Veris Residential (VRE) 10-Q 23 Apr 15 2015 Q1 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 20, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	MACK CALI REALTY CORP
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Entity Central Index Key	924901
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Entity Common Stock, Shares Outstanding		89,128,711

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
Rental property
Land and leasehold interests	$760,628,000	$760,855,000
Buildings and improvements	3,769,787,000	3,753,300,000
Tenant improvements	412,351,000	431,969,000
Furniture, fixtures and equipment	12,527,000	12,055,000
Gross investment in rental property	4,955,293,000	4,958,179,000
Less - accumulated depreciation and amortization	-1,417,335,000	-1,414,305,000
Net investment in rental property	3,537,958,000	3,543,874,000
Cash and cash equivalents	19,315,000	29,549,000
Investments in unconsolidated joint ventures	262,052,000	247,468,000
Unbilled rents receivable, net	123,547,000	123,885,000
Deferred charges, goodwill and other assets, net	210,760,000	204,650,000
Restricted cash	35,780,000	34,245,000
Accounts receivable, net of allowance for doubtful accounts of $1,513 and $2,584	9,442,000	8,576,000
Total assets	4,198,854,000	4,192,247,000
LIABILITIES AND EQUITY
Senior unsecured notes	1,268,018,000	1,267,744,000
Revolving credit facility	42,000,000	0
Mortgages, loans payable and other obligations	797,554,000	820,910,000
Dividends and distributions payable	15,560,000	15,528,000
Accounts payable, accrued expenses and other liabilities	134,462,000	126,971,000
Rents received in advance and security deposits	47,429,000	52,146,000
Accrued interest payable	29,608,000	26,937,000
Total liabilities	2,334,631,000	2,310,236,000
Commitments and contingencies
Mack-Cali Realty Corporation stockholders' equity:
Common stock, $0.01 par value, 190,000,000 shares authorized 89,127,942 and 89,076,578 shares outstanding	891,000	891,000
Additional paid-in capital	2,561,463,000	2,560,183,000
Dividends in excess of net earnings	-952,183,000	-936,293,000
Total Mack-Cali Realty Corporation stockholders' equity	1,610,171,000	1,624,781,000
Noncontrolling interests in subsidiaries:
Operating Partnership	199,391,000	202,173,000
Consolidated joint ventures	54,661,000	55,057,000
Total noncontrolling interests in subsidiaries	254,052,000	257,230,000
Total equity	1,864,223,000	1,882,011,000
Total liabilities and equity	$4,198,854,000	$4,192,247,000

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts receivable	$1,513	$2,584
Common stock, par value per share	$0.01	$0.01
Common stock, shares authorized	190,000,000	190,000,000
Common stock, shares outstanding	89,127,942	89,076,578

Consolidated_Statements_Of_Ope

Consolidated Statements Of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
REVENUES
Base rents	$123,793	$134,051
Escalations and recoveries from tenants	18,399	25,568
Real estate services	7,644	6,692
Parking income	2,542	2,114
Other income	1,337	1,171
Total revenues	153,715	169,596
EXPENSES
Real estate taxes	22,452	24,351
Utilities	17,575	28,281
Operating services	28,228	29,222
Real estate services expenses	6,639	6,709
General and administrative	11,011	22,881
Depreciation and amortization	40,802	44,985
Total expenses	126,707	156,429
Operating income	27,008	13,167
OTHER (EXPENSE) INCOME
Interest expense	-27,215	-29,946
Interest and other investment income	267	386
Equity in earnings (loss) of unconsolidated joint ventures	-3,529	-1,235
Realized gains (losses) on disposition of rental property, net	144
Total other (expense) income	-30,333	-30,795
Net loss	-3,325	-17,628
Noncontrolling interest in consolidated joint ventures	490	322
Noncontrolling interest in Operating Partnership	314	2,008
Net loss available to common shareholders	($2,521)	($15,298)
Basic earnings per common share:
Net loss available to common shareholders	($0.03)	($0.17)
Diluted earnings per common share:
Net loss available to common unitholders	($0.03)	($0.17)
Basic weighted average shares outstanding	89,192	88,289
Diluted weighted average shares outstanding	100,266	99,876

Consolidated_Statement_Of_Chan

Consolidated Statement Of Changes In Equity (USD $)	Common Stock [Member]	Additional Paid-In Capital [Member]	Dividends In Excess Of Net Earnings [Member]	Noncontrolling Interests In Subsidiaries [Member]	Total
In Thousands
Balance, value at Dec. 31, 2013				$276,096
Net loss				-2,330	-17,628
Common unit distributions				-3,455
Redemption of common units for common stock, value				-6,452
Rebalancing of ownership percentage between parent and subsidiaries				-21
Balance, value at Mar. 31, 2014				263,838
Balance, value at Dec. 31, 2014	891	2,560,183	-936,293	257,230	1,882,011
Balance, shares at Dec. 31, 2014	89,077
Net loss			-2,521	-804	-3,325
Common stock dividends			-13,369		-13,369
Common unit distributions				-1,656	-1,656
Increase in noncontrolling interest in consolidated joint ventures				94	94
Redemption of common units for common stock, value		857		-857
Redemption of common units for common stock, shares	47
Shares issued under Dividend Reinvestment and Stock Purchase Plan, value		12			12
Directors' deferred compensation plan, value		98			98
Stock compensation, value		358			358
Stock compensation, shares	4
Rebalancing of ownership percentage between parent and subsidiaries		-45		45
Balance, value at Mar. 31, 2015	$891	$2,561,463	($952,183)	$254,052	$1,864,223
Balance, shares at Mar. 31, 2015	89,128

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	($3,325)	($17,628)
Adjustments to reconcile net income to net cash provided by Operating activities:
Depreciation and amortization, including related intangible assets	41,185	45,461
Amortization of deferred stock units	98	117
Amortization of stock compensation	313	4,543
Amortization of deferred financing costs	953	769
Amortization of debt discount and mark-to-market	997	1,889
Equity in (earnings) loss of unconsolidated joint venture, net	3,529	1,235
Distributions of cumulative earnings from unconsolidated joint ventures	815	1,811
Realized (gains) loss on disposition of rental property, net	-144
Changes in operating assets and liabilities:
Decrease (increase) in unbilled rents receivable, net	347	-2,908
Increase in deferred charges, goodwill and other assets	-10,828	-17,634
Increase in accounts receivable, net	-866	-2,316
Increase in accounts payable, accrued expenses and other liabilities	8,159	21,579
Decrease in rents received in advance and security deposits	-4,717	-3,554
Increase (decrease) in accrued interest payable	2,671	-5,894
Net cash provided by operating activities	39,187	27,470
CASH FLOWS FROM INVESTING ACTIVITIES
Rental property additions and improvements	-19,658	-14,600
Development of rental property, other related costs and deposits	-12,519	-7,357
Proceeds from the sale of rental property	1,072
Investment in unconsolidated joint ventures	-20,880	-1,889
Distributions in excess of cumulative earnings from unconsolidated joint ventures	1,097	456
Increase in restricted cash	-1,535	-826
Net cash used in investing activities	-52,423	-24,216
CASH FLOW FROM FINANCING ACTIVITIES
Borrowings from revolving credit facility	56,000	70,000
Repayment of revolving credit facility	-14,000
Repayment of senior unsecured notes		-200,000
Proceeds from mortgages and loans payable	1,150	425
Repayment of mortgages, loans payable and other obligations	-25,228	-2,793
Payment of contingent consideration		-3,936
Payment of financing costs	-30
Cash from noncontrolling interests	94
Payment of dividends and distributions	-14,984	-29,922
Net cash provided by (used in) financing activities	3,002	-166,226
Net decrease in cash and cash equivalents	-10,234	-162,972
Cash and cash equivalents, beginning of period	29,549	221,706
Cash and cash equivalents, end of period	$19,315	$58,734

Organization_And_Basis_Of_Pres

Organization And Basis Of Presentation	3 Months Ended
	Mar. 31, 2015
Organization And Basis Of Presentation [Abstract]
Organization And Basis Of Presentation	1.    ORGANIZATION AND BASIS OF PRESENTATION
	Organization
	Mack-Cali Realty Corporation, a Maryland corporation, together with its subsidiaries (collectively, the “Company”), is a fully-integrated, self-administered, self-managed real estate investment trust (“REIT”) providing leasing, management, acquisition, development, construction and tenant-related services for its properties and third parties.  As of March 31, 2015, the Company owned or had interests in 283 properties, consisting of 263 commercial properties, primarily class A office and office/flex properties, totaling approximately 30.9 million square feet, leased to approximately 2,000 commercial tenants, and 20 multi-family rental properties containing 5,861 residential units, plus developable land (collectively, the “Properties”).  The Properties are comprised of 248 buildings, primarily office and office/flex buildings totaling approximately 30.4 million square feet (which include 36 buildings, primarily office buildings aggregating approximately 5.6 million square feet owned by unconsolidated joint ventures in which the Company has investment interests), six industrial/warehouse buildings totaling approximately 387,400 square feet, 20 multi-family properties totaling 5,861 apartments (which include 14 properties aggregating 4,560 apartments owned by unconsolidated joint ventures in which the Company has investment interests), five parking/retail properties totaling approximately 121,500 square feet (which include two buildings aggregating 81,500 square feet owned by unconsolidated joint ventures in which the Company has investment interests), one hotel (which is owned by an unconsolidated joint venture in which the Company has an investment interest) and three parcels of land leased to others.  The Properties are located in seven states, primarily in the Northeast, plus the District of Columbia.
	BASIS OF PRESENTATION
	The accompanying consolidated financial statements include all accounts of the Company, its majority-owned and/or controlled subsidiaries, which consist principally of Mack-Cali Realty, L.P. (the “Operating Partnership”), and variable interest entities for which the Company has determined itself to be the primary beneficiary, if any.  See Note 2: Significant Accounting Policies – Investments in Unconsolidated Joint Ventures, for the Company’s treatment of unconsolidated joint venture interests.  Intercompany accounts and transactions have been eliminated.
	Accounting Standards Codification (“ASC”) 810, Consolidation, provides guidance on the identification of entities for which control is achieved through means other than voting rights (“variable interest entities” or “VIEs”) and the determination of which business enterprise, if any, should consolidate the VIEs. Generally, the consideration of whether an entity is a VIE applies when either: (1) the equity investors (if any) lack one or more of the essential characteristics of a controlling financial interest; (2) the equity investment at risk is insufficient to finance that entity’s activities without additional subordinated financial support; or (3) the equity investors have voting rights that are not proportionate to their economic interests and the activities of the entity involve or are conducted on behalf of an investor with a disproportionately small voting interest.  The Company consolidates VIEs in which it is considered to be the primary beneficiary.  The primary beneficiary is defined by the entity having both of the following characteristics: (1) the power to direct the activities that, when taken together, most significantly impact the variable interest entity’s performance: and (2) the obligation to absorb losses and right to receive the returns from the VIE that would be significant to the VIE.
	As of March 31, 2015 and December 31, 2014, the Company’s investments in consolidated real estate joint ventures in which the Company is deemed to be the primary beneficiary have total real estate assets of $253.5 million and $242.9 million, respectively, mortgages of $98.3 million and $94.3 million, respectively, and other liabilities of $20.5 million and $15.7 million, respectively.
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period.  Actual results could differ from those estimates.  Certain reclassifications have been made to prior period amounts in order to conform with current period presentation.

Significant_Accounting_Policie

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Significant Accounting Policies [Abstract]
Significant Accounting Policies	2.    SIGNIFICANT ACCOUNTING POLICIES
	Rental
	PropertyRental properties are stated at cost less accumulated depreciation and amortization.  Costs directly related to the acquisition, development and construction of rental properties are capitalized.  Acquisition–related costs are expensed as incurred.  Capitalized development and construction costs include pre-construction costs essential to the development of the property, development and construction costs, interest, property taxes, insurance, salaries and other project costs incurred during the period of development.  Capitalized development and construction salaries and related costs approximated $1.3 million and $0.9 million for the three months ended March 31, 2015 and 2014, respectively.  Included in total rental property is construction, tenant improvement and development in-progress of $67.9 million and $62.8 million as of March 31, 2015 and December 31, 2014, respectively.  Ordinary repairs and maintenance are expensed as incurred; major replacements and betterments, which improve or extend the life of the asset, are capitalized and depreciated over their estimated useful lives.  Fully-depreciated assets are removed from the accounts.
	The Company considers a construction project as substantially completed and held available for occupancy upon the substantial completion of tenant improvements, but no later than one year from cessation of major construction activity (as distinguished from activities such as routine maintenance and cleanup).  If portions of a rental project are substantially completed and occupied by tenants, or held available for occupancy, and other portions have not yet reached that stage, the substantially completed portions are accounted for as a separate project.  The Company allocates costs incurred between the portions under construction and the portions substantially completed and held available for occupancy, primarily based on a percentage of the relative square footage of each portion, and capitalizes only those costs associated with the portion under construction.
	Properties are depreciated using the straight-line method over the estimated useful lives of the assets.  The estimated useful lives are as follows:
	Leasehold interests	Remaining lease term
	Buildings and improvements	5 to 40 years
	Tenant improvements	The shorter of the term of the
		related lease or useful life
	Furniture, fixtures and equipment	5 to 10 years
	Upon acquisition of rental property, the Company estimates the fair value of acquired tangible assets, consisting of land, building and improvements, and identified intangible assets and liabilities assumed, generally consisting of the fair value of (i) above and below market leases, (ii) in-place leases and (iii) tenant relationships.  The Company allocates the purchase price to the assets acquired and liabilities assumed based on their fair values.  The Company records goodwill or a gain on bargain purchase (if any) if the net assets acquired/liabilities assumed exceed the purchase consideration of a transaction.  In estimating the fair value of the tangible and intangible assets acquired, the Company considers information obtained about each property as a result of its due diligence and marketing and leasing activities, and utilizes various valuation methods, such as estimated cash flow projections utilizing appropriate discount and capitalization rates, estimates of replacement costs net of depreciation, and available market information.  The fair value of the tangible assets of an acquired property considers the value of the property as if it were vacant.
	Above-market and below-market lease values for acquired properties are initially recorded based on the present value (using a discount rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to each in-place lease and (ii) management’s estimate of fair market lease rates for each corresponding in-place lease, measured over a period equal to the remaining term of the lease for above-market leases and the remaining initial term plus the term of any below-market fixed rate renewal options for below-market leases. The capitalized above-market lease values are amortized as a reduction of base rental revenue over the remaining terms of the respective leases, and the capitalized below-market lease values are amortized as an increase to base rental revenue over the remaining initial terms plus the terms of any below-market fixed rate renewal options of the respective leases.
	Other intangible assets acquired include amounts for in-place lease values and tenant relationship values, which are based on management’s evaluation of the specific characteristics of each tenant’s lease and the Company’s overall relationship with the respective tenant.  Factors to be considered by management in its analysis of in-place lease values include an estimate of carrying costs during hypothetical expected lease-up periods considering current market conditions, and costs to execute similar leases.  In estimating carrying costs, management includes real estate taxes, insurance and other operating expenses and estimates of lost rentals at market rates during the expected lease-up periods, depending on local market conditions.  In estimating costs to execute similar leases, management considers leasing commissions, legal and other related expenses.  Characteristics considered by management in valuing tenant relationships include the nature and extent of the Company’s existing business relationships with the tenant, growth prospects for developing new business with the tenant, the tenant’s credit quality and expectations of lease renewals.  The value of in-place leases are amortized to expense over the remaining initial terms of the respective leases.  The value of tenant relationship intangibles are amortized to expense over the anticipated life of the relationships.
	On a periodic basis, management assesses whether there are any indicators that the value of the Company’s rental properties held for use may be impaired.  In addition to identifying any specific circumstances which may affect a property or properties, management considers other criteria for determining which properties may require assessment for potential impairment.  The criteria considered by management include reviewing low leased percentages, significant near-term lease expirations, recently acquired properties, current and historical operating and/or cash flow losses, near-term mortgage debt maturities or other factors that might impact the Company’s intent and ability to hold the property.  A property’s value is impaired only if management’s estimate of the aggregate future cash flows (undiscounted and without interest charges) to be generated by the property is less than the carrying value of the property.  To the extent impairment has occurred, the loss shall be measured as the excess of the carrying amount of the property over the fair value of the property.  The Company’s estimates of aggregate future cash flows expected to be generated by each property are based on a number of assumptions.  These assumptions are generally based on management’s experience in its local real estate markets and the effects of current market conditions.  The assumptions are subject to economic and market uncertainties including, among others, demand for space, competition for tenants, changes in market rental rates, and costs to operate each property.  As these factors are difficult to predict and are subject to future events that may alter management’s assumptions, the future cash flows estimated by management in its impairment analyses may not be achieved, and actual losses or impairments may be realized in the future.
	Rental Property
	Held for SaleWhen assets are identified by management as held for sale, the Company discontinues depreciating the assets and estimates the sales price, net of selling costs, of such assets.  If, in management’s opinion, the estimated net sales price of the assets which have been identified as held for sale is less than the net book value of the assets, a valuation allowance is established.
	If circumstances arise that previously were considered unlikely and, as a result, the Company decides not to sell a property previously classified as held for sale, the property is reclassified as held and used.  A property that is reclassified is measured and recorded individually at the lower of (a) its carrying amount before the property was classified as held for sale, adjusted for any depreciation (amortization) expense that would have been recognized had the property been continuously classified as held and used, or (b) the fair value at the date of the subsequent decision not to sell.
	Investments in
	Unconsolidated
	Joint VenturesThe Company accounts for its investments in unconsolidated joint ventures under the equity method of accounting.  The Company applies the equity method by initially recording these investments at cost, as Investments in Unconsolidated Joint Ventures, subsequently adjusted for equity in earnings and cash contributions and distributions.  The outside basis portion of the Company’s joint ventures is amortized over the anticipated useful lives of the underlying ventures’ tangible and intangible assets acquired and liabilities assumed.  Generally, the Company would discontinue applying the equity method when the investment (and any advances) is reduced to zero and would not provide for additional losses unless the Company has guaranteed obligations of the venture or is otherwise committed to providing further financial support for the investee.    If the venture subsequently generates income, the Company only recognizes its share of such income to the extent it exceeds its share of previously unrecognized losses.
	On a periodic basis, management assesses whether there are any indicators that the value of the Company’s investments in unconsolidated joint ventures may be impaired.  An investment is impaired only if management’s estimate of the value of the investment is less than the carrying value of the investment, and such decline in value is deemed to be other than temporary.  To the extent impairment has occurred, the loss shall be measured as the excess of the carrying amount of the investment over the value of the investment.  The Company’s estimates of value for each investment (particularly in real estate joint ventures) are based on a number of assumptions that are subject to economic and market uncertainties including, among others, demand for space, competition for tenants, changes in market rental rates, and operating costs.  As these factors are difficult to predict and are subject to future events that may alter management’s assumptions, the values estimated by management in its impairment analyses may not be realized, and actual losses or impairment may be realized in the future.  See Note 4: Investments in Unconsolidated Joint Ventures.
	Cash and Cash
	EquivalentsAll highly liquid investments with a maturity of three months or less when purchased are considered to be cash equivalents.
	Deferred
	Financing CostsCosts incurred in obtaining financing are capitalized and amortized over the term of the related indebtedness. Amortization of such costs is included in interest expense and was $953,000 and $769,000 for the three months ended March 31, 2015 and 2014, respectively.  If a financing obligation is extinguished early, any unamortized deferred financing costs are written off and included in gains (loss) from early extinguishment of debt.    No such unamortized costs were written off for the three months ended March 31, 2015 and 2014.
	Deferred
	Leasing CostsCosts incurred in connection with commercial leases are capitalized and amortized on a straight-line basis over the terms of the related leases and included in depreciation and amortization.  Unamortized deferred leasing costs are charged to amortization expense upon early termination of the lease.  Certain employees of the Company are compensated for providing leasing services to the Properties.  The portion of such compensation related to commercial leases, which is capitalized and amortized, approximated $970,000 and $1,031,000 for the three months ended March 31, 2015 and 2014, respectively.
	GoodwillGoodwill represents the excess of the purchase price over the fair value of net tangible and intangible assets acquired in a business combination. Goodwill is allocated to various reporting units, as applicable.  Each of the Company’s segments consists of a reporting unit. Goodwill is not amortized.  Management performs an annual impairment test for goodwill during the fourth quarter and between annual tests, management evaluates the recoverability of goodwill whenever events or changes in circumstances indicate that the carrying amount of goodwill may not be fully recoverable.  In its impairment tests of goodwill, management first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount.  If based on this assessment, management determines that the fair value of the reporting unit is not less than its carrying amount, then performing the additional two-step impairment test is unnecessary. If the carrying amount of goodwill exceeds its fair value, an impairment charge is recognized.
	Derivative
	InstrumentsThe Company measures derivative instruments, including certain derivative instruments embedded in other contracts, at fair value and records them as an asset or liability, depending on the Company’s rights or obligations under the applicable derivative contract.  For derivatives designated and qualifying as fair value hedges, the changes in the fair value of both the derivative instrument and the hedged item are recorded in earnings.  For derivatives designated as cash flow hedges, the effective portions of the derivative are reported in other comprehensive income (“OCI”) and are subsequently reclassified into earnings when the hedged item affects earnings. Changes in fair value of derivative instruments not designated as hedging and ineffective portions of hedges are recognized in earnings in the affected period.
	Revenue
	RecognitionBase rental revenue is recognized on a straight-line basis over the terms of the respective leases.  Unbilled rents receivable represents the cumulative amount by which straight-line rental revenue exceeds rents currently billed in accordance with the lease agreements.
	Above-market and below-market lease values for acquired properties are initially recorded based on the present value (using a discount rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to each in-place lease and (ii) management’s estimate of fair market lease rates for each corresponding in-place lease, measured over a period equal to the remaining term of the lease for above-market leases and the remaining initial term plus the term of any below-market fixed-rate renewal options for below-market leases.  The capitalized above-market lease values for acquired properties are amortized as a reduction of base rental revenue over the remaining terms of the respective leases, and the capitalized below-market lease values are amortized as an increase to base rental revenue over the remaining initial terms plus the terms of any below-market fixed-rate renewal options of the respective leases.
	Escalations and recoveries from tenants are received from tenants for certain costs as provided in the lease agreements.  These costs generally include real estate taxes, utilities, insurance, common area maintenance and other recoverable costs.  See Note 13: Tenant Leases.
	Real estate services revenue includes property management, development, construction and leasing commission fees and other services, and payroll and related costs reimbursed from clients.  Fee income derived from the Company’s unconsolidated joint ventures (which are capitalized by such ventures) are recognized to the extent attributable to the unaffiliated ownership interests.
	Parking income includes income from parking spaces leased to tenants and others.
	Other income includes income from tenants for additional services arranged for by the Company and income from tenants for early lease terminations.
	Allowance for
	Doubtful AccountsManagement performs a detailed review of amounts due from tenants to determine if an allowance for doubtful accounts is required based on factors affecting the collectability of the accounts receivable balances. The factors considered by management in determining which individual tenant receivable balances, or aggregate receivable balances, require a collectability allowance include the age of the receivable, the tenant’s payment history, the nature of the charges, any communications regarding the charges and other related information. Management’s estimate of the allowance for doubtful accounts requires management to exercise significant judgment about the timing, frequency and severity of collection losses, which affects the allowance and net income.
	Income and
	Other TaxesThe Company has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “Code”).  As a REIT, the Company generally will not be subject to corporate federal income tax (including alternative minimum tax) on net income that it currently distributes to its shareholders, provided that the Company satisfies certain organizational and operational requirements including the requirement to distribute at least 90 percent of its REIT taxable income (determined by excluding any net capital gains) to its shareholders.  If and to the extent the Company retains and does not distribute any net capital gains, the Company will be required to pay federal, state and local taxes on such net capital gains at the rate applicable to capital gains of a corporation.  The Company has elected to treat certain of its corporate subsidiaries as taxable REIT subsidiaries (each a “TRS”).  In general, a TRS of the Company may perform additional services for tenants of the Company and generally may engage in any real estate or non-real estate related business (except for the operation or management of health care facilities or lodging facilities or the providing to any person, under a franchise, license or otherwise, rights to any brand name under which any lodging facility or health care facility is operated).  A TRS is subject to corporate federal income tax.   The Company has conducted business through its TRS entities for certain property management, development, construction and other related services, as well as to hold a joint venture interest in a hotel and other matters.
	As of March 31, 2015, the Company had a deferred tax asset related to its TRS activity with a balance of approximately $15.2 million which has been fully reserved for through a valuation allowance.  If the Company fails to qualify as a REIT in any taxable year, the Company will be subject to federal income tax (including any applicable alternative minimum tax) on its taxable income at regular corporate tax rates.  The Company is subject to certain state and local taxes.
	Pursuant to the amended provisions related to uncertain tax provisions of ASC 740, Income Taxes, the Company recognized no material adjustments regarding its tax accounting treatment.  The Company expects to recognize interest and penalties related to uncertain tax positions, if any, as income tax expense, which is included in general and administrative expense.
	In the normal course of business, the Company or one of its subsidiaries is subject to examination by federal, state and local jurisdictions in which it operates, where applicable.  As of March 31, 2015, the tax years that remain subject to examination by the major tax jurisdictions under the statute of limitations are generally from the year 2010 forward.
	Earnings
	Per ShareThe Company presents both basic and diluted earnings per share (“EPS”).  Basic EPS excludes dilution and is computed by dividing net income available to common shareholders by the weighted average number of shares outstanding for the period.  Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock, where such exercise or conversion would result in a lower EPS from continuing operations amount.  Shares whose issuance is contingent upon the satisfaction of certain conditions shall be considered outstanding and included in the computation of diluted EPS as follows (i) if all necessary conditions have been satisfied by the end of the period (the events have occurred), those shares shall be included as of the beginning of the period in which the conditions were satisfied (or as of the date of the grant, if later) or (ii) if all necessary conditions have not been satisfied by the end of the period, the number of contingently issuable shares included in diluted EPS shall be based on the number of shares, if any, that would be issuable if the end of the reporting period were the end of the contingency period (for example, the number of shares that would be issuable based on current period earnings or period-end market price) and if the result would be dilutive. Those contingently issuable shares shall be included in the denominator of diluted EPS as of the beginning of the period (or as of the date of the grant, if later).
	Dividends and
	Distributions
	PayableThe dividends and distributions payable at March 31, 2015 represents dividends payable to common shareholders (88,918,291 shares) and distributions payable to noncontrolling interest common unitholders of the Operating Partnership (11,036,898 common units) for all such holders of record as of April 6, 2015 with respect to the first quarter 2015.  The first quarter 2015 common stock dividends and common unit distributions of $0.15 per common share and unit were approved by the Board of Directors on March 10, 2015 and paid on April 14, 2015.
	The dividends and distributions payable at December 31, 2014 represents dividends payable to common shareholders (88,866,652 shares) and distributions payable to noncontrolling interest common unitholders of the Operating Partnership (11,083,876 common units) for all such holders of record as of January 6, 2015 with respect to the fourth quarter 2014.  The fourth quarter 2014 common stock dividends and common unit distributions of $0.15 per common share and unit were approved by the Board of Directors on December 9, 2014 and paid on January 14, 2015.
	Costs Incurred
	For Stock
	IssuancesCosts incurred in connection with the Company’s stock issuances are reflected as a reduction of additional paid‑in capital.
	Stock
	CompensationThe Company accounts for stock compensation in accordance with the provisions of ASC 718, Compensation-Stock Compensation.  These provisions require that the estimated fair value of restricted stock (“Restricted Stock Awards”), total stockholder return (“TSR”) based performance shares and stock options at the grant date be amortized ratably into expense over the appropriate vesting period.  The Company recorded stock compensation expense of $313,000 and $3,387,000 for the three months ended March 31, 2015 and 2014, respectively.  The amount for the three months ended March 31, 2014 included $3,203,000 related to the departure of executive officers.  See Note 12: Commitments and Contingencies ‑ Departure of Executive Officers.
	Other
	Comprehensive
	IncomeOther comprehensive income (loss), if any, includes items that are recorded in equity, such as unrealized holding gains or losses on marketable securities available for sale.  There was no difference in other comprehensive income to net income for the three months ended March 31, 2015 and 2014, and no accumulated other comprehensive income as of March 31, 2015 and December 31, 2014.
	Fair Value
	HierarchyThe standard Fair Value Measurements specifies a hierarchy of valuation techniques based upon whether the inputs to those valuation techniques reflect assumptions other market participants would use based upon market data obtained from independent sources (observable inputs).  The following summarizes the fair value hierarchy:
		·	Level 1: Quoted prices in active markets that are unadjusted and accessible at the measurement date for identical, unrestricted assets or liabilities;
		·	Level 2: Quoted prices for identical assets and liabilities in markets that are inactive, quoted prices for similar assets and liabilities in active markets or financial instruments for which significant inputs are observable, either directly or indirectly, such as interest rates and yield curves that are observable at commonly quoted intervals and
		·	Level 3: Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable.
	In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy.  In such cases, the level in the fair value hierarchy within which the fair value measurement in its entirety falls has been determined based on the lowest level input that is significant to the fair value measurement in its entirety.  The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability.
Discontinued
OperationsIn April 2014, the FASB issued guidance related to the reporting of discontinued operation and disclosures of disposals of components of an entity.  This guidance defines a discontinued operation as a component or group of components disposed or classified as held for sale and represents a strategic shift that has (or will have) a major effect on an entity’s operations and final result; the guidance states that a strategic shift could include a disposal of a major geographical area of operations, a major line of business, a major equity method investment or other major parts of an entity.  The guidance also provides for additional disclosure requirements in connection with both discontinued operations and other dispositions not qualifying as discontinued operations.  The guidance is effective for all companies for annual and interim periods beginning on or after December 15, 2014.  The guidance applies prospectively to new disposals and new classifications of disposal groups as held for sale after the effective date.  All entities could early adopt the guidance for new disposals (or new classifications as held for sale) that had not been reported in financial statements previously issued or available for issuance.    The Company elected to early adopt this standard effective with the interim period beginning January 1, 2014.    Prior to January 1, 2014, properties identified as held for sale and/or disposed of were presented in discontinued operations for all periods presented.
Impact Of
Recently-Issued
Accounting
StandardsIn May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09 Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"). ASU 2014-09 is a comprehensive new revenue recognition model requiring a company to recognize revenue to depict the transfer of goods or services to a customer at an amount reflecting the consideration it expects to receive in exchange for those goods or services. In adopting ASU 2014-09, companies may use either a full retrospective or a modified retrospective approach. Additionally, this guidance requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers.  ASU 2014-09 is effective for the first interim period within annual reporting periods beginning after December 15, 2017, and early adoption is permitted for periods beginning after December 15, 2016.  The Company is currently in the process of evaluating the impact the adoption of ASU 2014-09 will have on the Company’s financial position or results of operations.
In August 2014, the FASB issued ASU 2014-15, which requires management to evaluate whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern, and to provide certain disclosures when it is probable that the entity will be unable to meet its obligations as they become due within one year after the date that the financial statements are issued. ASU 2014-15 is effective for the annual period ended December 31, 2016 and for annual periods and interim periods thereafter with early adoption permitted. The adoption of ASU 2014-15 is not expected to materially impact the Company’s consolidated financial statements.

