirement Benefits Disclosure TextBlock Employee Benefit 401(k) plans EMPLOYEE BENEFIT 401(k) PLANS Disclosure of Fair Value of Financial Instruments [Abstract] Disclosure of Fair Value of Financial Instruments Fair Value Disclosures TextBlock DISCLOSURE OF FAIR VALUE OF FINANCIAL INSTRUMENTS Commitments and Contingencies [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure Textblock COMMITMENTS AND CONTINGENCIES Tenant Leases [Abstract] Tenant Leases Leases Of Lessor Disclosure TextBlock TENANT LEASES Mack-Cali Realty Corporation Stockholders' Equity Stockholders Equity Note Disclosure TextBlock MACK-CALI REALTY CORPORATION STOCKHOLDER'S EQUITY Noncontrolling Interests in Subsidiaries [Abstract] Noncontrolling Interests in Subsidiaries Minority Interest Disclosure TextBlock Noncontrolling Interests in Subsidiaries NONCONTROLLING INTERESTS IN SUBSIDIARIES Segment Reporting [Abstract] Segment Reporting Segment Reporting Disclosure Textblock SEGMENT REPORTING Impact of Recently-Issued Accounting Standards Schedule Of New Accounting Pronouncements And Changes In Accounting Principles TextBlock IMPACT OF RECENTLY-ISSUED ACCOUNTING STANDARDS