Real_Estate_Transactions

Real Estate Transactions	3 Months Ended
	Mar. 31, 2015
Real Estate Transactions [Abstract]
Real Estate Transactions	3.    REAL ESTATE TRANSACTIONS
	On April 1, 2015, the Company acquired vacant land to accommodate the development of 370 multi-family residential units located in Worcester, Massachusetts (the “CitySquare Project”) for a purchase price of $3.1 million with an additional $1.25 million to be paid, subject to certain conditions, in accordance with the terms of the purchase and sale agreement.  The purchase price for the acquisition was funded primarily through borrowing under the Company’s unsecured revolving credit facility.  The Company is required to begin construction of the CitySquare Project within 12 months of closing.  The Company plans to start construction in the third quarter 2015 and the total development costs are estimated to be approximately $88 million.
	On January 15, 2015, the Company sold its 21,600 square foot office/flex property located at 1451 Metropolitan Drive in West Deptford, New Jersey for net sales proceeds of approximately $1.1 million, with a gain of approximately $0.1 million from the sale.
	On January 1, 2014, the Company early adopted the new discontinued operations accounting standard and as the properties sold during the three months ended March 31, 2015 and the year ended December 31, 2014, will not represent a strategic shift (as the Company is not entirely exiting markets or property types), they have not been reflected as part of discontinued operations.
	The following table summarizes income for the three month periods ended March 31, 2015 and 2014 from the property sold during the three months ended March 31, 2015 and the 16 properties sold during the year ended December 31, 2014: (dollars in thousands)
			Three Months Ended
			March 31,
			2015		2014
	Total revenues	$	8	$	14,969
	Operating and other expenses		-3		-9,253
	Depreciation and amortization		-2		-3,394
	Income from properties sold	$	3	$	2,322
	Realized gains (losses) on sales, net		144		-
	Total income (loss) from properties sold	$	147	$	2,322

Investments_In_Unconsolidated_

Investments In Unconsolidated Joint Ventures	3 Months Ended
	Mar. 31, 2015
Investments In Unconsolidated Joint Ventures [Abstract]
Investments In Unconsolidated Joint Ventures	4.    INVESTMENTS IN UNCONSOLIDATED JOINT VENTURES
	As of March 31, 2015, the Company had an aggregate investment of approximately $262.1 million in its equity method joint ventures.  The Company formed these ventures with unaffiliated third parties, or acquired interests in them, to develop or manage primarily office and multi-family rental properties, or to acquire land in anticipation of possible development of office and multi-family rental properties.  As of March 31, 2015, the unconsolidated joint ventures owned: 36 office and two retail properties aggregating approximately 5.7 million square feet, 14 multi-family properties totaling 4,560 apartments, a 350-room hotel, development projects for up to approximately 1,354 apartments; and interests and/or rights to developable land parcels able to accommodate up to 2,853 apartments and 1.4 million square feet of office space.  The Company’s unconsolidated interests range from 7.5 percent to 85 percent subject to specified priority allocations in certain of the joint ventures.
	On October 23, 2012, the Company acquired the real estate development and management businesses (the “Roseland Business”) of Roseland Partners, L.L.C. (“Roseland Partners”), a premier multi-family rental community developer and manager based in Short Hills, New Jersey, and the Roseland Partners’ interests (the “Roseland Transaction”), principally through unconsolidated joint venture interests in various entities which, directly or indirectly, own or have rights with respect to various residential and/or commercial properties or vacant land (collectively, the “Roseland Assets”).  The locations of the properties extend from New Jersey to Massachusetts, with the majority of the properties located in New Jersey.  Certain of the entities which own the Roseland Assets are controlled by the Company upon acquisition and are therefore consolidated. However, many of the entities are not controlled by the Company and, therefore, are accounted for under the equity method as investments in unconsolidated joint ventures.
	The amounts reflected in the following tables (except for the Company’s share of equity in earnings) are based on the historical financial information of the individual joint ventures.  The Company does not record losses of the joint ventures in excess of its investment balances unless the Company is liable for the obligations of the joint venture or is otherwise committed to provide financial support to the joint venture.  The outside basis portion of the Company’s investments in joint ventures is amortized over the anticipated useful lives of the underlying ventures’ tangible and intangible assets acquired and liabilities assumed.  Unless otherwise noted below, the debt of the Company’s unconsolidated joint ventures generally is non-recourse to the Company, except for customary exceptions pertaining to such matters as intentional misuse of funds, environmental conditions, and material misrepresentations.
	The Company has agreed to guarantee repayment of a portion of the debt of its unconsolidated joint ventures.  As of March 31, 2015, such debt had a total facility amount of $477 million of which the Company agreed to guarantee up to $82.8 million.  As of March 31, 2015, the outstanding balance of such debt totaled $250.7 million of which $51.9 million was guaranteed by the Company.  The Company also posted a $4.1 million letter of credit in support of the South Pier at Harborside joint venture, half of which is indemnified by Hyatt Corporation, the Company’s joint venture partner.  The Company performed management, leasing, development and other services for the properties owned by the unconsolidated joint ventures and recognized $1.6 million and $504,000 for such services in the three months ended March 31, 2015 and 2014, respectively.  The Company had $1.2 million and $1.0 million in accounts receivable due from its unconsolidated joint ventures as of March 31, 2015 and December 31, 2014.
	Included in the Company’s investments in unconsolidated joint ventures as of March 31, 2015 are nine unconsolidated development joint ventures, which are VIEs for which the Company is not the primary beneficiary.  These joint ventures are primarily established to develop real estate property for long-term investment and were deemed VIEs primarily based on the fact that the equity investment at risk was not sufficient to permit the entities to finance their activities without additional financial support.  The initial equity contributed to these entities was not sufficient to fully finance the real estate construction as development costs are funded by the partners throughout the construction period.  The Company determined that it was not the primary beneficiary of these VIEs based on the fact that the Company has shared control of these entities along with the entity’s partners and therefore does not have controlling financial interests in these VIEs.  The Company’s aggregate investment in these VIEs was approximately $129.8 million as of March 31, 2015.  The Company’s maximum exposure to loss as a result of its involvement with these VIEs is estimated to be approximately $206.4 million, which includes the Company’s current investment and estimated future funding commitments/guarantees of approximately $76.6 million.  The Company has not provided financial support to these VIEs that it was not previously contractually required to provide.  In general, future costs of development not financed through third party will be funded with capital contributions from the Company and its outside partners in accordance with their respective ownership percentages.
	The following is a summary of the Company's unconsolidated joint ventures as of March 31, 2015 and December 31, 2014: (dollars in thousands)
												Property Debt
		Number of		Company's				Carrying Amount				As of March 31, 2015
		Apartment Units		Effective				March 31,		December 31,			Maturity	Interest
	Entity / Property Name	or Square Feet (sf)		Ownership % (a)				2015		2014		Balance	Date	Rate
	Multi-family
	Marbella RoseGarden, L.L.C./ Marbella  (b)	412	units	24.27	%		$	15,839	$	15,779	$	95,000	5/1/18	4.99	%
	RoseGarden Monaco Holdings, L.L.C./ Monaco   (b)	523	units	15.00	%			1,845		2,161		165,000	2/1/21	4.19	%
	Rosewood Lafayette Holdings, L.L.C./ Highlands at Morristown Station  (b)	217	units	25.00	%			-		62		38,478	7/1/15	4.00	%
	PruRose Port Imperial South 15, LLC /RiversEdge at Port Imperial (b)	236	units	50.00	%			-		-		57,500	9/1/20	4.32	%
	Rosewood Morristown, L.L.C. / Metropolitan at 40 Park  (c) (d)	130	units	12.50	%			5,920		6,029		46,217	(e)	(e)
	Overlook Ridge JV, L.L.C./ Quarrystone at Overlook Ridge  (b)	251	units	50.00	%			-		-		69,420	(f)	(f)
	Overlook Ridge JV 2C/3B, L.L.C./The Chase at Overlook Ridge  (b)	371	units	50.00	%			2,304		2,524		51,447	12/26/15	L+2.50	%	(g)
	PruRose Riverwalk G, L.L.C./ RiverTrace at Port Imperial   (b)	316	units	25.00	%			701		955		79,154	7/15/21	6.00	%	(h)
	Elmajo Urban Renewal Associates, LLC / Lincoln Harbor (Bldg A&C) (b)	355	units	7.50	%			-		-		128,100	3/1/30	4.00	%	(i)
	Crystal House Apartments Investors LLC / Crystal House  (j)	828	units	25.00	%			27,340		27,051		165,000	4/1/20	3.17	%
	Portside Master Company, L.L.C./ Portside at Pier One - Bldg 7  (b)	176	units	38.25	%			1,017		1,747		38,990	12/4/15	L+2.50	%	(k)
	PruRose Port Imperial South 13, LLC / RiverParc at Port Imperial  (b)	280	units	20.00	%			815		1,087		56,999	6/27/16	L+2.15	%	(l)
	Roseland/Port Imperial Partners, L.P./ Riverwalk C  (b) (m)	363	units	20.00	%			1,755		1,800		-	-	-
	RoseGarden Marbella South, L.L.C./ Marbella II	311	units	24.27	%			12,920		11,282		43,090	3/30/17	L+2.25	%	(n)
	Estuary Urban Renewal Unit B, LLC / Lincoln Harbor (Bldg B)  (b)	227	units	7.50	%			-		-		81,900	3/1/30	4.00	%	(o)
	Riverpark at Harrison I, L.L.C./ Riverpark at Harrison	141	units	36.00	%			4,571		4,744		23,095	6/27/16	L+2.35	%	(p)
	Capitol Place Mezz LLC / Station Townhouses	377	units	50.00	%			49,873		49,327		73,971	7/1/33	4.82	%	(q)
	Harborside Unit A Urban Renewal, L.L.C. / URL Harborside	763	units	85.00	%			52,263		34,954		-	8/1/29	5.197	%	(r)
	RoseGarden Monaco, L.L.C./ San Remo Land	300	potential units	41.67	%			1,283		1,283		-	-	-
	Grand Jersey Waterfront URA, L.L.C./ Liberty Landing	1,000	potential units	50.00	%			337		337		-	-	-
	Office
	Red Bank Corporate Plaza, L.L.C./ Red Bank	92,878	sf	50.00	%			4,081		3,963		15,682	5/17/16	L+3.00	%	(s)
	12 Vreeland Associates, L.L.C./ 12 Vreeland Road	139,750	sf	50.00	%			5,606		5,620		13,679	7/1/23	2.87	%
	BNES Associates III / Offices at Crystal Lake	106,345	sf	31.25	%			2,061		1,993		6,603	11/1/23	4.76	%
	Hillsborough 206 Holdings, L.L.C./ Hillsborough 206	160,000	sf	50.00	%			1,962		1,962		-	-	-
	KPG-P 100 IMW JV, LLC / 100 Independence Mall West	339,615	sf	33.33	%			416		-		61,500	9/9/16	L+7.00	%	(t)
	Keystone-Penn	1,842,820	sf	(u)				-		-		205,946	(v)	(v)
	Keystone-TriState	1,266,384	sf	(w)				4,792		6,140		205,112	(x)	(x)
	KPG-MCG Curtis JV, L.L.C./ Curtis Center  (y)	885,000	sf	50.00	%			58,341		59,911		(z)	(z)	(z)
	Other
	Plaza VIII & IX Associates, L.L.C./ Vacant land (parking operations)	1,225,000	sf	50.00	%			3,796		4,022		-	-	-
	Roseland/North Retail, L.L.C./ Riverwalk at Port Imperial  (b)	30,745	sf	20.00	%			1,810		1,828		-	-	-
	South Pier at Harborside / Hyatt Regency Jersey City on the Hudson	350	rooms	50.00	%			(aa)		(aa)		65,308	(ab)	(ab)
	Stamford SM LLC / Senior Mezzanine Loan  (ac)	n/a	n/a	80.00	%			-		-		-	-	-
	Other (ad)							404		907		-	-	-
	Totals:						$	262,052	$	247,468	$	1,787,191
	(a)	Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.
	(b)	The Company's ownership interests in this venture are subordinate to its partner's preferred capital balance and the Company is not expected to meaningfully participate in the venture's cash flows in the near term.
	(c)	Through the joint venture, the Company also owns a 12.5 percent interest in a 50,973 square feet retail building ("Shops at 40 Park") and a 25 percent interest in a to-be-built 59-unit, five story multi-family rental development property ("Lofts at 40 Park").
	(d)	The Company's ownership interests in this venture are subordinate to its partner's preferred capital balance and the payment of the outstanding balance remaining on a note ($975 as of March 31, 2015), and is not expected to meaningfully participate in the venture's cash flows in the near term.
	(e)	Property debt balance consists of: (i) a loan, collateralized by the Metropolitan at 40 Park, with a balance of $38,600 at March 31, 2015, bears interest at 3.25 percent, matures in September 2020 and is interest only through September 2015; (ii) a loan, collateralized by the Shops at 40 Park, with a balance of $6,500 at March 31, 2015, bears interest at 3.63 percent, matures in August 2018 and is interest-only through July 2015; and (iii) a loan, collateralized by the Lofts at 40 Park, with a balance of $1,117, bears interest at LIBOR plus 250 basis points and matures in September 2015.  The Shops at 40 Park mortgage loan also provides for additional borrowing proceeds of $1 million based on certain preferred thresholds being achieved.
	(f)	Property debt balance consists of: (i) the senior loan, collateralized by the Quarrystone property, with a balance of $52,420 at March 31, 2015, bears interest at LIBOR plus 200 basis, matures in March 2016 and (ii) the junior loan, with a balance of $17,000, bears interest at LIBOR plus 90 basis points, matures in March 2016 and is collateralized by a $17,000 letter of credit provided by an affiliate of the partner.
	(g)	The construction loan has a maximum borrowing amount of $55,500 and provides, subject to certain conditions, two one-year extension options with a fee of 25 basis points each.  The joint venture has a swap agreement that fixes the all-in rate to 3.0875 percent per annum on an initial notional amount of $1,840, increasing to $52,000, for the period from September 3, 2013 to November 2, 2015.
	(h)	The permanent loan has a maximum borrowing amount of $80,249.
	(i)	The construction loan with a maximum borrowing amount of $91,000 converted to a permanent loan on February 27, 2015.
	(j)	The Company also owns a 50 percent interest in a vacant land to accommodate the development of approximately 295 additional units of which 252 are currently approved.
	(k)	The construction loan has a maximum borrowing amount of $42,500 and provides, subject to certain conditions, two two-year extension options with a fee of 12.5 basis points for the first two-year extension and 25 basis points for the second two-year extension.
	(l)	The construction loan has a maximum borrowing amount of $73,350 and provides, subject to certain conditions, one-year extension option followed by a six-month extension option with a fee of 25 basis points each. The joint venture has a swap agreement that fixes the all-in rate to 2.79 percent per annum on an initial notional amount of $1,620, increasing to $69,500 for the period from July 1, 2013 to January 1, 2016.
	(m)	The Company also owns a 20 percent residual interest in undeveloped land parcels: parcels 6, I, and J ("Port Imperial North Land") that can accommodate the development of 836 apartment units.
	(n)	The construction loan has a maximum borrowing amount of $77,400 and provides, subject to certain conditions, two one-year extension options with a fee of 25 basis points for each year.
	(o)	The construction loan with a maximum borrowing amount of $57,000 converted to a permanent loan on February 27, 2015.
	(p)	The construction loan has a maximum borrowing amount of $23,400 and provides, subject to certain conditions, two one-year extension options with a fee of 20 basis points for each year.
(q)	The construction/permanent loan has a maximum borrowing amount of $100,700 with amortization starting in August 2017.
(r)	The construction/permanent loan has a maximum borrowing amount of $192,000.
(s)	The joint venture has a swap agreement that fixes the all-in rate to 3.99375 percent per annum on an initial notional amount of $13,650 and then adjusting in accordance with an amortization schedule, which is effective from October 17, 2011 through loan maturity.
(t)	The mortgage loan has two one-year extension options, subject to certain conditions, and includes a $25 million construction escrow with a balance of $13.6 million to be drawn at March 31, 2015.
(u)	The Company’s equity interests in the joint ventures will be subordinated to Keystone Entities receiving a 15 percent internal rate of return (“IRR”) after which the Company will receive a 10 percent IRR on its subordinate equity and then all profit will be split equally.
(v)	Principal balance of $127,600 bears interest at 5.114 percent and matures in August 27, 2023; principal balance of $67,921 bears interest at rates ranging from LIBOR+5.0 percent to LIBOR+5.75 percent and matures in August 27, 2016; principal balance of $10,425 bears interest at LIBOR+6.0 percent matures in August 27, 2015.
(w)	Includes the Company’s pari-passu interests of $4.8 million in five properties and Company’s subordinated equity interests to Keystone Entities receiving a 15 percent internal rate of return (“IRR”) after which the Company will receive a 10 percent IRR on its subordinate equity and then all profit will be split equally.
(x)	Principal balance of $41,240 bears interest at 4.95 percent and matures on July 1, 2017; principal balance of $71,172 bears interest at rates ranging from 5.65 percent to 6.75 percent and matures on September 9, 2017; principal balance of $14,250 bears interest at 4.88 percent and matures on July 6, 2024; principal balance of $63,400 bears interest at 4.93 percent and matures on July 6, 2044; principal balance of $15,050 bears interest at 4.71 percent and matures on August 6, 2044.
(y)	Includes undivided interests in the same manner as investments in noncontrolling partnership, pursuant to ASC 970-323-25-12.
(z)	See Note 9: Mortgages, Loans Payable and Other Obligations for debt secured by interests in these assets.
(aa)	The negative carrying amount for this venture of $1,937 and $1,854 as of March 31, 2015 and December 31, 2014, respectively, were included in accounts payable, accrued expenses and other liabilities.
(ab)	Balance includes: (i) mortgage loan, collateralized by the hotel property, with a balance of $61,184, bears interest at 6.15 percent and matures in November 2016, and (ii) loan with a balance of $4.1 million, bears interest at fixed rates ranging from 6.09 percent to 6.62 percent and matures in August 1, 2020.  The Company posted a $4.1 million letter of credit in support of this loan, half of which is indemnified by the partner.
(ac)	The joint venture collected net proceeds of $47.2 million at maturity, of which the Company received its share of $37.8 million on August 6, 2014.
(ad)	The Company owns other interests in various unconsolidated joint ventures, including interests in assets previously owned and interest in ventures whose businesses are related to its core operations. These ventures are not expected to significantly impact the Company's operations in the near term.
The following is a summary of the Company’s equity in earnings (loss) of unconsolidated joint ventures for the three months ended March 31, 2015 and 2014: (dollars in thousands)
		Three Months Ended
		March 31,
Entity / Property Name		2015			2014
Multi-family
Marbella RoseGarden, L.L.C./ Marbella	$	61		$	-6
RoseGarden Monaco Holdings, L.L.C./ Monaco		-317			-277
Rosewood Lafayette Holdings, L.L.C./ Highlands at Morristown Station		-62			-216
PruRose Port Imperial South 15, LLC /RiversEdge at Port Imperial		-			-
Rosewood Morristown, L.L.C. / Metropolitan at 40 Park		-94			-98
Overlook Ridge JV, L.L.C./ Quarrystone at Overlook Ridge		-			-
Overlook Ridge JV 2C/3B, L.L.C./The Chase at Overlook Ridge		-220			62
PruRose Riverwalk G, L.L.C./ RiverTrace at Port Imperial		-254			-538
Elmajo Urban Renewal Associates, LLC / Lincoln Harbor (Bldg A&C)		-			-112
Crystal House Apartments Investors LLC / Crystal House		-10			-327
Portside Master Company, L.L.C./ Portside at Pier One - Bldg 7		-719			-213
PruRose Port Imperial South 13, LLC / RiverParc at Port Imperial		-225			-206
Roseland/Port Imperial Partners, L.P./ Riverwalk C		-184			-164
RoseGarden Marbella South, L.L.C./ Marbella II		-			-
Estuary Urban Renewal Unit B, LLC / Lincoln Harbor (Bldg B)		-			-15
Riverpark at Harrison I, L.L.C./ Riverpark at Harrison		-173			-
Capitol Place Mezz LLC / Station Townhouses		75			-
Harborside Unit A Urban Renewal, L.L.C. / URL Harborside		-			-
RoseGarden Monaco, L.L.C./ San Remo Land		-			-
Grand Jersey Waterfront URA, L.L.C./ Liberty Landing		-19			-37
Office
Red Bank Corporate Plaza, L.L.C./ Red Bank		110			99
12 Vreeland Associates, L.L.C./ 12 Vreeland Road		-14			89
BNES Associates III / Offices at Crystal Lake		68			36
Hillsborough 206 Holdings, L.L.C./ Hillsborough 206		-			-5
KPG-P 100 IMW JV, LLC / 100 Independence Mall West		-384			-653
Keystone-Penn		-			-
Keystone-TriState		-1,348			-
KPG-MCG Curtis JV, L.L.C./ Curtis Center		196			-
Other
Plaza VIII & IX Associates, L.L.C./ Vacant land (parking operations)		86			102
Roseland/North Retail, L.L.C./ Riverwalk at Port Imperial		-18			-24
South Pier at Harborside / Hyatt Regency Jersey City on the Hudson		-84			398
Stamford SM LLC / Senior Mezzanine Loan		-			916
Other		-			-46
Company's equity in earnings (loss) of unconsolidated joint ventures	$	-3,529		$	-1,235
The following is a summary of the financial position of the unconsolidated joint ventures in which the Company had investment interests as of March 31, 2015 and December 31, 2014: (dollars in thousands)
			March 31,			December 31,
			2015			2014
Assets:
Rental property, net		$	1,546,589		$	1,534,812
Other assets			410,410			398,222
Total assets		$	1,956,999		$	1,933,034
Liabilities and partners'/
members' capital:
Mortgages and loans payable		$	1,162,732		$	1,060,020
Other liabilities			214,572			211,340
Partners'/members' capital			579,695			661,674
Total liabilities and
partners'/members' capital		$	1,956,999		$	1,933,034
The following is a summary of the results from operations of the unconsolidated joint ventures for the period in which the Company had investment interests during the three months ended March 31, 2015 and 2014:  (dollars in thousands)
		Three Months Ended
		March 31,
		2015			2014
Total revenues	$	74,477		$	30,993
Operating and other expenses		-57,356			-18,353
Depreciation and amortization		-16,993			-8,368
Interest expense		-11,334			-6,341
Net loss	$	-11,206		$	-2,069

Deferred_Charges_Goodwill_And_

Deferred Charges, Goodwill And Other Assets	3 Months Ended
	Mar. 31, 2015
Deferred Charges, Goodwill And Other Assets [Abstract]
Deferred Charges, Goodwill And Other Assets	5.    DEFERRED CHARGES, GOODWILL AND OTHER ASSETS, NET
			March 31,			December 31,
	(dollars in thousands)		2015			2014
	Deferred leasing costs	$	226,649		$	239,138
	Deferred financing costs		20,755			24,042
			247,404			263,180
	Accumulated amortization		-107,601			-122,358
	Deferred charges, net		139,803			140,822
	Notes receivable (a)		21,430			21,491
	In-place lease values, related intangibles and other assets, net		6,021			6,565
	Goodwill		2,945			2,945
	Prepaid expenses and other assets, net		40,561			32,827
	Total deferred charges, goodwill and other assets, net	$	210,760		$	204,650
	(a)Includes as of March 31, 2015: a mortgage receivable for $10.4 million which bears interest at LIBOR plus six percent and matures in August 2015; a note receivable for $7.8 million which bears interest at eight percent and matures in October 2017 (which was repaid in full to the Company on April 15, 2015); and an interest-free note receivable with a net present value of $3.3 million and matures in April 2023.  The Company believes these balances are fully collectible.
	DERIVATIVE FINANCIAL INSTRUMENTS
	The Company does not have any derivative instruments designated as cash flow hedges.  The following table summarizes the notional and fair value of the Company’s derivative financial instruments, designated as fair value hedges, as of March 31, 2015 and December 31, 2014 (dollars in thousands):
										Fair Value
			Notional			Strike		Effective	Expiration		March 31,		December 31,
			Value	(a)		Rate		Date	Date		2015		2014
	LIBOR Cap	$	51,000			1.5	%	Sep-14	Oct-15	$	1	$	1
	LIBOR Cap		24,000			1.5	%	Sep-14	Oct-15		1		1
	LIBOR Cap		51,000			1.75	%	Oct-15	Oct-16		20		64
	LIBOR Cap		24,000			1.75	%	Oct-15	Oct-16		10		29
										$	32	$	95
		(a)		The notional value is an indication of the extent of our involvement in these instruments at that time, but does not represent exposure to credit, interest rate or market risks.
	The Company includes these derivative financial instruments in deferred charges, goodwill and other assets, net.  As changes in the fair value of these derivative financial instruments are recorded in earnings, the Company recorded a loss on the change in fair value of $63,000 during the three months ended March 31, 2015,  which is included in interest and other investment income in the consolidated statements of operations.

Restricted_Cash

Restricted Cash	3 Months Ended
	Mar. 31, 2015
Restricted Cash [Abstract]
Restricted Cash	6.    RESTRICTED CASH
	Restricted cash generally includes tenant and resident security deposits for certain of the Company’s properties, and escrow and reserve funds for debt service, real estate taxes, property insurance, capital improvements, tenant improvements, and leasing costs established pursuant to certain mortgage financing arrangements, and is comprised of the following:  (dollars in thousands)
			March 31,		December 31,
			2015		2014
	Security deposits	$	7,868	$	7,795
	Escrow and other reserve funds		27,912		26,450
	Total restricted cash	$	35,780	$	34,245

Senior_Unsecured_Notes

Senior Unsecured Notes	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Senior Unsecured Notes	7.    SENIOR UNSECURED NOTES
	A summary of the Company’s senior unsecured notes as of March 31, 2015 and December 31, 2014 is as follows:  (dollars in thousands)
			March 31,		December 31,	Effective
			2015		2014	Rate (1)
	5.800% Senior Unsecured Notes, due January 15, 2016	$	200,066	$	200,086	5.806	%
	2.500% Senior Unsecured Notes, due  December 15, 2017		249,224		249,150	2.803	%
	7.750% Senior Unsecured Notes, due August 15, 2019		249,066		249,013	8.017	%
	4.500% Senior Unsecured Notes, due April 18, 2022		299,580		299,565	4.612	%
	3.150% Senior Unsecured Notes, due May 15, 2023		270,082		269,930	3.517	%
	Total senior unsecured notes	$	1,268,018	$	1,267,744
	(1)Includes the cost of terminated treasury lock agreements (if any), offering and other transaction costs and the discount/premium on the notes, as applicable.
	The terms of the Company’s senior unsecured notes include certain restrictions and covenants which require compliance with financial ratios relating to the maximum amount of debt leverage, the maximum amount of secured indebtedness, the minimum amount of debt service coverage and the maximum amount of unsecured debt as a percent of unsecured assets.   The Company was in compliance with its debt covenants under the indenture relating to its senior unsecured notes as of March 31, 2015.

Unsecured_Revolving_Credit_Fac

Unsecured Revolving Credit Facility	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Unsecured Revolving Credit Facility	8.    UNSECURED REVOLVING CREDIT FACILITY
	On July 16, 2013, the Company amended and restated its unsecured revolving credit facility with a group of 17 lenders.  The $600 million facility is expandable to $1 billion and matures in July 2017.  It has two six-month extension options each requiring the payment of a 7.5 basis point fee.  The interest rate on outstanding borrowings (not electing the Company’s competitive bid feature) and the facility fee on the current borrowing capacity payable quarterly in arrears are based upon the Operating Partnership’s unsecured debt ratings, as follows:
	Operating Partnership's	Interest Rate -
	Unsecured Debt Ratings:	Applicable Basis Points	Facility Fee
	Higher of S&P or Moody's	Above LIBOR	Basis Points
	No ratings or less than BBB-/Baa3	170.0	35.0
	BBB- or Baa3 (current)	130.0	30.0
	BBB or Baa2	110.0	20.0
	BBB+ or Baa1	100.0	15.0
	A- or A3 or higher	92.5	12.5
	The facility has a competitive bid feature, which allows the Company to solicit bids from lenders under the facility to borrow up to $300 million at interest rates less than those above.
	The terms of the unsecured facility include certain restrictions and covenants which limit, among other things the incurrence of additional indebtedness, the incurrence of liens and the disposition of real estate properties (to the extent that: (i) such property dispositions cause the Company to default on any of the financial ratios of the facility described below, or (ii) the property dispositions are completed while the Company is under an event of default under the facility, unless, under certain circumstances, such disposition is being carried out to cure such default), and which require compliance with financial ratios relating to the maximum leverage ratio (60 percent), the maximum amount of secured indebtedness (40 percent), the minimum amount of fixed charge coverage (1.5 times), the maximum amount of unsecured indebtedness (60 percent), the minimum amount of unencumbered property interest coverage (2.0 times) and certain investment limitations (generally 15 percent of total capitalization).    If an event of default has occurred and is continuing, the Company will not make any excess distributions except to enable the Company to continue to qualify as a REIT under the Code.  The Company was in compliance with its debt covenants under its revolving credit facility as of March 31, 2015.
	As of March 31, 2015, the Company had outstanding borrowings of $42 million under its unsecured revolving credit facility, and had no outstanding borrowings under the facility as of December 31, 2014.

Mortgages_Loans_Payable_And_Ot

Mortgages, Loans Payable And Other Obligations	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Mortgages, Loans Payable And Other Obligations	9.   MORTGAGES, LOANS PAYABLE AND OTHER OBLIGATIONS
	The Company has mortgages, loans payable and other obligations which primarily consist of various loans collateralized by certain of the Company’s rental properties.  As of March 31, 2015,  28 of the Company’s properties, with a total book value of approximately $968 million, are encumbered by the Company’s mortgages and loans payable.  Payments on mortgages, loans payable and other obligations are generally due in monthly installments of principal and interest, or interest only.  Except as noted below, the Company was in compliance with its debt covenants under its mortgages and loans payable as of March 31, 2015.
	A summary of the Company’s mortgages, loans payable and other obligations as of March 31, 2015 and December 31, 2014 is as follows: (dollars in thousands)
				Effective				March 31,		December 31,
	Property Name	Lender		Rate (a)				2015		2014		Maturity
	Overlook - Site IIID,IIIC, IIIA (b)	Wells Fargo Bank N.A.	LIBOR+3.50		%			-	$	17,260
	Overlook - Site IIB (Quarrystone I) (b)	Wells Fargo Bank N.A.	LIBOR+2.50		%			-		5,787
	6 Becker, 85 Livingston,	Wells Fargo CMBS		10.260	%		$	65,035		65,035		8/11/14	(d)
	75 Livingston &
	20 Waterview (c)
	4 Sylvan	Wells Fargo CMBS		10.260	%			14,575		14,575		8/11/14	(d)
	10 Independence	Wells Fargo CMBS		10.260	%			16,924		16,924		8/11/14	(d)
	9200 Edmonston Road (e)	Principal Commercial Funding L.L.C.		5.534	%			3,903		3,951		5/1/15
	Port Imperial South	Wells Fargo Bank N.A.	LIBOR+1.75		%			44,333		44,119		9/19/15
	4 Becker	Wells Fargo CMBS		9.550	%			39,568		39,421		5/11/16
	5 Becker (f)	Wells Fargo CMBS		19.450	%			14,073		13,867		5/11/16
	210 Clay  (g)	Wells Fargo CMBS		18.100	%			13,549		13,330		5/11/16
	Curtis Center (h)	CCRE & PREFG	LIBOR+5.912		%	(k)		64,000		64,000		10/9/16
	Various (i)	Prudential Insurance		6.332	%			145,058		145,557		1/15/17
	150 Main St.	Webster Bank	LIBOR+2.35		%			1,963		1,193	(m)	3/30/17
	23 Main Street	JPMorgan CMBS		5.587	%			29,041		29,210		9/1/18
	Harborside Plaza 5	The Northwestern Mutual Life		6.842	%			220,630		221,563		11/1/18
		Insurance Co. & New York Life
		Insurance Co.
	100 Walnut Avenue	Guardian Life Insurance Co.		7.311	%			18,476		18,542		2/1/19
	One River Center (j)	Guardian Life Insurance Co.		7.311	%			42,326		42,476		2/1/19
	Park Square	Wells Fargo Bank N.A.	LIBOR+1.872		%	(l)		27,500		27,500		4/10/19
	Port Imperial South 4/5 Retail	American General Life & A/G PC		4.559	%			4,000		4,000		12/1/21
	Port Imperial South 4/5 Garage	American General Life & A/G PC		4.853	%			32,600		32,600		12/1/29
	Total mortgages, loans payable and other obligations						$	797,554	$	820,910
	(a)	Reflects effective rate of debt, including deferred financing costs, comprised of the cost of terminated treasury lock agreements (if any), debt initiation costs, mark-to-market adjustment of acquired debt and other transaction costs, as applicable.
	(b)	On March 27, 2015, the Company repaid these loans at par, using borrowings on the Company's unsecured revolving credit facility.
	(c)	Mortgage is cross collateralized by the four properties.
	(d)	The loan was not repaid at maturity and the Company has begun discussions with the lender regarding a potential deed-in-lieu of foreclosure in satisfaction of the obligation.
	(e)	The mortgage loan originally matured on May 1, 2013.  The maturity date was extended until May 1, 2015 with the same interest rate.  Excess cash flow, as defined, is being held by the lender for re-leasing costs.  The deed for the property was placed in escrow and is available to the lender in the event of default or non-payment at maturity.
	(f)	The cash flow from this property is insufficient to cover operating costs and debt service.  Consequently, the Company notified the lender and suspended debt service payments in August 2013.  The Company has begun discussions with the lender regarding a deed-in-lieu of foreclosure and began remitting available cash flow to the lender effective August 2013.
	(g)	The cash flow from this property is insufficient to cover operating costs and debt service.  Consequently, the Company notified the lender and suspended debt service payments in January 2015.
	(h)	The Company owns a 50 percent tenants-in-common interest in the Curtis Center property.  The Company’s $64.0 million loan consists of its 50 percent interest in a $102 million senior loan with a current rate of 3.469 percent at March 31, 2015 and its 50 percent interest in a $26 million mezzanine loan (with a maximum borrowing capacity of $48 million) with a current rate of 9.675 percent at March 31, 2015.  The senior loan rate is based on a floating rate of one-month LIBOR plus 329 basis points and the mezzanine loan rate is based on a floating rate of one-month LIBOR plus 950 basis points.  The Company has entered into LIBOR caps for the periods of the loans.  The loans provide for three one-year extension options.
	(i)	Mortgage is cross collateralized by seven properties. The Company has agreed, subject to certain conditions, to guarantee repayment of a portion of the loan.
	(j)	Mortgage is collateralized by the three properties comprising One River Center.
	(k)	The effective interest rate includes amortization of deferred financing costs of 1.362 percent.
	(l)	The effective interest rate includes amortization of deferred financing costs of 0.122 percent.
	(m)	This construction loan has a maximum borrowing capacity of $28.8 million.
	CASH PAID FOR INTEREST AND INTEREST CAPITALIZED
	Cash paid for interest for the three months ended March 31, 2015 and 2014 was $25,922,000 and $36,119,000, respectively.  Interest capitalized by the Company for the three months ended March 31, 2015 and 2014 was $3,607,000 and $3,141,000, respectively (of which these amounts included $1,256,000 and $918,000 for the three months ended March 31, 2015 and 2014, respectively, for interest capitalized on the Company’s investments in unconsolidated joint ventures which were substantially in development).
	SUMMARY OF INDEBTEDNESS
	As of March 31, 2015, the Company’s total indebtedness of $2,107,572,000 (weighted average interest rate of 5.65 percent) was comprised of $179,795,000 of revolving credit facility borrowings and other variable rate mortgage debt (weighted average rate of 3.33 percent) and fixed rate debt and other obligations of $1,927,777,000 (weighted average rate of 5.87 percent).
	As of December 31, 2014, the Company’s total indebtedness of $2,088,654,000 (weighted average interest rate of 5.64 percent) was comprised of $159,860,000 of variable rate mortgage debt (weighted average rate of 3.83 percent) and fixed rate debt and other obligations of $1,928,794,000 (weighted average rate of 5.79 percent).

Employee_Benefit_401k_Plans_An

Employee Benefit 401(k) Plans And Deferred Retirement Compensation Agreements	3 Months Ended
	Mar. 31, 2015
Employee Benefit 401(k) Plans And Deferred Retirement Compensation Agreements [Abstract]
Employee Benefit 401(k) Plans And Deferred Retirement Compensation Agreements	10.  EMPLOYEE BENEFIT 401(k) PLANS AND DEFERRED RETIREMENT COMPENSATION AGREEMENTS
	Employees of the Company, who meet certain minimum age and service requirements, are eligible to participate in the Mack-Cali Realty Corporation 401(k) Savings/Retirement Plan (the “401(k) Plan”).  Eligible employees may elect to defer from one percent up to 60 percent of their annual compensation on a pre-tax basis to the 401(k) Plan, subject to certain limitations imposed by federal law.  The amounts contributed by employees are immediately vested and non-forfeitable.  The Company may make discretionary matching or profit sharing contributions to the 401(k) Plan on behalf of eligible participants in any plan year.  Participants are always 100 percent vested in their pre-tax contributions and will begin vesting in any matching or profit sharing contributions made on their behalf after two years of service with the Company at a rate of 20 percent per year, becoming 100 percent vested after a total of six years of service with the Company.  All contributions are allocated as a percentage of compensation of the eligible participants for the Plan year.  The assets of the 401(k) Plan are held in trust and a separate account is established for each participant.  A participant may receive a distribution of his or her vested account balance in the 401(k) Plan in a single sum or in installment payments upon his or her termination of service with the Company.  Total expense recognized by the Company for the 401(k) Plan for the three months ended March 31, 2015 and 2014 was zero and $25,000, respectively.
	On September 12, 2012, the Board of Directors of the Company approved multi-year deferred retirement compensation agreements for those executive officers in place on such date (the “Deferred Retirement Compensation Agreements”).  Pursuant to the Deferred Retirement Compensation Agreements, the Company was to make annual contributions of stock units (“Stock Units”) representing shares of the Company’s common stock on January 1 of each year from 2013 through 2017 into a deferred compensation account maintained on behalf of each participating executive.   Vesting of each annual contribution of Stock Units was to occur on December 31 of each year, subject to continued employment.  In connection with the separation from service to the Company of certain executive officers effective March 31, 2014, the Company agreed to make cash payments totaling $1.2 million for all vested and unvested Stock Units and future cash contributions pursuant to the Deferred Retirement Compensation Agreements.   In connection with the announcement on November 4, 2014 of the separation from service to the Company of its President and Chief Executive Officer effective May 11, 2015, the Company agreed to make cash payments of $2.3 million on the separation date for all vested and unvested Stock Units and future cash contributions pursuant to his Deferred Retirement Compensation Agreement.  Total expense recognized by the Company under the Deferred Retirement Compensation Agreements for the three months ended March 31, 2015 and 2014 was zero and $1.2 million, respectively.  See Note 12: Commitments and Contingencies – Departure of Executive Officers.

Disclosure_Of_Fair_Value_Of_Fi

Disclosure Of Fair Value Of Financial Instruments	3 Months Ended
	Mar. 31, 2015
Disclosure Of Fair Value Of Financial Instruments [Abstract]
Disclosure Of Fair Value Of Financial Instruments	11.  DISCLOSURE OF FAIR VALUE OF FINANCIAL INSTRUMENTS
	The following disclosure of estimated fair value was determined by management using available market information and appropriate valuation methodologies.  However, considerable judgment is necessary to interpret market data and develop estimated fair value.  Accordingly, the estimates presented herein are not necessarily indicative of the amounts the Company could realize on disposition of the financial instruments at March 31, 2015 and December 31, 2014.  The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts.
	Cash equivalents, receivables, notes receivables, accounts payable, and accrued expenses and other liabilities are carried at amounts which reasonably approximate their fair values as of March 31, 2015 and December 31, 2014.
	The fair value of the Company’s long-term debt, consisting of senior unsecured notes, an unsecured revolving credit facility and mortgages, loans payable and other obligations aggregated approximately $2,125,451,000 and $2,133,214,000 as compared to the book value of approximately $2,107,572,000 and $2,088,654,000 as of March 31, 2015 and December 31, 2014, respectively.  The fair value of the Company’s long-term debt was categorized as a level 3 basis (as provided by ASC 820, Fair Value Measurements and Disclosures).  The fair value was estimated using a discounted cash flow analysis valuation based on the borrowing rates currently available to the Company for loans with similar terms and maturities.  The fair value of the mortgage debt and the unsecured notes was determined by discounting the future contractual interest and principal payments by a market rate.  Although the Company has determined that the majority of the inputs used to value its derivative financial instruments fall within level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivative financial instruments utilize level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. The Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivative financial instruments. As a result, the Company has determined that its derivative financial instruments valuations in their entirety are classified in level 2 of the fair value hierarchy.
	Disclosure about fair value of financial instruments is based on pertinent information available to management as of March 31, 2015 and December 31, 2014.  Although management is not aware of any factors that would significantly affect the fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since March 31, 2015 and current estimates of fair value may differ significantly from the amounts presented herein.

Commitments_And_Contingencies

Commitments And Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments And Contingencies [Abstract]
Commitments And Contingencies	12.  COMMITMENTS AND CONTINGENCIES
	TAX ABATEMENT AGREEMENTS
	Pursuant to agreements with certain municipalities, the Company is required to make payments in lieu of property taxes (“PILOT”) on certain of its properties and has tax abatement agreements on other properties, as follows:
	The Harborside Plaza 4-A agreement with the City of Jersey City, as amended, which commenced in 2002, is for a term of 20 years.  The annual PILOT is equal to two percent of Total Project Costs, as defined.  Total Project Costs are $49.5 million.  The PILOT totaled $247,000 and $247,000 for the three months ended March 31, 2015 and 2014, respectively.
	The Harborside Plaza 5 agreement, also with the City of Jersey City, as amended, which commenced in 2002, is for a term of 20 years.  The annual PILOT is equal to two percent of Total Project Costs, as defined.  Total Project Costs are $170.9 million.  The PILOT totaled $854,000 and $854,000 for the three months ended March 31, 2015 and 2014, respectively.
	The agreement with the City of Weehawken for its Port Imperial 4/5 garage development project (acquired in the Roseland Transaction) was executed in March 2011 and has a term of five years beginning when the project is substantially complete, which occurred in the third quarter 2013.  The agreement provides that real estate taxes be paid initially on the land value of the project only and allows for a phase in of real estate taxes on the value of the improvements over a five year period.
	The agreement with the City of Rahway for its Park Square multi-family rental property executed in 2009 provides that real estate taxes will be partially abated, on a declining scale, for four years from 2011 through 2015.
	At the conclusion of the above-referenced agreements, it is expected that the properties will be assessed by the municipality and be subject to real estate taxes at the then prevailing rates.
	LITIGATION
	The Company is a defendant in litigation arising in the normal course of its business activities.  Management does not believe that the ultimate resolution of these matters will have a materially adverse effect upon the Company’s financial condition taken as whole.
	GROUND LEASE AGREEMENTS
	Future minimum rental payments under the terms of all non-cancelable ground leases under which the Company is the lessee, as of March 31, 2015, are as follows: (dollars in thousands)
	Year		Amount
	April 1 through December 31, 2015	$	278
	2016		371
	2017		267
	2018		232
	2019		235
	2020 through 2084		15,584
	Total	$	16,967
	Ground lease expense incurred by the Company during the three months ended March 31, 2015 and 2014 amounted to $102,000 and $102,000, respectively.
	ROSELAND CONTINGENT CONSIDERATION
	The purchase price for the Roseland Transaction included the fair value of contingent consideration pursuant to an earn-out (“Earn Out”) agreement of approximately $10 million.  Since the acquisition, the Company recognized benefits related to a decline in  fair value in the Earn Out liability and, as a result of the achievement of certain of the defined criteria, paid certain amounts such that the balance of the Earn Out as of March 31, 2015 was $0.9 million.  Prospectively, the Earn Out liability will be remeasured at fair value quarterly until the contingency has been resolved, with any changes in fair value representing a charge or benefit directly to earnings (with no adjustment to purchase accounting).  The measures of the Earn Out are based on significant inputs that are not observable in the market, which ASC 820 refers to as level 3 inputs.  In addition to an appropriate discount rate, the key assumption affecting the valuation for the Roseland Assets component was the probability of occurrence of the payment events under the relevant provisions (management assumed between 92 and 99 percent for completion/start criteria and 50 percent for the tax credit/grant criteria in its initial valuation).  The valuation of the TRS component includes assumptions for the risk-free rate and various other factors (i.e., stock price, dividend levels and volatility) for the Company and the relevant peer group, as defined in the Earn Out agreement.
	DEPARTURE OF EXECUTIVE OFFICERS
	On March 3, 2014, the Company announced that Barry Lefkowitz was leaving his position as Executive Vice President and Chief Financial Officer of the Company effective March 31, 2014.  In connection with Mr. Lefkowitz’s departure, he received severance benefits payable pursuant to his employment agreement and outstanding equity compensation awards, including an aggregate cash payment of approximately $3.4 million, vesting of 11,457 newly issued shares of common stock of the Company, and vesting of 68,667 unvested shares of Restricted Stock Awards. The Company also will pay the premiums for the continuation of Mr. Lefkowitz’s existing health insurance for a period up to 48 months following March 31, 2014.
	Also on March 3, 2014, the Company announced that Roger W. Thomas was leaving his position as Executive Vice President, General Counsel and Secretary of the Company effective March 31, 2014.  In connection with Mr. Thomas’ departure, he received severance benefits payable pursuant to his employment agreement and outstanding equity compensation awards, including an aggregate cash payment of approximately $3.1 million, acceleration and discretionary full vesting of 33,605 newly issued shares of common stock of the Company, and vesting of 41,000 unvested shares of Restricted Stock Awards. The Company also will pay the premiums for the continuation of Mr. Thomas’ existing health insurance for a period of up to 48 months following September 30, 2014. Mr. Thomas served as a consultant to the Company from April 1, 2014 through September 30, 2014 for an aggregate cash compensation of $300,000.
	On November 4, 2014, the Company announced that Mitchell E. Hersh will step down as President and Chief Executive Officer of the Company effective May 11, 2015 (the “Separation Date”) and will not stand for re-election to the Company’s Board of Directors (the “Board of Directors”) at the 2015 annual meeting of the Company’s stockholders. In connection with Mr. Hersh’s departure from the Company, the Company and Mr. Hersh entered into a Separation and General Release Agreement (the “Separation Agreement”) dated November 4, 2014 (the “Effective Date”). The Separation Agreement provides that Mr. Hersh’s employment with the Company is being terminated without cause, and further provides, pursuant to the terms of Mr. Hersh’s employment agreement, multi-year performance award agreement, TSR-based performance award agreement and deferred retirement compensation agreement, for (i) a cash payment to Mr. Hersh of $8 million, (ii) payment of the premiums for the continuation of Mr. Hersh’s health, dental and vision insurance for 48 months following the Separation Date, (iii) vesting of 210,000 shares of restricted common stock pursuant to Mr. Hersh’s multi-year performance award agreement, (iv) a cash payment equal to the sum of (X) $504,000, plus (Y) the product of (1) 210,000 multiplied by (2) the aggregate amount of dividends on the Company’s common stock that are declared and paid between the Effective Date and the Separation Date in payment of accrued but unpaid dividend equivalents pursuant to his multi-year performance award agreement, (v) issuance of 41,811 shares of common stock of the Company (the “Deferred Shares”) pursuant to the acceleration of vesting of 675 performance shares pursuant to Mr. Hersh’s TSR-based performance award agreement, and (vi) a cash payment of $2,311,792 pursuant to Mr. Hersh’s deferred retirement compensation award agreement. All such cash amounts and Deferred Shares will be paid to Mr. Hersh on the date that is six months and one day from the Separation Date, except in the event of death or if the payment event is due to Mr. Hersh’s disability, in which case the payments will occur shortly after such death or disability. Under the terms of the Separation Agreement, Mr. Hersh will continue to receive his base salary in accordance with his employment agreement and will continue to be eligible to participate in the Company’s executive incentive compensation and bonus programs. In addition, upon departure Mr. Hersh will also be entitled to receive his accrued but unpaid base salary and to have his expenses reimbursed. The Separation Agreement provides that the Separation Date may be extended at the election of the Company to June 30, 2015 or accelerated by Mr. Hersh for good reason, as such term is defined in the Separation Agreement.
	The Company’s total estimated costs for the pending departure of the Company’s President and Chief Executive Officer and of the departure of certain of the Company’s executive officers of approximately $23.8 million during the year ended December 31, 2014, of which approximately $11 million was recognized during the three months ended March 31, 2014,  was included in general and administrative expense (approximately $11.6 million was included in accounts payable, accrued expenses and other liabilities as of both March 31, 2015 and December 31, 2014).
	ROSELAND TRANSACTION MODIFICATIONS
	On July 18, 2014, the Company entered into separation agreements (the “Roseland Separation Agreements”) with each of Bradford R. Klatt and Carl Goldberg, formerly principals of Roseland Partners who have served as co-presidents of Roseland Management since the Company acquired the Roseland Business in October 2012.  The Roseland Separation Agreements provide that the employment agreements of Messrs. Klatt and Goldberg terminate and that they shall resign as co-presidents of Roseland Management effective October 23, 2014 (the “Roseland Separation Date”).  Also on July 18, 2014, the Company amended its purchase agreement with the sellers of the Roseland Business (the “Roseland Amendment”) to modify certain terms of the Roseland Transaction in connection with the departures of Messrs. Klatt and Goldberg.  In addition, Mr. Goldberg entered into a consulting agreement with Roseland Management (the “Consulting Agreement”) pursuant to which he shall provide consulting services for a period of one year following the Separation Date for $400,000 payable in four, equal quarterly installments.
	Pursuant to the Roseland Separation Agreements, each of Messrs. Klatt and Goldberg received a separation payment of $750,000 within five days following the Roseland Separation Date, and shall receive an additional payment of $500,000 in full satisfaction of any and all bonus payments under their respective employment agreements, which amount shall be paid six months after the date of their “separation from service” as defined in Section 409A of the Internal Revenue Code of 1986, as amended, and the Treasury Regulations and other guidance promulgated thereunder.  The Roseland Separation Agreements also contain customary mutual releases of claims and non-disparagement provisions, and Mr. Goldberg’s Consulting Agreement contains customary non-compete, confidentiality and indemnification covenants.  Mr. Goldberg’s Separation Agreement also provides that Roseland Management shall pay the premiums for the continuation of his existing health insurance for a period of one year from the Roseland Separation Date or until any earlier termination of his Consulting Agreement.
	The Roseland Amendment provides for the following material modifications to the Roseland Transaction:
	1.The non-competition covenants as they apply to Messrs. Klatt and Goldberg shall terminate on the Roseland Separation Date, and the non-competition covenants as they apply to Marshall Tycher shall be amended to permit Mr. Tycher to invest in certain future, family-controlled business ventures, subject to a right of first offer by the Company to make an investment of at least 50 percent in multi-family properties or projects covered by the right of first offer;
	2.The release to the sellers of the Roseland Business of all remaining funds held in the indemnity escrow account and the acceleration of the effectiveness of certain indemnity covenants to the Roseland Separation Date; and
	3.The payment of $1 million of the $3 million Earn Out related to certain tax credits/grants.
	Included in accounts payable, accrued expense and other liabilities as of March 31, 2015 and December 31, 2014 was $1.0 million related to the Roseland Separation Agreements and Roseland Amendment.
	OTHER
	The Company may not dispose of or distribute certain of its properties, currently comprised of seven properties with an aggregate net book value of approximately $124.6 million, which were originally contributed by certain unrelated common unitholders, without the express written consent of such common unitholders, as applicable, except in a manner which does not result in recognition of any built-in-gain (which may result in an income tax liability) or which reimburses the appropriate specific common unitholders for the tax consequences of the recognition of such built-in-gains (collectively, the “Property Lock-Ups”).  The aforementioned restrictions do not apply in the event that the Company sells all of its properties or in connection with a sale transaction which the Company’s Board of Directors determines is reasonably necessary to satisfy a material monetary default on any unsecured debt, judgment or liability of the Company or to cure any material monetary default on any mortgage secured by a property.  The Property Lock-Ups expire periodically through 2016.  Upon the expiration of the Property Lock-Ups, the Company is generally required to use commercially reasonable efforts to prevent any sale, transfer or other disposition of the subject properties from resulting in the recognition of built-in gain to the specific common unitholders, which include members of the Mack Group (which includes William L. Mack, Chairman of the Company’s Board of Directors; David S. Mack, director; Earle I. Mack, a former director; and Mitchell E. Hersh, president, chief executive officer and director), the Robert Martin Group (which includes Robert F. Weinberg, a former director and current member of its Advisory Board), and the Cali Group (which includes John R. Cali, a former director and current member of its Advisory Board).  110 of the Company’s properties, with an aggregate net book value of approximately $1.3 billion, have lapsed restrictions and are subject to these conditions.
	On May 21, 2014, the Company entered into a joint venture agreement with Ironstate Harborside-A LLC (“ISA”) to form Harborside Unit A Urban Renewal, L.L.C. (“URL-Harborside”), a newly-formed joint venture that will develop, own and operate a high-rise tower of approximately 763 multi-family apartment units above a parking pedestal to be located on land contributed by the Company at its Harborside complex in Jersey City, New Jersey (the “URL Project”).  The Company owns an 85 percent interest in URL-Harborside and the remaining interest is owned by ISA, with shared control over major decisions such as approval of budgets, property financings and leasing guidelines.  The construction of the URL Project is estimated to cost a total of approximately $320 million (of which development costs of $88.8 million have been incurred by URL-Harborside through March 31, 2015).  The URL Project is projected to be ready for occupancy by the fourth quarter of 2016.  The venture has a construction/permanent loan with a maximum borrowing amount of $192 million (with no balance currently outstanding as of March 31, 2015), which bears interest at a rate of 5.197 percent and matures in August 2029.  The Company currently expects that it will fund approximately $42.2 million of the remaining development costs of the project, net of the loan financing.
	In July 2012, the Company entered into a ground lease with Wegmans Food Markets, Inc. (“Wegmans”) at the Company’s undeveloped site located at Sylvan Way and Ridgedale Avenue in Hanover Township, New Jersey.  Subject to receiving all necessary governmental approvals, Wegmans intends to construct a store of approximately 140,000 square feet on a finished pad scheduled to be completed in late 2016.  The Company expects to incur costs of approximately $25.3 million for the development of the site (of which the Company has incurred $9.3 million through March 31, 2015).
	The Company owns a 76.25 percent interest in a consolidated joint venture which is constructing a 108-unit multi-family development rental property located in Eastchester, New York (the “Eastchester Project”).  The project is expected to be ready for occupancy by the second quarter of 2016.  The Eastchester Project is estimated to cost a total of $50 million (of which development costs of $15.4 million have been incurred through March 31, 2015).  The venture has a $28.8 million construction loan (with $2.0 million outstanding as of March 31, 2015).  The Company expects to fund $20.9 million of the remaining development costs balance.
	On April 1, 2015, the Company acquired vacant land to accommodate the development of the CitySquare Project for a purchase price of $3.1 million with an additional $1.25 million to be paid, subject to certain conditions, in accordance with the terms of the purchase and sale agreement.  The purchase price for the acquisition was funded primarily through borrowing under the Company’s unsecured revolving credit facility.  The Company is required to begin construction of the CitySquare Project within 12 months of closing.  The Company plans to start construction in the third quarter 2015 and the total development costs are estimated to be approximately $88 million.

Tenant_Leases

Tenant Leases	3 Months Ended
	Mar. 31, 2015
Tenant Leases [Abstract]
Tenant Leases	13.  TENANT LEASES
	The Properties are leased to tenants under operating leases with various expiration dates through 2035.  Substantially all of the commercial leases provide for annual base rents plus recoveries and escalation charges based upon the tenant’s proportionate share of and/or increases in real estate taxes and certain operating costs, as defined, and the pass‑through of charges for electrical usage.
	Future minimum rentals to be received under non-cancelable commercial operating leases at March 31, 2015 are as follows (dollars in thousands):
	Year		Amount
	April 1 through December 31, 2015	$	342,120
	2016		432,644
	2017		381,749
	2018		301,126
	2019		245,082
	2020 and thereafter		982,973
	Total	$	2,685,694
	Multi-family rental property residential leases are excluded from the above table as they generally expire within one year.

MackCali_Realty_Corporation_St

Mack-Cali Realty Corporation Stockholders' Equity	3 Months Ended
	Mar. 31, 2015
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]
Mack-Cali Realty Corporation Stockholders' Equity	14.  MACK-CALI REALTY CORPORATION STOCKHOLDERS’ EQUITY
	To maintain its qualification as a REIT, not more than 50 percent in value of the outstanding shares of the Company may be owned, directly or indirectly, by five or fewer individuals at any time during the last half of any taxable year of the Company, other than its initial taxable year (defined to include certain entities), applying certain constructive ownership rules.  To help ensure that the Company will not fail this test, the Company’s Charter provides, among other things, certain restrictions on the transfer of common stock to prevent further concentration of stock ownership.  Moreover, to evidence compliance with these requirements, the Company must maintain records that disclose the actual ownership of its outstanding common stock and demands written statements each year from the holders of record of designated percentages of its common stock requesting the disclosure of the beneficial owners of such common stock.
	SHARE REPURCHASE PROGRAM
	In September 2012, the Board of Directors renewed and authorized an increase to the Company’s repurchase program (“Repurchase Program”).  The Company has authorization to repurchase up to $150 million of its outstanding common stock under the renewed Repurchase Program, which it may repurchase from time to time in open market transactions at prevailing prices or through privately negotiated transactions.  The Company has purchased and retired 394,625 shares of its outstanding common stock for an aggregate cost of approximately $11 million (all of which occurred in the year ended December 31, 2012), with a remaining authorization under the Repurchase Program of $139 million.
	DIVIDEND REINVESTMENT AND STOCK PURCHASE PLAN
	The Company has a Dividend Reinvestment and Stock Purchase Plan (the “DRIP”) which commenced in March 1999 under which approximately 5.5 million shares of the Company’s common stock have been reserved for future issuance.  The DRIP provides for automatic reinvestment of all or a portion of a participant’s dividends from the Company’s shares of common stock.  The DRIP also permits participants to make optional cash investments up to $5,000 a month without restriction and, if the Company waives this limit, for additional amounts subject to certain restrictions and other conditions set forth in the DRIP prospectus filed as part of the Company’s effective registration statement on Form S-3 filed with the SEC for the approximately 5.5 million shares of the Company’s common stock reserved for issuance under the DRIP.
	STOCK OPTION PLANS
	In May 2013, the Company established the 2013 Incentive Stock Plan (the “2013 Plan”) under which a total of 4,600,000 shares have been reserved for issuance.  In May 2004, the Company established the 2004 Incentive Stock Plan (the “2004 Plan”) under which a total of 2,500,000 shares had been reserved for issuance.  The 2004 Plan was terminated upon establishment of the 2013 Plan.  No options were granted under the 2004 Plan.  In September 2000, the Company established the 2000 Employee Stock Option Plan (“2000 Employee Plan”) and the Amended and Restated 2000 Director Stock Option Plan (“2000 Director Plan” and together with the 2000 Employee Plan, the “2000 Plans”).  In May 2002, shareholders of the Company approved amendments to both of the 2000 Plans to increase the total shares reserved for issuance under both of the 2000 Plans from 2,700,000 to 4,350,000 shares of the Company’s common stock (from 2,500,000 to 4,000,000 shares under the 2000 Employee Plan and from 200,000 to 350,000 shares under the 2000 Director Plan).  As the 2000 Plans expired in 2010, stock options may no longer be issued under those plans.  Stock options granted under the 2000 Employee Plan became exercisable over a five-year period.  All stock options granted under the 2000 Director Plan became exercisable in one year.  All options were granted at the fair market value at the dates of grant and have terms of 10 years.  As of March 31, 2015 and December 31, 2014, the stock options outstanding had a weighted average remaining contractual life of approximately 4.7 and 4.9 years, respectively.
	Information regarding the Company’s stock option plans is summarized below:
					Weighted		Aggregate
					Average		Intrinsic
		Shares			Exercise		Value
		Under Options			Price		$(000’s)
	Outstanding at January 1, 2015	10,000		$	33.36		-
	Granted, lapsed or cancelled	-			-
	Outstanding at March 31, 2015  ($21.25 – $45.47)	10,000		$	33.36		-
	Options exercisable at March 31, 2015	5,000
	Available for grant at March 31, 2015	4,420,227
	There were no stock options exercised under all stock option plans for the three months ended March 31, 2015 and 2014, respectively.  The Company has a policy of issuing new shares to satisfy stock option exercises.
	The Company recognized stock options expense of $1,000 and $1,000 for the three months ended March 31, 2015 and 2014, respectively.
	RESTRICTED STOCK AWARDS
	The Company has issued stock awards (“Restricted Stock Awards”) to officers, certain other employees, and nonemployee members of the Board of Directors of the Company, which allow the holders to each receive a certain amount of shares of the Company’s common stock generally over a one to seven-year vesting period, of which 313,337 unvested shares were legally outstanding at March 31, 2015.  Of the Restricted Stock Awards issued to executive officers and certain other employees, 210,000 were contingent upon the Company meeting certain performance goals to be set by the Executive Compensation and Option Committee of the Board of Directors of the Company each year (“Performance Shares”), with the remaining based on time and service.  All currently outstanding and unvested Restricted Stock Awards provided to the officers and certain other employees were issued under the 2013 Plan and 2004 Plan.  Currently outstanding and unvested Restricted Stock Awards provided to directors were issued under the 2013 Plan.
	On September 12, 2012, the Board of Directors of the Company approved the recommendations and ratified the determinations of the Executive Compensation and Option Committee of the Board of Directors (the “Committee”) with respect to new Restricted Stock Awards totaling 319,667 shares for those executive officers in place on such date.  The new Restricted Stock Awards were to vest commencing January 1, 2014 and with the number of Restricted Stock Awards scheduled to be vested and earned on each vesting date on an annual basis over a five to seven year vesting schedule, with each annual vesting of each tranche of Restricted Stock Awards being subject to the attainment of annual performance targets to be set by the Committee for each year.  In connection with the departure of two executive officers effective March 31, 2014, the Company agreed to grant and accelerate vesting of 109,667 shares of Restricted Stock Awards on April 1, 2014.  In connection with the announcement of the departure of the Company’s President and Chief Executive Officer effective May 11, 2015, the Company agreed to vest 84,000 Performance Shares and to grant and accelerate the vesting of 126,000 Performance Shares on the Separation Date.  See Note 12: Commitments and Contingencies – Departure of Executive Officers.
	Information regarding the Restricted Stock Awards grant activity is summarized below:
					Weighted-Average
					Grant – Date
		Shares			Fair Value
	Outstanding at January 1, 2015	346,946		$	21.09
	Granted	3,786			19.53
	Vested	-37,392			21.59
	Forfeited	-3			26.36
	Outstanding at March 31, 2015	313,337		$	21.01
	As of March 31, 2015, the Company had $1.2 million of total unrecognized compensation cost related to unvested Restricted Stock Awards granted under the Company’s stock compensation plans.  That cost is expected to be recognized over a weighted average period of 1.3 years.
	TSR-BASED AWARDS
	Also on September 12, 2012, the Board of Directors of the Company approved the recommendations and ratified the determinations of the Committee with respect to new multi-year TSR based awards (the “TSR-Based Awards”) totaling 5,160 performance shares (the “TSR Performance Shares”) for those executive officers in place on such date, each TSR Performance Share evidencing the right to receive $1,000 in the Company’s common stock upon vesting.  In accordance with the amended and restated TSR-Based Awards agreements entered into between the Company and those executive officers in June 2013, the TSR Performance Shares were to vest commencing December 31, 2014, with the number of TSR Performance Shares scheduled to be granted annually over the next four years.  The Company granted 1,032 TSR Performance Shares in the year ended December 31, 2013, which were valued in accordance with ASC 718, Compensation - Stock Compensation, at their fair value, utilizing a Monte-Carlo simulation to estimate the probability of the vesting conditions being satisfied.  The Company has reserved shares of common stock under the 2004 Plan for issuance upon vesting of the TSR Performance Shares in accordance with the terms and conditions of the TSR-Based Awards.  In connection with the departure of two executive officers effective March 31, 2014, the Company agreed to vest 357 TSR Performance Shares and to grant and accelerate the vesting of 528 TSR Performance Shares, for which the Company issued 45,062 shares of Common Stock on April 2, 2014.  In connection with the announcement of the departure of the Company’s President and Chief Executive Officer effective May 11, 2015, the Company agreed to vest 675 TSR Performance Shares on the Separation Date, when it would issue 41,811 shares of common stock.  See Note 12: Commitments and Contingencies – Departure of Executive Officers.
	DEFERRED STOCK COMPENSATION PLAN FOR DIRECTORS
	The Amended and Restated Deferred Compensation Plan for Directors, which commenced January 1, 1999, allows non‑employee directors of the Company to elect to defer up to 100 percent of their annual retainer fee into deferred stock units.  The deferred stock units are convertible into an equal number of shares of common stock upon the directors’ termination of service from the Board of Directors or a change in control of the Company, as defined in the plan.  Deferred stock units are credited to each director quarterly using the closing price of the Company’s common stock on the applicable dividend record date for the respective quarter.  Each participating director’s account is also credited for an equivalent amount of deferred stock units based on the dividend rate for each quarter.
	During the three months ended March 31, 2015 and 2014,  5,002 and 5,707 deferred stock units were earned, respectively.  As of March 31, 2015 and December 31, 2014, there were 162,761 and 157,730 deferred stock units outstanding, respectively.
	EARNINGS PER SHARE
	Basic EPS excludes dilution and is computed by dividing net income available to common shareholders by the weighted average number of shares outstanding for the period.  Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock.
	The following information presents the Company’s results for the three months ended March 31, 2015 and 2014 in accordance with ASC 260, Earnings Per Share: (dollars in thousands, except per share amounts)
			Three Months Ended
			March 31,
	Computation of Basic EPS		2015			2014
	Net loss	$	-3,325		$	-17,628
	Add: Noncontrolling interest in consolidated joint ventures		490			322
	Add:  Noncontrolling interest in Operating Partnership		314			2,008
	Net loss available to common shareholders	$	-2,521		$	-15,298
	Weighted average common shares		89,192			88,289
	Basic EPS:
	Net loss available to common shareholders	$	-0.03		$	-0.17
			Three Months Ended
			March 31,
	Computation of Diluted EPS		2015			2014
	Net loss available to common shareholders	$	-2,521		$	-15,298
	Add (deduct): Noncontrolling interest in Operating Partnership		-314			-2,008
	Net loss for diluted earnings per share	$	-2,835		$	-17,306
	Weighted average common shares		100,266			99,876
	Diluted EPS:
	Net loss available to common shareholders	$	-0.03		$	-0.17
	The following schedule reconciles the shares used in the basic EPS calculation to the shares used in the diluted EPS calculation: (in thousands)
		Three Months Ended
		March 31,
		2015	2014
Basic EPS shares	89,192	88,289
Add:   Operating Partnership – common units	11,074	11,587
Diluted EPS Shares	100,266	99,876
Contingently issuable shares under the TSR Award plan were excluded from the denominator in 2014 because they were anti-dilutive for the period ended March 31, 2014.  Not included in the computations of diluted EPS were 10,000 and 15,000 stock options as such securities were anti-dilutive during the periods ended March 31, 2015 and 2014, respectively.  Unvested restricted stock outstanding as of March 31, 2015 and 2014 were 103,337 and 414,483 shares, respectively.
Dividends declared per common share for the three month periods ended March 31, 2015 and 2014 was $0.15 and $0.30 per share, respectively.

Noncontrolling_Interests_In_Su

Noncontrolling Interests In Subsidiaries	3 Months Ended
	Mar. 31, 2015
Noncontrolling Interests In Subsidiaries [Abstract]
Noncontrolling Interests In Subsidiaries	15.   NONCONTROLLING INTERESTS IN SUBSIDIARIES
	Noncontrolling interests in subsidiaries in the accompanying consolidated financial statements relate to (i) common units in the Operating Partnership, held by parties other than the Company, and (ii) interests in consolidated joint ventures for the portion of such ventures not owned by the Company.
	OPERATING PARTNERSHIP
	Common Units
	Certain individuals and entities own common units in the Operating Partnership.  A common unit and a share of Common Stock of the Company have substantially the same economic characteristics in as much as they effectively share equally in the net income or loss of the Operating Partnership.  Common unitholders have the right to redeem their common units, subject to certain restrictions.  The redemption is required to be satisfied in shares of Common Stock, cash, or a combination thereof, calculated as follows:  one share of the Company’s Common Stock, or cash equal to the fair market value of a share of the Company’s Common Stock at the time of redemption, for each common unit.  The Company, in its sole discretion, determines the form of redemption of common units (i.e., whether a common unitholder receives Common Stock, cash, or any combination thereof).  If the Company elects to satisfy the redemption with shares of Common Stock as opposed to cash, it is obligated to issue shares of its Common Stock to the redeeming unitholder.  Regardless of the rights described above, the common unitholders may not put their units for cash to the Company or the Operating Partnership under any circumstances.  When a unitholder redeems a common unit, noncontrolling interest in the Operating Partnership is reduced and Mack-Cali Realty Corporation Stockholders’ equity is increased.
	Unit Transactions
	The following table sets forth the changes in noncontrolling interests in subsidiaries which relate to the common units in the Operating Partnership for the three months ended March 31, 2015:
		Common
		Units
	Balance at January 1, 2015	11,083,876
	Redemption of common units for shares of common stock	-46,978
	Balance at March 31, 2015	11,036,898
	The following table reflects the activity of noncontrolling interests for the three months ended March 31, 2015 and 2014, respectively (dollars in thousands):
			Three Months Ended
			March 31,
			2015		2014
	Balance at January 1	$	257,230	$	276,096
	Net loss		-804		-2,330
	Common unit distributions		-1,656		-3,455
	Increase in noncontrolling interests in consolidated joint ventures		94		-
	Redemption of common units
	for common stock		-857		-6,452
	Rebalancing of ownership percentage
	between parent and subsidiaries		45		-21
	Balance at March 31	$	254,052	$	263,838
	Pursuant to ASC 810, Consolidation, on the accounting and reporting for noncontrolling interests and changes in ownership interests of a subsidiary, changes in a parent’s ownership interest (and transactions with noncontrolling interest unitholders in the subsidiary) while the parent retains its controlling interest in its subsidiary should be accounted for as equity transactions.  The carrying amount of the noncontrolling interest shall be adjusted to reflect the change in its ownership interest in the subsidiary, with the offset to equity attributable to the parent.  Accordingly, as a result of equity transactions which caused changes in ownership percentages between Mack-Cali Realty Corporation stockholders’ equity and noncontrolling interests in the Operating Partnership that occurred during the three months ended March 31, 2015, the Company has increased noncontrolling interests in the Operating Partnership and decreased additional paid-in capital in Mack-Cali Realty Corporation stockholders’ equity by approximately $45,000 as of March 31, 2015.
	Noncontrolling Interest Ownership
	As of March 31, 2015 and December 31, 2014, the noncontrolling interest common unitholders owned 11.0 percent and 11.1 percent of the Operating Partnership, respectively.
	CONSOLIDATED JOINT VENTURES
	The Company consolidates certain joint ventures in which it has ownership interests.  Various entities and/or individuals hold noncontrolling interests in these ventures.
	PARTICIPATION RIGHTS
	The Company’s interests in certain real estate projects (three properties and a future development) each provide for the initial distributions of net cash flow solely to the Company, and thereafter, other parties have participation rights (“Participation Rights”) in 50 percent of the excess net cash flow remaining after the distribution to the Company of the aggregate amount equal to the sum of: (a) the Company’s capital contributions, plus (b) an IRR of 10 percent per annum.

Segment_Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Reporting	16.   SEGMENT REPORTING
	The Company operates in three business segments: (i) commercial and other real estate, (ii) multi-family real estate, and (iii) multi-family services.  The Company provides leasing, property management, acquisition, development, construction and tenant-related services for its commercial and other real estate and multi-family real estate portfolio.  The Company’s multi‑family services business also provides similar services for third parties.  The Company no longer considers construction services as a reportable segment as it phased out this line of business in 2014.  The Company had no revenues from foreign countries recorded for the three months ended March 31, 2015 and 2014.  The Company had no long lived assets in foreign locations as of March 31, 2015 and December 31, 2014.  The accounting policies of the segments are the same as those described in Note 2: Significant Accounting Policies, excluding depreciation and amortization.
	The Company evaluates performance based upon net operating income from the combined properties in each of its real estate segments (commercial and other, and multi-family) and from its multi-family services segment.
	Selected results of operations for the three months ended March 31, 2015 and 2014 and selected asset information as of March 31, 2015 and December 31, 2014 regarding the Company’s operating segments are as follows.  Amounts for prior periods have been restated to conform to the current period segment reporting presentation: (dollars in thousands)
			Real Estate
			Commercial				Multi-family			Corporate		Total
			& Other		Multi-family		Services			& Other (d)		Company
	Total revenues:
	Three months ended:
	31-Mar-15	$	139,759	$	6,584	$	8,232	(e)	$	-860	$	153,715
	31-Mar-14		157,520		5,801		6,948	(f)		-673		169,596
	Total operating and
	interest expenses (a):
	Three months ended:
	31-Mar-15	$	72,198	$	3,321	$	9,655		$	27,679	$	112,853
	31-Mar-14		86,933		2,701		10,159			41,211		141,004
	Equity in earnings (loss) of
	unconsolidated joint ventures:
	Three months ended:
	31-Mar-15	$	-1,368	$	-2,161	$	-		$	-	$	-3,529
	31-Mar-14		988		-2,223		-			-		-1,235
	Net operating income (loss) (b):
	Three months ended:
	31-Mar-15	$	66,193	$	1,102	$	-1,423		$	-28,539	$	37,333
	31-Mar-14		71,575		877		-3,211			-41,884		27,357
	Total assets:
	31-Mar-15	$	3,627,443	$	515,643	$	11,154		$	44,614	$	4,198,854
	31-Dec-14		3,636,126		492,362		11,158			52,601		4,192,247
	Total long-lived assets (c):
	31-Mar-15	$	3,336,340	$	321,295	$	3,811		$	3,004	$	3,664,450
	31-Dec-14		3,344,840		318,524		3,858			3,482		3,670,704
	Total investments in
	unconsolidated joint ventures:
	31-Mar-15	$	79,094	$	182,554	$	404		$	-	$	262,052
	31-Dec-14		81,649		164,912		907			-		247,468
	(a)Total operating and interest expenses represent the sum of: real estate taxes; utilities; operating services; direct construction costs; real estate services expenses; general and administrative and interest expense (net of interest income).  All interest expense, net of interest and other investment income, (including for property-level mortgages) is excluded from segment amounts and classified in Corporate & Other for all periods.
	(b)Net operating income represents total revenues less total operating and interest expenses (as defined in Note “a”), plus equity in earnings (loss) of unconsolidated joint ventures, for the period.
	(c)Long-lived assets are comprised of net investment in rental property, unbilled rents receivable and goodwill.
	(d)Corporate & Other represents all corporate-level items (including interest and other investment income, interest expense, non-property general and administrative expense, construction services revenue and direct construction costs) as well as intercompany eliminations necessary to reconcile to consolidated Company totals.
	(e)Includes $1.3 million of fees earned for this period from the multi-family real estate segment, which are eliminated in consolidation.
	(f)Includes $0.8 million of fees earned for this period from the multi-family real estate segment, which are eliminated in consolidation.
	The following schedule reconciles net operating income to net income available to common shareholders: (dollars in thousands)
			Three Months Ended
			March 31,
			2015		2014
	Net operating income	$	37,333	$	27,357
	Add (deduct):
	Depreciation and amortization		-40,802		-44,985
	Realized gains on disposition of
	rental property, net		144		-
	Net loss		-3,325		-17,628
	Noncontrolling interest in consolidated joint ventures		490		322
	Noncontrolling interest in Operating Partnership		314		2,008
	Net loss available to common shareholders	$	-2,521	$	-15,298

Significant_Accounting_Policie1

Significant Accounting Policies (Policy)	3 Months Ended
	Mar. 31, 2015
Significant Accounting Policies [Abstract]
Rental Property	Rental
	PropertyRental properties are stated at cost less accumulated depreciation and amortization.  Costs directly related to the acquisition, development and construction of rental properties are capitalized.  Acquisition–related costs are expensed as incurred.  Capitalized development and construction costs include pre-construction costs essential to the development of the property, development and construction costs, interest, property taxes, insurance, salaries and other project costs incurred during the period of development.  Capitalized development and construction salaries and related costs approximated $1.3 million and $0.9 million for the three months ended March 31, 2015 and 2014, respectively.  Included in total rental property is construction, tenant improvement and development in-progress of $67.9 million and $62.8 million as of March 31, 2015 and December 31, 2014, respectively.  Ordinary repairs and maintenance are expensed as incurred; major replacements and betterments, which improve or extend the life of the asset, are capitalized and depreciated over their estimated useful lives.  Fully-depreciated assets are removed from the accounts.
	The Company considers a construction project as substantially completed and held available for occupancy upon the substantial completion of tenant improvements, but no later than one year from cessation of major construction activity (as distinguished from activities such as routine maintenance and cleanup).  If portions of a rental project are substantially completed and occupied by tenants, or held available for occupancy, and other portions have not yet reached that stage, the substantially completed portions are accounted for as a separate project.  The Company allocates costs incurred between the portions under construction and the portions substantially completed and held available for occupancy, primarily based on a percentage of the relative square footage of each portion, and capitalizes only those costs associated with the portion under construction.
	Properties are depreciated using the straight-line method over the estimated useful lives of the assets.  The estimated useful lives are as follows:
	Leasehold interests	Remaining lease term
	Buildings and improvements	5 to 40 years
	Tenant improvements	The shorter of the term of the
		related lease or useful life
	Furniture, fixtures and equipment	5 to 10 years
	Upon acquisition of rental property, the Company estimates the fair value of acquired tangible assets, consisting of land, building and improvements, and identified intangible assets and liabilities assumed, generally consisting of the fair value of (i) above and below market leases, (ii) in-place leases and (iii) tenant relationships.  The Company allocates the purchase price to the assets acquired and liabilities assumed based on their fair values.  The Company records goodwill or a gain on bargain purchase (if any) if the net assets acquired/liabilities assumed exceed the purchase consideration of a transaction.  In estimating the fair value of the tangible and intangible assets acquired, the Company considers information obtained about each property as a result of its due diligence and marketing and leasing activities, and utilizes various valuation methods, such as estimated cash flow projections utilizing appropriate discount and capitalization rates, estimates of replacement costs net of depreciation, and available market information.  The fair value of the tangible assets of an acquired property considers the value of the property as if it were vacant.
	Above-market and below-market lease values for acquired properties are initially recorded based on the present value (using a discount rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to each in-place lease and (ii) management’s estimate of fair market lease rates for each corresponding in-place lease, measured over a period equal to the remaining term of the lease for above-market leases and the remaining initial term plus the term of any below-market fixed rate renewal options for below-market leases. The capitalized above-market lease values are amortized as a reduction of base rental revenue over the remaining terms of the respective leases, and the capitalized below-market lease values are amortized as an increase to base rental revenue over the remaining initial terms plus the terms of any below-market fixed rate renewal options of the respective leases.
	Other intangible assets acquired include amounts for in-place lease values and tenant relationship values, which are based on management’s evaluation of the specific characteristics of each tenant’s lease and the Company’s overall relationship with the respective tenant.  Factors to be considered by management in its analysis of in-place lease values include an estimate of carrying costs during hypothetical expected lease-up periods considering current market conditions, and costs to execute similar leases.  In estimating carrying costs, management includes real estate taxes, insurance and other operating expenses and estimates of lost rentals at market rates during the expected lease-up periods, depending on local market conditions.  In estimating costs to execute similar leases, management considers leasing commissions, legal and other related expenses.  Characteristics considered by management in valuing tenant relationships include the nature and extent of the Company’s existing business relationships with the tenant, growth prospects for developing new business with the tenant, the tenant’s credit quality and expectations of lease renewals.  The value of in-place leases are amortized to expense over the remaining initial terms of the respective leases.  The value of tenant relationship intangibles are amortized to expense over the anticipated life of the relationships.
	On a periodic basis, management assesses whether there are any indicators that the value of the Company’s rental properties held for use may be impaired.  In addition to identifying any specific circumstances which may affect a property or properties, management considers other criteria for determining which properties may require assessment for potential impairment.  The criteria considered by management include reviewing low leased percentages, significant near-term lease expirations, recently acquired properties, current and historical operating and/or cash flow losses, near-term mortgage debt maturities or other factors that might impact the Company’s intent and ability to hold the property.  A property’s value is impaired only if management’s estimate of the aggregate future cash flows (undiscounted and without interest charges) to be generated by the property is less than the carrying value of the property.  To the extent impairment has occurred, the loss shall be measured as the excess of the carrying amount of the property over the fair value of the property.  The Company’s estimates of aggregate future cash flows expected to be generated by each property are based on a number of assumptions.  These assumptions are generally based on management’s experience in its local real estate markets and the effects of current market conditions.  The assumptions are subject to economic and market uncertainties including, among others, demand for space, competition for tenants, changes in market rental rates, and costs to operate each property.  As these factors are difficult to predict and are subject to future events that may alter management’s assumptions, the future cash flows estimated by management in its impairment analyses may not be achieved, and actual losses or impairments may be realized in the future.
Rental Property Held For Sale	Rental Property
	Held for SaleWhen assets are identified by management as held for sale, the Company discontinues depreciating the assets and estimates the sales price, net of selling costs, of such assets.  If, in management’s opinion, the estimated net sales price of the assets which have been identified as held for sale is less than the net book value of the assets, a valuation allowance is established.
	If circumstances arise that previously were considered unlikely and, as a result, the Company decides not to sell a property previously classified as held for sale, the property is reclassified as held and used.  A property that is reclassified is measured and recorded individually at the lower of (a) its carrying amount before the property was classified as held for sale, adjusted for any depreciation (amortization) expense that would have been recognized had the property been continuously classified as held and used, or (b) the fair value at the date of the subsequent decision not to sell.
Investments In Unconsolidated Joint Ventures	Investments in
	Unconsolidated
	Joint VenturesThe Company accounts for its investments in unconsolidated joint ventures under the equity method of accounting.  The Company applies the equity method by initially recording these investments at cost, as Investments in Unconsolidated Joint Ventures, subsequently adjusted for equity in earnings and cash contributions and distributions.  The outside basis portion of the Company’s joint ventures is amortized over the anticipated useful lives of the underlying ventures’ tangible and intangible assets acquired and liabilities assumed.  Generally, the Company would discontinue applying the equity method when the investment (and any advances) is reduced to zero and would not provide for additional losses unless the Company has guaranteed obligations of the venture or is otherwise committed to providing further financial support for the investee.    If the venture subsequently generates income, the Company only recognizes its share of such income to the extent it exceeds its share of previously unrecognized losses.
	On a periodic basis, management assesses whether there are any indicators that the value of the Company’s investments in unconsolidated joint ventures may be impaired.  An investment is impaired only if management’s estimate of the value of the investment is less than the carrying value of the investment, and such decline in value is deemed to be other than temporary.  To the extent impairment has occurred, the loss shall be measured as the excess of the carrying amount of the investment over the value of the investment.  The Company’s estimates of value for each investment (particularly in real estate joint ventures) are based on a number of assumptions that are subject to economic and market uncertainties including, among others, demand for space, competition for tenants, changes in market rental rates, and operating costs.  As these factors are difficult to predict and are subject to future events that may alter management’s assumptions, the values estimated by management in its impairment analyses may not be realized, and actual losses or impairment may be realized in the future.  See Note 4: Investments in Unconsolidated Joint Ventures.
Cash And Cash Equivalents	Cash and Cash
	EquivalentsAll highly liquid investments with a maturity of three months or less when purchased are considered to be cash equivalents.
Deferred Financing Costs
	Deferred
	Financing CostsCosts incurred in obtaining financing are capitalized and amortized over the term of the related indebtedness. Amortization of such costs is included in interest expense and was $953,000 and $769,000 for the three months ended March 31, 2015 and 2014, respectively.  If a financing obligation is extinguished early, any unamortized deferred financing costs are written off and included in gains (loss) from early extinguishment of debt.    No such unamortized costs were written off for the three months ended March 31, 2015 and 2014.
Deferred Leasing Costs	Deferred
	Leasing CostsCosts incurred in connection with commercial leases are capitalized and amortized on a straight-line basis over the terms of the related leases and included in depreciation and amortization.  Unamortized deferred leasing costs are charged to amortization expense upon early termination of the lease.  Certain employees of the Company are compensated for providing leasing services to the Properties.  The portion of such compensation related to commercial leases, which is capitalized and amortized, approximated $970,000 and $1,031,000 for the three months ended March 31, 2015 and 2014, respectively.
Goodwill	GoodwillGoodwill represents the excess of the purchase price over the fair value of net tangible and intangible assets acquired in a business combination. Goodwill is allocated to various reporting units, as applicable.  Each of the Company’s segments consists of a reporting unit. Goodwill is not amortized.  Management performs an annual impairment test for goodwill during the fourth quarter and between annual tests, management evaluates the recoverability of goodwill whenever events or changes in circumstances indicate that the carrying amount of goodwill may not be fully recoverable.  In its impairment tests of goodwill, management first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount.  If based on this assessment, management determines that the fair value of the reporting unit is not less than its carrying amount, then performing the additional two-step impairment test is unnecessary. If the carrying amount of goodwill exceeds its fair value, an impairment charge is recognized.
Derivative Instruments	Derivative
	InstrumentsThe Company measures derivative instruments, including certain derivative instruments embedded in other contracts, at fair value and records them as an asset or liability, depending on the Company’s rights or obligations under the applicable derivative contract.  For derivatives designated and qualifying as fair value hedges, the changes in the fair value of both the derivative instrument and the hedged item are recorded in earnings.  For derivatives designated as cash flow hedges, the effective portions of the derivative are reported in other comprehensive income (“OCI”) and are subsequently reclassified into earnings when the hedged item affects earnings. Changes in fair value of derivative instruments not designated as hedging and ineffective portions of hedges are recognized in earnings in the affected period.
Revenue Recognition	Revenue
	RecognitionBase rental revenue is recognized on a straight-line basis over the terms of the respective leases.  Unbilled rents receivable represents the cumulative amount by which straight-line rental revenue exceeds rents currently billed in accordance with the lease agreements.
	Above-market and below-market lease values for acquired properties are initially recorded based on the present value (using a discount rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to each in-place lease and (ii) management’s estimate of fair market lease rates for each corresponding in-place lease, measured over a period equal to the remaining term of the lease for above-market leases and the remaining initial term plus the term of any below-market fixed-rate renewal options for below-market leases.  The capitalized above-market lease values for acquired properties are amortized as a reduction of base rental revenue over the remaining terms of the respective leases, and the capitalized below-market lease values are amortized as an increase to base rental revenue over the remaining initial terms plus the terms of any below-market fixed-rate renewal options of the respective leases.
	Escalations and recoveries from tenants are received from tenants for certain costs as provided in the lease agreements.  These costs generally include real estate taxes, utilities, insurance, common area maintenance and other recoverable costs.  See Note 13: Tenant Leases.
	Real estate services revenue includes property management, development, construction and leasing commission fees and other services, and payroll and related costs reimbursed from clients.  Fee income derived from the Company’s unconsolidated joint ventures (which are capitalized by such ventures) are recognized to the extent attributable to the unaffiliated ownership interests.
	Parking income includes income from parking spaces leased to tenants and others.
	Other income includes income from tenants for additional services arranged for by the Company and income from tenants for early lease terminations.
Allowance For Doubtful Accounts	Allowance for
	Doubtful AccountsManagement performs a detailed review of amounts due from tenants to determine if an allowance for doubtful accounts is required based on factors affecting the collectability of the accounts receivable balances. The factors considered by management in determining which individual tenant receivable balances, or aggregate receivable balances, require a collectability allowance include the age of the receivable, the tenant’s payment history, the nature of the charges, any communications regarding the charges and other related information. Management’s estimate of the allowance for doubtful accounts requires management to exercise significant judgment about the timing, frequency and severity of collection losses, which affects the allowance and net income.
Income And Other Taxes	Income and
	Other TaxesThe Company has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “Code”).  As a REIT, the Company generally will not be subject to corporate federal income tax (including alternative minimum tax) on net income that it currently distributes to its shareholders, provided that the Company satisfies certain organizational and operational requirements including the requirement to distribute at least 90 percent of its REIT taxable income (determined by excluding any net capital gains) to its shareholders.  If and to the extent the Company retains and does not distribute any net capital gains, the Company will be required to pay federal, state and local taxes on such net capital gains at the rate applicable to capital gains of a corporation.  The Company has elected to treat certain of its corporate subsidiaries as taxable REIT subsidiaries (each a “TRS”).  In general, a TRS of the Company may perform additional services for tenants of the Company and generally may engage in any real estate or non-real estate related business (except for the operation or management of health care facilities or lodging facilities or the providing to any person, under a franchise, license or otherwise, rights to any brand name under which any lodging facility or health care facility is operated).  A TRS is subject to corporate federal income tax.   The Company has conducted business through its TRS entities for certain property management, development, construction and other related services, as well as to hold a joint venture interest in a hotel and other matters.
	As of March 31, 2015, the Company had a deferred tax asset related to its TRS activity with a balance of approximately $15.2 million which has been fully reserved for through a valuation allowance.  If the Company fails to qualify as a REIT in any taxable year, the Company will be subject to federal income tax (including any applicable alternative minimum tax) on its taxable income at regular corporate tax rates.  The Company is subject to certain state and local taxes.
	Pursuant to the amended provisions related to uncertain tax provisions of ASC 740, Income Taxes, the Company recognized no material adjustments regarding its tax accounting treatment.  The Company expects to recognize interest and penalties related to uncertain tax positions, if any, as income tax expense, which is included in general and administrative expense.
	In the normal course of business, the Company or one of its subsidiaries is subject to examination by federal, state and local jurisdictions in which it operates, where applicable.  As of March 31, 2015, the tax years that remain subject to examination by the major tax jurisdictions under the statute of limitations are generally from the year 2010 forward.
Earnings Per Share	Earnings
	Per ShareThe Company presents both basic and diluted earnings per share (“EPS”).  Basic EPS excludes dilution and is computed by dividing net income available to common shareholders by the weighted average number of shares outstanding for the period.  Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock, where such exercise or conversion would result in a lower EPS from continuing operations amount.  Shares whose issuance is contingent upon the satisfaction of certain conditions shall be considered outstanding and included in the computation of diluted EPS as follows (i) if all necessary conditions have been satisfied by the end of the period (the events have occurred), those shares shall be included as of the beginning of the period in which the conditions were satisfied (or as of the date of the grant, if later) or (ii) if all necessary conditions have not been satisfied by the end of the period, the number of contingently issuable shares included in diluted EPS shall be based on the number of shares, if any, that would be issuable if the end of the reporting period were the end of the contingency period (for example, the number of shares that would be issuable based on current period earnings or period-end market price) and if the result would be dilutive. Those contingently issuable shares shall be included in the denominator of diluted EPS as of the beginning of the period (or as of the date of the grant, if later).
Dividends And Distributions Payable	Dividends and
	Distributions
	PayableThe dividends and distributions payable at March 31, 2015 represents dividends payable to common shareholders (88,918,291 shares) and distributions payable to noncontrolling interest common unitholders of the Operating Partnership (11,036,898 common units) for all such holders of record as of April 6, 2015 with respect to the first quarter 2015.  The first quarter 2015 common stock dividends and common unit distributions of $0.15 per common share and unit were approved by the Board of Directors on March 10, 2015 and paid on April 14, 2015.
	The dividends and distributions payable at December 31, 2014 represents dividends payable to common shareholders (88,866,652 shares) and distributions payable to noncontrolling interest common unitholders of the Operating Partnership (11,083,876 common units) for all such holders of record as of January 6, 2015 with respect to the fourth quarter 2014.  The fourth quarter 2014 common stock dividends and common unit distributions of $0.15 per common share and unit were approved by the Board of Directors on December 9, 2014 and paid on January 14, 2015.
Costs Incurred For Stock Issuances	Costs Incurred
	For Stock
	IssuancesCosts incurred in connection with the Company’s stock issuances are reflected as a reduction of additional paid‑in capital.
Stock Compensation	Stock
	CompensationThe Company accounts for stock compensation in accordance with the provisions of ASC 718, Compensation-Stock Compensation.  These provisions require that the estimated fair value of restricted stock (“Restricted Stock Awards”), total stockholder return (“TSR”) based performance shares and stock options at the grant date be amortized ratably into expense over the appropriate vesting period.  The Company recorded stock compensation expense of $313,000 and $3,387,000 for the three months ended March 31, 2015 and 2014, respectively.  The amount for the three months ended March 31, 2014 included $3,203,000 related to the departure of executive officers.  See Note 12: Commitments and Contingencies ‑ Departure of Executive Officers.
Other Comprehensive Income	Other
	Comprehensive
	IncomeOther comprehensive income (loss), if any, includes items that are recorded in equity, such as unrealized holding gains or losses on marketable securities available for sale.  There was no difference in other comprehensive income to net income for the three months ended March 31, 2015 and 2014, and no accumulated other comprehensive income as of March 31, 2015 and December 31, 2014.
Fair Value Hierarchy	Fair Value
	HierarchyThe standard Fair Value Measurements specifies a hierarchy of valuation techniques based upon whether the inputs to those valuation techniques reflect assumptions other market participants would use based upon market data obtained from independent sources (observable inputs).  The following summarizes the fair value hierarchy:
		·	Level 1: Quoted prices in active markets that are unadjusted and accessible at the measurement date for identical, unrestricted assets or liabilities;
		·	Level 2: Quoted prices for identical assets and liabilities in markets that are inactive, quoted prices for similar assets and liabilities in active markets or financial instruments for which significant inputs are observable, either directly or indirectly, such as interest rates and yield curves that are observable at commonly quoted intervals and
		·	Level 3: Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable.
	In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy.  In such cases, the level in the fair value hierarchy within which the fair value measurement in its entirety falls has been determined based on the lowest level input that is significant to the fair value measurement in its entirety.  The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability.
Discontinued Operations	Discontinued
	OperationsIn April 2014, the FASB issued guidance related to the reporting of discontinued operation and disclosures of disposals of components of an entity.  This guidance defines a discontinued operation as a component or group of components disposed or classified as held for sale and represents a strategic shift that has (or will have) a major effect on an entity’s operations and final result; the guidance states that a strategic shift could include a disposal of a major geographical area of operations, a major line of business, a major equity method investment or other major parts of an entity.  The guidance also provides for additional disclosure requirements in connection with both discontinued operations and other dispositions not qualifying as discontinued operations.  The guidance is effective for all companies for annual and interim periods beginning on or after December 15, 2014.  The guidance applies prospectively to new disposals and new classifications of disposal groups as held for sale after the effective date.  All entities could early adopt the guidance for new disposals (or new classifications as held for sale) that had not been reported in financial statements previously issued or available for issuance.    The Company elected to early adopt this standard effective with the interim period beginning January 1, 2014.    Prior to January 1, 2014, properties identified as held for sale and/or disposed of were presented in discontinued operations for all periods presented.
Impact Of Recently-Issued Accounting Standards	Impact Of
	Recently-Issued
	Accounting
	StandardsIn May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09 Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"). ASU 2014-09 is a comprehensive new revenue recognition model requiring a company to recognize revenue to depict the transfer of goods or services to a customer at an amount reflecting the consideration it expects to receive in exchange for those goods or services. In adopting ASU 2014-09, companies may use either a full retrospective or a modified retrospective approach. Additionally, this guidance requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers.  ASU 2014-09 is effective for the first interim period within annual reporting periods beginning after December 15, 2017, and early adoption is permitted for periods beginning after December 15, 2016.  The Company is currently in the process of evaluating the impact the adoption of ASU 2014-09 will have on the Company’s financial position or results of operations.
	In August 2014, the FASB issued ASU 2014-15, which requires management to evaluate whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern, and to provide certain disclosures when it is probable that the entity will be unable to meet its obligations as they become due within one year after the date that the financial statements are issued. ASU 2014-15 is effective for the annual period ended December 31, 2016 and for annual periods and interim periods thereafter with early adoption permitted. The adoption of ASU 2014-15 is not expected to materially impact the Company’s consolidated financial statements.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2015
Significant Accounting Policies [Abstract]
Estimated Useful Lives Of Assets	Leasehold interests	Remaining lease term
	Buildings and improvements	5 to 40 years
	Tenant improvements	The shorter of the term of the
		related lease or useful life
	Furniture, fixtures and equipment	5 to 10 years

Real_Estate_Transactions_Table

Real Estate Transactions (Tables)	3 Months Ended
	Mar. 31, 2015
Real Estate Transactions [Abstract]
Summary Of Income From Properties Sold
			Three Months Ended
			March 31,
			2015		2014
	Total revenues	$	8	$	14,969
	Operating and other expenses		-3		-9,253
	Depreciation and amortization		-2		-3,394
	Income from properties sold	$	3	$	2,322
	Realized gains (losses) on sales, net		144		-
	Total income (loss) from properties sold	$	147	$	2,322

Investments_In_Unconsolidated_1

Investments In Unconsolidated Joint Ventures (Tables)	3 Months Ended
	Mar. 31, 2015
Investments In Unconsolidated Joint Ventures [Abstract]
Summary Of Unconsolidated Joint Ventures
												Property Debt
		Number of		Company's				Carrying Amount				As of March 31, 2015
		Apartment Units		Effective				March 31,		December 31,			Maturity	Interest
	Entity / Property Name	or Square Feet (sf)		Ownership % (a)				2015		2014		Balance	Date	Rate
	Multi-family
	Marbella RoseGarden, L.L.C./ Marbella  (b)	412	units	24.27	%		$	15,839	$	15,779	$	95,000	5/1/18	4.99	%
	RoseGarden Monaco Holdings, L.L.C./ Monaco   (b)	523	units	15.00	%			1,845		2,161		165,000	2/1/21	4.19	%
	Rosewood Lafayette Holdings, L.L.C./ Highlands at Morristown Station  (b)	217	units	25.00	%			-		62		38,478	7/1/15	4.00	%
	PruRose Port Imperial South 15, LLC /RiversEdge at Port Imperial (b)	236	units	50.00	%			-		-		57,500	9/1/20	4.32	%
	Rosewood Morristown, L.L.C. / Metropolitan at 40 Park  (c) (d)	130	units	12.50	%			5,920		6,029		46,217	(e)	(e)
	Overlook Ridge JV, L.L.C./ Quarrystone at Overlook Ridge  (b)	251	units	50.00	%			-		-		69,420	(f)	(f)
	Overlook Ridge JV 2C/3B, L.L.C./The Chase at Overlook Ridge  (b)	371	units	50.00	%			2,304		2,524		51,447	12/26/15	L+2.50	%	(g)
	PruRose Riverwalk G, L.L.C./ RiverTrace at Port Imperial   (b)	316	units	25.00	%			701		955		79,154	7/15/21	6.00	%	(h)
	Elmajo Urban Renewal Associates, LLC / Lincoln Harbor (Bldg A&C) (b)	355	units	7.50	%			-		-		128,100	3/1/30	4.00	%	(i)
	Crystal House Apartments Investors LLC / Crystal House  (j)	828	units	25.00	%			27,340		27,051		165,000	4/1/20	3.17	%
	Portside Master Company, L.L.C./ Portside at Pier One - Bldg 7  (b)	176	units	38.25	%			1,017		1,747		38,990	12/4/15	L+2.50	%	(k)
	PruRose Port Imperial South 13, LLC / RiverParc at Port Imperial  (b)	280	units	20.00	%			815		1,087		56,999	6/27/16	L+2.15	%	(l)
	Roseland/Port Imperial Partners, L.P./ Riverwalk C  (b) (m)	363	units	20.00	%			1,755		1,800		-	-	-
	RoseGarden Marbella South, L.L.C./ Marbella II	311	units	24.27	%			12,920		11,282		43,090	3/30/17	L+2.25	%	(n)
	Estuary Urban Renewal Unit B, LLC / Lincoln Harbor (Bldg B)  (b)	227	units	7.50	%			-		-		81,900	3/1/30	4.00	%	(o)
	Riverpark at Harrison I, L.L.C./ Riverpark at Harrison	141	units	36.00	%			4,571		4,744		23,095	6/27/16	L+2.35	%	(p)
	Capitol Place Mezz LLC / Station Townhouses	377	units	50.00	%			49,873		49,327		73,971	7/1/33	4.82	%	(q)
	Harborside Unit A Urban Renewal, L.L.C. / URL Harborside	763	units	85.00	%			52,263		34,954		-	8/1/29	5.197	%	(r)
	RoseGarden Monaco, L.L.C./ San Remo Land	300	potential units	41.67	%			1,283		1,283		-	-	-
	Grand Jersey Waterfront URA, L.L.C./ Liberty Landing	1,000	potential units	50.00	%			337		337		-	-	-
	Office
	Red Bank Corporate Plaza, L.L.C./ Red Bank	92,878	sf	50.00	%			4,081		3,963		15,682	5/17/16	L+3.00	%	(s)
	12 Vreeland Associates, L.L.C./ 12 Vreeland Road	139,750	sf	50.00	%			5,606		5,620		13,679	7/1/23	2.87	%
	BNES Associates III / Offices at Crystal Lake	106,345	sf	31.25	%			2,061		1,993		6,603	11/1/23	4.76	%
	Hillsborough 206 Holdings, L.L.C./ Hillsborough 206	160,000	sf	50.00	%			1,962		1,962		-	-	-
	KPG-P 100 IMW JV, LLC / 100 Independence Mall West	339,615	sf	33.33	%			416		-		61,500	9/9/16	L+7.00	%	(t)
	Keystone-Penn	1,842,820	sf	(u)				-		-		205,946	(v)	(v)
	Keystone-TriState	1,266,384	sf	(w)				4,792		6,140		205,112	(x)	(x)
	KPG-MCG Curtis JV, L.L.C./ Curtis Center  (y)	885,000	sf	50.00	%			58,341		59,911		(z)	(z)	(z)
	Other
	Plaza VIII & IX Associates, L.L.C./ Vacant land (parking operations)	1,225,000	sf	50.00	%			3,796		4,022		-	-	-
	Roseland/North Retail, L.L.C./ Riverwalk at Port Imperial  (b)	30,745	sf	20.00	%			1,810		1,828		-	-	-
	South Pier at Harborside / Hyatt Regency Jersey City on the Hudson	350	rooms	50.00	%			(aa)		(aa)		65,308	(ab)	(ab)
	Stamford SM LLC / Senior Mezzanine Loan  (ac)	n/a	n/a	80.00	%			-		-		-	-	-
	Other (ad)							404		907		-	-	-
	Totals:						$	262,052	$	247,468	$	1,787,191
	(a)	Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.
	(b)	The Company's ownership interests in this venture are subordinate to its partner's preferred capital balance and the Company is not expected to meaningfully participate in the venture's cash flows in the near term.
	(c)	Through the joint venture, the Company also owns a 12.5 percent interest in a 50,973 square feet retail building ("Shops at 40 Park") and a 25 percent interest in a to-be-built 59-unit, five story multi-family rental development property ("Lofts at 40 Park").
	(d)	The Company's ownership interests in this venture are subordinate to its partner's preferred capital balance and the payment of the outstanding balance remaining on a note ($975 as of March 31, 2015), and is not expected to meaningfully participate in the venture's cash flows in the near term.
	(e)	Property debt balance consists of: (i) a loan, collateralized by the Metropolitan at 40 Park, with a balance of $38,600 at March 31, 2015, bears interest at 3.25 percent, matures in September 2020 and is interest only through September 2015; (ii) a loan, collateralized by the Shops at 40 Park, with a balance of $6,500 at March 31, 2015, bears interest at 3.63 percent, matures in August 2018 and is interest-only through July 2015; and (iii) a loan, collateralized by the Lofts at 40 Park, with a balance of $1,117, bears interest at LIBOR plus 250 basis points and matures in September 2015.  The Shops at 40 Park mortgage loan also provides for additional borrowing proceeds of $1 million based on certain preferred thresholds being achieved.
	(f)	Property debt balance consists of: (i) the senior loan, collateralized by the Quarrystone property, with a balance of $52,420 at March 31, 2015, bears interest at LIBOR plus 200 basis, matures in March 2016 and (ii) the junior loan, with a balance of $17,000, bears interest at LIBOR plus 90 basis points, matures in March 2016 and is collateralized by a $17,000 letter of credit provided by an affiliate of the partner.
	(g)	The construction loan has a maximum borrowing amount of $55,500 and provides, subject to certain conditions, two one-year extension options with a fee of 25 basis points each.  The joint venture has a swap agreement that fixes the all-in rate to 3.0875 percent per annum on an initial notional amount of $1,840, increasing to $52,000, for the period from September 3, 2013 to November 2, 2015.
	(h)	The permanent loan has a maximum borrowing amount of $80,249.
	(i)	The construction loan with a maximum borrowing amount of $91,000 converted to a permanent loan on February 27, 2015.
	(j)	The Company also owns a 50 percent interest in a vacant land to accommodate the development of approximately 295 additional units of which 252 are currently approved.
	(k)	The construction loan has a maximum borrowing amount of $42,500 and provides, subject to certain conditions, two two-year extension options with a fee of 12.5 basis points for the first two-year extension and 25 basis points for the second two-year extension.
	(l)	The construction loan has a maximum borrowing amount of $73,350 and provides, subject to certain conditions, one-year extension option followed by a six-month extension option with a fee of 25 basis points each. The joint venture has a swap agreement that fixes the all-in rate to 2.79 percent per annum on an initial notional amount of $1,620, increasing to $69,500 for the period from July 1, 2013 to January 1, 2016.
	(m)	The Company also owns a 20 percent residual interest in undeveloped land parcels: parcels 6, I, and J ("Port Imperial North Land") that can accommodate the development of 836 apartment units.
	(n)	The construction loan has a maximum borrowing amount of $77,400 and provides, subject to certain conditions, two one-year extension options with a fee of 25 basis points for each year.
	(o)	The construction loan with a maximum borrowing amount of $57,000 converted to a permanent loan on February 27, 2015.
	(p)	The construction loan has a maximum borrowing amount of $23,400 and provides, subject to certain conditions, two one-year extension options with a fee of 20 basis points for each year.
	(q)	The construction/permanent loan has a maximum borrowing amount of $100,700 with amortization starting in August 2017.
	(r)	The construction/permanent loan has a maximum borrowing amount of $192,000.
	(s)	The joint venture has a swap agreement that fixes the all-in rate to 3.99375 percent per annum on an initial notional amount of $13,650 and then adjusting in accordance with an amortization schedule, which is effective from October 17, 2011 through loan maturity.
	(t)	The mortgage loan has two one-year extension options, subject to certain conditions, and includes a $25 million construction escrow with a balance of $13.6 million to be drawn at March 31, 2015.
	(u)	The Company’s equity interests in the joint ventures will be subordinated to Keystone Entities receiving a 15 percent internal rate of return (“IRR”) after which the Company will receive a 10 percent IRR on its subordinate equity and then all profit will be split equally.
	(v)	Principal balance of $127,600 bears interest at 5.114 percent and matures in August 27, 2023; principal balance of $67,921 bears interest at rates ranging from LIBOR+5.0 percent to LIBOR+5.75 percent and matures in August 27, 2016; principal balance of $10,425 bears interest at LIBOR+6.0 percent matures in August 27, 2015.
(w)	Includes the Company’s pari-passu interests of $4.8 million in five properties and Company’s subordinated equity interests to Keystone Entities receiving a 15 percent internal rate of return (“IRR”) after which the Company will receive a 10 percent IRR on its subordinate equity and then all profit will be split equally.
(x)	Principal balance of $41,240 bears interest at 4.95 percent and matures on July 1, 2017; principal balance of $71,172 bears interest at rates ranging from 5.65 percent to 6.75 percent and matures on September 9, 2017; principal balance of $14,250 bears interest at 4.88 percent and matures on July 6, 2024; principal balance of $63,400 bears interest at 4.93 percent and matures on July 6, 2044; principal balance of $15,050 bears interest at 4.71 percent and matures on August 6, 2044.
(y)	Includes undivided interests in the same manner as investments in noncontrolling partnership, pursuant to ASC 970-323-25-12.
(z)	See Note 9: Mortgages, Loans Payable and Other Obligations for debt secured by interests in these assets.
(aa)	The negative carrying amount for this venture of $1,937 and $1,854 as of March 31, 2015 and December 31, 2014, respectively, were included in accounts payable, accrued expenses and other liabilities.
(ab)	Balance includes: (i) mortgage loan, collateralized by the hotel property, with a balance of $61,184, bears interest at 6.15 percent and matures in November 2016, and (ii) loan with a balance of $4.1 million, bears interest at fixed rates ranging from 6.09 percent to 6.62 percent and matures in August 1, 2020.  The Company posted a $4.1 million letter of credit in support of this loan, half of which is indemnified by the partner.
(ac)	The joint venture collected net proceeds of $47.2 million at maturity, of which the Company received its share of $37.8 million on August 6, 2014.
(ad)	The Company owns other interests in various unconsolidated joint ventures, including interests in assets previously owned and interest in ventures whose businesses are related to its core operations. These ventures are not expected to significantly impact the Company's operations in the near term.
Summary Of Company's Equity In Earnings (Loss) Of Unconsolidated Joint Ventures
			Three Months Ended
			March 31,
	Entity / Property Name		2015			2014
	Multi-family
	Marbella RoseGarden, L.L.C./ Marbella	$	61		$	-6
	RoseGarden Monaco Holdings, L.L.C./ Monaco		-317			-277
	Rosewood Lafayette Holdings, L.L.C./ Highlands at Morristown Station		-62			-216
	PruRose Port Imperial South 15, LLC /RiversEdge at Port Imperial		-			-
	Rosewood Morristown, L.L.C. / Metropolitan at 40 Park		-94			-98
	Overlook Ridge JV, L.L.C./ Quarrystone at Overlook Ridge		-			-
	Overlook Ridge JV 2C/3B, L.L.C./The Chase at Overlook Ridge		-220			62
	PruRose Riverwalk G, L.L.C./ RiverTrace at Port Imperial		-254			-538
	Elmajo Urban Renewal Associates, LLC / Lincoln Harbor (Bldg A&C)		-			-112
	Crystal House Apartments Investors LLC / Crystal House		-10			-327
	Portside Master Company, L.L.C./ Portside at Pier One - Bldg 7		-719			-213
	PruRose Port Imperial South 13, LLC / RiverParc at Port Imperial		-225			-206
	Roseland/Port Imperial Partners, L.P./ Riverwalk C		-184			-164
	RoseGarden Marbella South, L.L.C./ Marbella II		-			-
	Estuary Urban Renewal Unit B, LLC / Lincoln Harbor (Bldg B)		-			-15
	Riverpark at Harrison I, L.L.C./ Riverpark at Harrison		-173			-
	Capitol Place Mezz LLC / Station Townhouses		75			-
	Harborside Unit A Urban Renewal, L.L.C. / URL Harborside		-			-
	RoseGarden Monaco, L.L.C./ San Remo Land		-			-
	Grand Jersey Waterfront URA, L.L.C./ Liberty Landing		-19			-37
	Office
	Red Bank Corporate Plaza, L.L.C./ Red Bank		110			99
	12 Vreeland Associates, L.L.C./ 12 Vreeland Road		-14			89
	BNES Associates III / Offices at Crystal Lake		68			36
	Hillsborough 206 Holdings, L.L.C./ Hillsborough 206		-			-5
	KPG-P 100 IMW JV, LLC / 100 Independence Mall West		-384			-653
	Keystone-Penn		-			-
	Keystone-TriState		-1,348			-
	KPG-MCG Curtis JV, L.L.C./ Curtis Center		196			-
	Other
	Plaza VIII & IX Associates, L.L.C./ Vacant land (parking operations)		86			102
	Roseland/North Retail, L.L.C./ Riverwalk at Port Imperial		-18			-24
	South Pier at Harborside / Hyatt Regency Jersey City on the Hudson		-84			398
	Stamford SM LLC / Senior Mezzanine Loan		-			916
	Other		-			-46
	Company's equity in earnings (loss) of unconsolidated joint ventures	$	-3,529		$	-1,235
Summary Of Financial Position Of Unconsolidated Joint Ventures
				March 31,			December 31,
				2015			2014
	Assets:
	Rental property, net		$	1,546,589		$	1,534,812
	Other assets			410,410			398,222
	Total assets		$	1,956,999		$	1,933,034
	Liabilities and partners'/
	members' capital:
	Mortgages and loans payable		$	1,162,732		$	1,060,020
	Other liabilities			214,572			211,340
	Partners'/members' capital			579,695			661,674
	Total liabilities and
	partners'/members' capital		$	1,956,999		$	1,933,034
Summary Of Results Of Operations Of Unconsolidated Joint Ventures
			Three Months Ended
			March 31,
			2015			2014
	Total revenues	$	74,477		$	30,993
	Operating and other expenses		-57,356			-18,353
	Depreciation and amortization		-16,993			-8,368
	Interest expense		-11,334			-6,341
	Net loss	$	-11,206		$	-2,069

Deferred_Charges_Goodwill_And_1

Deferred Charges, Goodwill And Other Assets (Tables)	3 Months Ended
	Mar. 31, 2015
Deferred Charges, Goodwill And Other Assets [Abstract]
Schedule Of Deferred Charges, Goodwill And Other Assets
			March 31,			December 31,
	(dollars in thousands)		2015			2014
	Deferred leasing costs	$	226,649		$	239,138
	Deferred financing costs		20,755			24,042
			247,404			263,180
	Accumulated amortization		-107,601			-122,358
	Deferred charges, net		139,803			140,822
	Notes receivable (a)		21,430			21,491
	In-place lease values, related intangibles and other assets, net		6,021			6,565
	Goodwill		2,945			2,945
	Prepaid expenses and other assets, net		40,561			32,827
	Total deferred charges, goodwill and other assets, net	$	210,760		$	204,650
	(a)Includes as of March 31, 2015: a mortgage receivable for $10.4 million which bears interest at LIBOR plus six percent and matures in August 2015; a note receivable for $7.8 million which bears interest at eight percent and matures in October 2017 (which was repaid in full to the Company on April 15, 2015); and an interest-free note receivable with a net present value of $3.3 million and matures in April 2023.  The Company believes these balances are fully collectible.
Summary Of Notional And Fair Value Of Derivative Financial Instruments
										Fair Value
			Notional			Strike		Effective	Expiration		March 31,		December 31,
			Value	(a)		Rate		Date	Date		2015		2014
	LIBOR Cap	$	51,000			1.5	%	Sep-14	Oct-15	$	1	$	1
	LIBOR Cap		24,000			1.5	%	Sep-14	Oct-15		1		1
	LIBOR Cap		51,000			1.75	%	Oct-15	Oct-16		20		64
	LIBOR Cap		24,000			1.75	%	Oct-15	Oct-16		10		29
										$	32	$	95
		(a)		The notional value is an indication of the extent of our involvement in these instruments at that time, but does not represent exposure to credit, interest rate or market risks.

Restricted_Cash_Tables

Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2015
Restricted Cash [Abstract]
Schedule Of Restricted Cash
			March 31,		December 31,
			2015		2014
	Security deposits	$	7,868	$	7,795
	Escrow and other reserve funds		27,912		26,450
	Total restricted cash	$	35,780	$	34,245

Senior_Unsecured_Notes_Tables

Senior Unsecured Notes (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Summary Of Senior Unsecured Notes
			March 31,		December 31,	Effective
			2015		2014	Rate (1)
	5.800% Senior Unsecured Notes, due January 15, 2016	$	200,066	$	200,086	5.806	%
	2.500% Senior Unsecured Notes, due  December 15, 2017		249,224		249,150	2.803	%
	7.750% Senior Unsecured Notes, due August 15, 2019		249,066		249,013	8.017	%
	4.500% Senior Unsecured Notes, due April 18, 2022		299,580		299,565	4.612	%
	3.150% Senior Unsecured Notes, due May 15, 2023		270,082		269,930	3.517	%
	Total senior unsecured notes	$	1,268,018	$	1,267,744
	(1)Includes the cost of terminated treasury lock agreements (if any), offering and other transaction costs and the discount/premium on the notes, as applicable.

Unsecured_Revolving_Credit_Fac1

Unsecured Revolving Credit Facility (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Change In The Operating Partnership's Unsecured Debt Ratings
	Operating Partnership's	Interest Rate -
	Unsecured Debt Ratings:	Applicable Basis Points	Facility Fee
	Higher of S&P or Moody's	Above LIBOR	Basis Points
	No ratings or less than BBB-/Baa3	170.0	35.0
	BBB- or Baa3 (current)	130.0	30.0
	BBB or Baa2	110.0	20.0
	BBB+ or Baa1	100.0	15.0
	A- or A3 or higher	92.5	12.5

Mortgages_Loans_Payable_And_Ot1

Mortgages, Loans Payable And Other Obligations (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Summary Of Mortgages, Loans Payable And Other Obligations
				Effective				March 31,		December 31,
	Property Name	Lender		Rate (a)				2015		2014		Maturity
	Overlook - Site IIID,IIIC, IIIA (b)	Wells Fargo Bank N.A.	LIBOR+3.50		%			-	$	17,260
	Overlook - Site IIB (Quarrystone I) (b)	Wells Fargo Bank N.A.	LIBOR+2.50		%			-		5,787
	6 Becker, 85 Livingston,	Wells Fargo CMBS		10.260	%		$	65,035		65,035		8/11/14	(d)
	75 Livingston &
	20 Waterview (c)
	4 Sylvan	Wells Fargo CMBS		10.260	%			14,575		14,575		8/11/14	(d)
	10 Independence	Wells Fargo CMBS		10.260	%			16,924		16,924		8/11/14	(d)
	9200 Edmonston Road (e)	Principal Commercial Funding L.L.C.		5.534	%			3,903		3,951		5/1/15
	Port Imperial South	Wells Fargo Bank N.A.	LIBOR+1.75		%			44,333		44,119		9/19/15
	4 Becker	Wells Fargo CMBS		9.550	%			39,568		39,421		5/11/16
	5 Becker (f)	Wells Fargo CMBS		19.450	%			14,073		13,867		5/11/16
	210 Clay  (g)	Wells Fargo CMBS		18.100	%			13,549		13,330		5/11/16
	Curtis Center (h)	CCRE & PREFG	LIBOR+5.912		%	(k)		64,000		64,000		10/9/16
	Various (i)	Prudential Insurance		6.332	%			145,058		145,557		1/15/17
	150 Main St.	Webster Bank	LIBOR+2.35		%			1,963		1,193	(m)	3/30/17
	23 Main Street	JPMorgan CMBS		5.587	%			29,041		29,210		9/1/18
	Harborside Plaza 5	The Northwestern Mutual Life		6.842	%			220,630		221,563		11/1/18
		Insurance Co. & New York Life
		Insurance Co.
	100 Walnut Avenue	Guardian Life Insurance Co.		7.311	%			18,476		18,542		2/1/19
	One River Center (j)	Guardian Life Insurance Co.		7.311	%			42,326		42,476		2/1/19
	Park Square	Wells Fargo Bank N.A.	LIBOR+1.872		%	(l)		27,500		27,500		4/10/19
	Port Imperial South 4/5 Retail	American General Life & A/G PC		4.559	%			4,000		4,000		12/1/21
	Port Imperial South 4/5 Garage	American General Life & A/G PC		4.853	%			32,600		32,600		12/1/29
	Total mortgages, loans payable and other obligations						$	797,554	$	820,910
	(a)	Reflects effective rate of debt, including deferred financing costs, comprised of the cost of terminated treasury lock agreements (if any), debt initiation costs, mark-to-market adjustment of acquired debt and other transaction costs, as applicable.
	(b)	On March 27, 2015, the Company repaid these loans at par, using borrowings on the Company's unsecured revolving credit facility.
	(c)	Mortgage is cross collateralized by the four properties.
	(d)	The loan was not repaid at maturity and the Company has begun discussions with the lender regarding a potential deed-in-lieu of foreclosure in satisfaction of the obligation.
	(e)	The mortgage loan originally matured on May 1, 2013.  The maturity date was extended until May 1, 2015 with the same interest rate.  Excess cash flow, as defined, is being held by the lender for re-leasing costs.  The deed for the property was placed in escrow and is available to the lender in the event of default or non-payment at maturity.
	(f)	The cash flow from this property is insufficient to cover operating costs and debt service.  Consequently, the Company notified the lender and suspended debt service payments in August 2013.  The Company has begun discussions with the lender regarding a deed-in-lieu of foreclosure and began remitting available cash flow to the lender effective August 2013.
	(g)	The cash flow from this property is insufficient to cover operating costs and debt service.  Consequently, the Company notified the lender and suspended debt service payments in January 2015.
	(h)	The Company owns a 50 percent tenants-in-common interest in the Curtis Center property.  The Company’s $64.0 million loan consists of its 50 percent interest in a $102 million senior loan with a current rate of 3.469 percent at March 31, 2015 and its 50 percent interest in a $26 million mezzanine loan (with a maximum borrowing capacity of $48 million) with a current rate of 9.675 percent at March 31, 2015.  The senior loan rate is based on a floating rate of one-month LIBOR plus 329 basis points and the mezzanine loan rate is based on a floating rate of one-month LIBOR plus 950 basis points.  The Company has entered into LIBOR caps for the periods of the loans.  The loans provide for three one-year extension options.
	(i)	Mortgage is cross collateralized by seven properties. The Company has agreed, subject to certain conditions, to guarantee repayment of a portion of the loan.
	(j)	Mortgage is collateralized by the three properties comprising One River Center.
	(k)	The effective interest rate includes amortization of deferred financing costs of 1.362 percent.
	(l)	The effective interest rate includes amortization of deferred financing costs of 0.122 percent.
	(m)	This construction loan has a maximum borrowing capacity of $28.8 million.

Commitments_And_Contingencies_

Commitments And Contingencies (Tables)	3 Months Ended
	Mar. 31, 2015
Commitments And Contingencies [Abstract]
Future Minimum Rental Payments Of Ground Leases
	Year		Amount
	April 1 through December 31, 2015	$	278
	2016		371
	2017		267
	2018		232
	2019		235
	2020 through 2084		15,584
	Total	$	16,967

Tenant_Leases_Tables

Tenant Leases (Tables)	3 Months Ended
	Mar. 31, 2015
Tenant Leases [Abstract]
Future Minimum Rentals To Be Received Under Non-Cancelable Operating Leases
	Year		Amount
	April 1 through December 31, 2015	$	342,120
	2016		432,644
	2017		381,749
	2018		301,126
	2019		245,082
	2020 and thereafter		982,973
	Total	$	2,685,694

MackCali_Realty_Corporation_St1

Mack-Cali Realty Corporation Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2015
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]
Schedule Of Stock Option Plans
					Weighted		Aggregate
					Average		Intrinsic
		Shares			Exercise		Value
		Under Options			Price		$(000’s)
	Outstanding at January 1, 2015	10,000		$	33.36		-
	Granted, lapsed or cancelled	-			-
	Outstanding at March 31, 2015  ($21.25 – $45.47)	10,000		$	33.36		-
	Options exercisable at March 31, 2015	5,000
	Available for grant at March 31, 2015	4,420,227
Schedule Of Restricted Stock Awards
					Weighted-Average
					Grant – Date
		Shares			Fair Value
	Outstanding at January 1, 2015	346,946		$	21.09
	Granted	3,786			19.53
	Vested	-37,392			21.59
	Forfeited	-3			26.36
	Outstanding at March 31, 2015	313,337		$	21.01
Schedule Of Basic And Diluted Earnings Per Share
			Three Months Ended
			March 31,
	Computation of Basic EPS		2015			2014
	Net loss	$	-3,325		$	-17,628
	Add: Noncontrolling interest in consolidated joint ventures		490			322
	Add:  Noncontrolling interest in Operating Partnership		314			2,008
	Net loss available to common shareholders	$	-2,521		$	-15,298
	Weighted average common shares		89,192			88,289
	Basic EPS:
	Net loss available to common shareholders	$	-0.03		$	-0.17
			Three Months Ended
			March 31,
	Computation of Diluted EPS		2015			2014
	Net loss available to common shareholders	$	-2,521		$	-15,298
	Add (deduct): Noncontrolling interest in Operating Partnership		-314			-2,008
	Net loss for diluted earnings per share	$	-2,835		$	-17,306
	Weighted average common shares		100,266			99,876
	Diluted EPS:
	Net loss available to common shareholders	$	-0.03		$	-0.17
	The following schedule reconciles the shares used in the basic EPS calculation to the shares used in the diluted EPS calculation: (in thousands)
		Three Months Ended
		March 31,
		2015	2014
	Basic EPS shares	89,192	88,289
	Add:   Operating Partnership – common units	11,074	11,587
	Diluted EPS Shares	100,266	99,876

Noncontrolling_Interests_In_Su1

Noncontrolling Interests In Subsidiaries (Tables)	3 Months Ended
	Mar. 31, 2015
Noncontrolling Interests In Subsidiaries [Abstract]
Changes In Noncontrolling Interests Of Subsidiaries
		Common
		Units
	Balance at January 1, 2015	11,083,876
	Redemption of common units for shares of common stock	-46,978
	Balance at March 31, 2015	11,036,898
Schedule Of Activity Of Noncontrolling Interests
			Three Months Ended
			March 31,
			2015		2014
	Balance at January 1	$	257,230	$	276,096
	Net loss		-804		-2,330
	Common unit distributions		-1,656		-3,455
	Increase in noncontrolling interests in consolidated joint ventures		94		-
	Redemption of common units
	for common stock		-857		-6,452
	Rebalancing of ownership percentage
	between parent and subsidiaries		45		-21
	Balance at March 31	$	254,052	$	263,838

Segment_Reporting_Tables

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Schedule Of Segment Reporting Information, By Segment
			Real Estate
			Commercial				Multi-family			Corporate		Total
			& Other		Multi-family		Services			& Other (d)		Company
	Total revenues:
	Three months ended:
	31-Mar-15	$	139,759	$	6,584	$	8,232	(e)	$	-860	$	153,715
	31-Mar-14		157,520		5,801		6,948	(f)		-673		169,596
	Total operating and
	interest expenses (a):
	Three months ended:
	31-Mar-15	$	72,198	$	3,321	$	9,655		$	27,679	$	112,853
	31-Mar-14		86,933		2,701		10,159			41,211		141,004
	Equity in earnings (loss) of
	unconsolidated joint ventures:
	Three months ended:
	31-Mar-15	$	-1,368	$	-2,161	$	-		$	-	$	-3,529
	31-Mar-14		988		-2,223		-			-		-1,235
	Net operating income (loss) (b):
	Three months ended:
	31-Mar-15	$	66,193	$	1,102	$	-1,423		$	-28,539	$	37,333
	31-Mar-14		71,575		877		-3,211			-41,884		27,357
	Total assets:
	31-Mar-15	$	3,627,443	$	515,643	$	11,154		$	44,614	$	4,198,854
	31-Dec-14		3,636,126		492,362		11,158			52,601		4,192,247
	Total long-lived assets (c):
	31-Mar-15	$	3,336,340	$	321,295	$	3,811		$	3,004	$	3,664,450
	31-Dec-14		3,344,840		318,524		3,858			3,482		3,670,704
	Total investments in
	unconsolidated joint ventures:
	31-Mar-15	$	79,094	$	182,554	$	404		$	-	$	262,052
	31-Dec-14		81,649		164,912		907			-		247,468
	(a)Total operating and interest expenses represent the sum of: real estate taxes; utilities; operating services; direct construction costs; real estate services expenses; general and administrative and interest expense (net of interest income).  All interest expense, net of interest and other investment income, (including for property-level mortgages) is excluded from segment amounts and classified in Corporate & Other for all periods.
	(b)Net operating income represents total revenues less total operating and interest expenses (as defined in Note “a”), plus equity in earnings (loss) of unconsolidated joint ventures, for the period.
	(c)Long-lived assets are comprised of net investment in rental property, unbilled rents receivable and goodwill.
	(d)Corporate & Other represents all corporate-level items (including interest and other investment income, interest expense, non-property general and administrative expense, construction services revenue and direct construction costs) as well as intercompany eliminations necessary to reconcile to consolidated Company totals.
	(e)Includes $1.3 million of fees earned for this period from the multi-family real estate segment, which are eliminated in consolidation.
	(f)Includes $0.8 million of fees earned for this period from the multi-family real estate segment, which are eliminated in consolidation.
	The following schedule reconciles net operating income to net income available to common shareholders: (dollars in thousands)
			Three Months Ended
			March 31,
			2015		2014
	Net operating income	$	37,333	$	27,357
	Add (deduct):
	Depreciation and amortization		-40,802		-44,985
	Realized gains on disposition of
	rental property, net		144		-
	Net loss		-3,325		-17,628
	Noncontrolling interest in consolidated joint ventures		490		322
	Noncontrolling interest in Operating Partnership		314		2,008
	Net loss available to common shareholders	$	-2,521	$	-15,298

Organization_And_Basis_Of_Pres1

Organization And Basis Of Presentation (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
	sqft
	state
	property
Real Estate Properties [Line Items]
Number of properties owned or investment interests	283
Aggregate square feet of the property owned or investment interest	30,900,000
Number of states where properties are located	7
Consolidated joint ventures, total real estate assets	$253.50	$242.90
Consolidated joint ventures, mortgages	98.3	94.3
Consolidated joint ventures, other liabilities	$20.50	$15.70
Commercial Properties [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	263
Number of tenants	2,000
Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	20
Number of units	5,861
Office And Office/Flex Buildings [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	248
Aggregate square feet of the property owned or investment interest	30,400,000
Unconsolidated Joint Venture Office Buildings [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	36
Aggregate square feet of the property owned or investment interest	5,600,000
Industrial/Warehouse Facilities [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	6
Aggregate square feet of the property owned or investment interest	387,400
Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	14
Number of units	4,560
Parking/Retail [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	5
Aggregate square feet of the property owned or investment interest	121,500
Unconsolidated Joint Venture Parking/Retail Buildings [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	2
Aggregate square feet of the property owned or investment interest	81,500
Unconsolidated Joint Venture Hotel [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	1
Number of units	350
Land [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	3

Significant_Accounting_Policie3

Significant Accounting Policies (Narrative) (Details) (USD $)	0 Months Ended		3 Months Ended
	Mar. 10, 2015	Dec. 09, 2014	Mar. 31, 2015	Mar. 31, 2014	Mar. 10, 2015	Dec. 31, 2014	Dec. 09, 2014
Significant Accounting Policies [Line Items]
Capitalized development and construction salaries and other related costs			$1,300,000	$900,000
Construction, tenant improvement, and development in-progress			67,900,000			62,800,000
Maximum period after cessation of major construction activity that projects are considered complete			1 year
Threshold of investment value for discontinuation of equity method accounting			0
Amortization of deferred financing costs			953,000	769,000
Write off of unamortized deferred financing costs			0	0
Deferred leasing costs			970,000	1,031,000
Deferred tax asset			15,200,000
Income taxes, material adjustment amount			0
Common stock, shares outstanding	88,918,291	88,866,652	89,127,942		88,918,291	89,076,578	88,866,652
Common units outstanding	11,036,898	11,083,876	11,036,898		11,036,898	11,083,876	11,083,876
Distributions payable, record date	6-Apr-15	6-Jan-15
Common stock dividends and common unit distributions per share	$0.15	$0.15
Restricted stock expense			313,000	3,387,000
Common stock dividends and common unit distributions payable, date	14-Apr-15	14-Jan-15
Difference between other comprehensive income and net income			0	0
Accumulated other comprehensive income			0			0
Executive Officer [Member]
Significant Accounting Policies [Line Items]
Restricted stock expense				$3,203,000

Significant_Accounting_Policie4

Significant Accounting Policies (Estimated Useful Lives Of Assets) (Details)	3 Months Ended
	Mar. 31, 2015
Minimum [Member] | Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	5 years
Minimum [Member] | Furniture, Fixtures And Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	5 years
Maximum [Member] | Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	40 years
Maximum [Member] | Furniture, Fixtures And Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	10 years

Real_Estate_Transactions_Narra

Real Estate Transactions (Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended	0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Apr. 01, 2015
	property		property
Real Estate Properties [Line Items]
Purchase price of property	$19,658,000	$14,600,000
Realized gains (losses) on disposition of rental property, net	144,000
Number of properties sold	1		16
City Square Project [Member] | Subsequent Event [Member]
Real Estate Properties [Line Items]
Number of units				370
Purchase price of property				3,100,000
Contingent consideration				1,250,000
Minimum project start period				12 months
Total project costs				88,000,000
1451 Metropolitan Drive [Member]
Real Estate Properties [Line Items]
Area of property (in square feet)	21,600
Sales proceeds	$1,100,000

Real_Estate_Transactions_Summa

Real Estate Transactions (Summary Of Income From Properties Sold) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Real Estate Properties [Line Items]
Total revenues	$153,715	$169,596
Depreciation and amortization	-40,802	-44,985
Income from properties sold	27,008	13,167
Realized gains (losses) on sales, net	144
Income (loss) from properties sold	-2,521	-15,298
Disposal Group Disposed Of By Means Other Than Sale Not Discontinued Operations [Member]
Real Estate Properties [Line Items]
Total revenues	8	14,969
Operating and other expenses	-3	-9,253
Depreciation and amortization	-2	-3,394
Income from properties sold	3	2,322
Realized gains (losses) on sales, net	144
Income (loss) from properties sold	$147	$2,322

Investments_In_Unconsolidated_2

Investments In Unconsolidated Joint Ventures (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated joint ventures	$262,052,000			$247,468,000
Amount outstanding	42,000,000			0
Management, leasing, development and other services fees	1,600,000		504,000
Accounts receivable due from unconsolidated joint ventures	1,200,000			1,000,000
Maximum exposure to loss	206,400,000
Estimated future funding commitments	76,600,000
Unconsolidated Joint Venture Office Buildings [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties	36
Unconsolidated Joint Venture Office And Retail Buildings [Member]
Schedule of Equity Method Investments [Line Items]
Area of property (in square feet)	5,700,000
Unconsolidated Joint Venture Retail Buildings [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties	2
Unconsolidated Joint Venture Multi-Family Properties [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties	14
Number of units	4,560
Unconsolidated Joint Venture Hotel [Member]
Schedule of Equity Method Investments [Line Items]
Number of units	350
Unconsolidated Joint Venture Development Projects [Member]
Schedule of Equity Method Investments [Line Items]
Number of units	1,354
Unconsolidated Joint Venture Land Parcels [Member]
Schedule of Equity Method Investments [Line Items]
Number of units	2,853
Unconsolidated Joint Ventures [Member] | Guarantee of Indebtedness of Others [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	477,000,000
Amount outstanding	250,700,000
Unconsolidated Joint Ventures [Member] | Parent Company [Member] | Guarantee of Indebtedness of Others [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	82,800,000
Amount outstanding	51,900,000
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in venture	7.50%
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in venture	85.00%
Variable Interest Entity [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated joint ventures	129,800,000
Number of VIEs	9
Office [Member] | Unconsolidated Joint Venture Land Parcels [Member]
Schedule of Equity Method Investments [Line Items]
Area of property (in square feet)	1,400,000
South Pier At Harborside [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated joint ventures		[1]
Number of units	350
Percentage of interest in venture	50.00%	[2]
Letter of credit	$4,100,000
[1]	The negative carrying amount for this venture of $1,937 and $1,854 as of March 31, 2015 and December 31, 2014, respectively, were included in accounts payable, accrued expenses and other liabilities.
[2]	Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.

Investments_In_Unconsolidated_3

Investments In Unconsolidated Joint Ventures (Summary Of Unconsolidated Joint Ventures) (Details) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015		Sep. 02, 2013	Jun. 30, 2013	Aug. 01, 2014	Dec. 31, 2014
	item
Schedule of Equity Method Investments [Line Items]
Carrying Amount	$262,052,000					$247,468,000
Property Debt, Balance	1,787,191,000
Amount outstanding	42,000,000					0
Accounts payable, accrued expenses and other liabilities	134,462,000					126,971,000
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %	7.50%
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %	85.00%
Marbella RoseGarden, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	412	[1]
Company's Effective Ownership %	24.27%	[1],[2]
Carrying Amount	15,839,000	[1]				15,779,000	[1]
Property Debt, Balance	95,000,000	[1]
Property Debt, Maturity Date	5/1/18	[1]
Property Debt, Interest Rate	4.99%	[1]
RoseGarden Monaco Holdings, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	523	[1]
Company's Effective Ownership %	15.00%	[1],[2]
Carrying Amount	1,845,000	[1]				2,161,000	[1]
Property Debt, Balance	165,000,000	[1]
Property Debt, Maturity Date	2/1/21	[1]
Property Debt, Interest Rate	4.19%	[1]
Rosewood Lafayette Holdings, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	217	[1]
Company's Effective Ownership %	25.00%	[1],[2]
Carrying Amount						62,000	[1]
Property Debt, Balance	38,478,000	[1]
Property Debt, Maturity Date	7/1/15	[1]
Property Debt, Interest Rate	4.00%	[1]
PruRose Port Imperial South 15, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	236	[1]
Company's Effective Ownership %	50.00%	[1],[2]
Property Debt, Balance	57,500,000	[1]
Property Debt, Maturity Date	9/1/20	[1]
Property Debt, Interest Rate	4.32%	[1]
Rosewood Morristown, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	130	[3],[4]
Company's Effective Ownership %	12.50%	[2],[3],[4]
Carrying Amount	5,920,000	[3],[4]				6,029,000	[3],[4]
Property Debt, Balance	46,217,000	[3],[4]
Property Debt, Maturity Date	(e)	[3],[4]
Property Debt, Interest Rate		[3],[4],[5]
Overlook Ridge JV, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	251	[1]
Company's Effective Ownership %	50.00%	[1],[2]
Property Debt, Balance	69,420,000	[1]
Property Debt, Maturity Date	(f)	[1]
Property Debt, Interest Rate		[1],[6]
Overlook Ridge JV 2C/3B, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	371	[1]
Company's Effective Ownership %	50.00%	[1],[2]
Carrying Amount	2,304,000	[1]				2,524,000	[1]
Property Debt, Balance	51,447,000	[1]
Property Debt, Maturity Date	12/26/15	[1]
Property Debt, Interest Rate, LIBOR	L+2.50	[1],[7]
Property Debt, Interest Rate, Spread Over LIBOR	2.50%	[1],[7]
Notional amount	52,000,000
Overlook Ridge JV 2C/3B, L.L.C. [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Interest Rate	3.09%
Number of extension options	2
Loan extension period	1 year
Maximum borrowing capacity	55,500,000
Notional amount			1,840,000
Overlook Ridge JV 2C/3B, L.L.C. [Member] | Construction Loan Extension Number 1 [Member]
Schedule of Equity Method Investments [Line Items]
Extension fee	0.25%
PruRose Riverwalk G, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	316	[1]
Company's Effective Ownership %	25.00%	[1],[2]
Carrying Amount	701,000	[1]				955,000	[1]
Property Debt, Balance	79,154,000	[1]
Property Debt, Maturity Date	7/15/21	[1]
Property Debt, Interest Rate	6.00%	[1],[8]
Maximum borrowing capacity	80,249,000
Elmajo Urban Renewal Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	355	[1]
Company's Effective Ownership %	7.50%	[1],[2]
Property Debt, Balance	128,100,000	[1]
Property Debt, Maturity Date	3/1/30	[1]
Property Debt, Interest Rate	4.00%	[1],[9]
Elmajo Urban Renewal Associates, L.L.C. [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	91,000,000
Crystal House Apartments Investors LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	828	[10]
Company's Effective Ownership %	25.00%	[10],[2]
Carrying Amount	27,340,000	[10]				27,051,000	[10]
Property Debt, Balance	165,000,000	[10]
Property Debt, Maturity Date	4/1/20	[10]
Property Debt, Interest Rate	3.17%	[10]
Percentage of interest in developable land	50.00%
Number of units available for development	295
Number of approved units available for development	252
Portside Master Company, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	176	[1]
Company's Effective Ownership %	38.25%	[1],[2]
Carrying Amount	1,017,000	[1]				1,747,000	[1]
Property Debt, Balance	38,990,000	[1]
Property Debt, Maturity Date	12/4/15	[1]
Property Debt, Interest Rate, LIBOR	L+2.50	[1],[11]
Property Debt, Interest Rate, Spread Over LIBOR	2.50%	[1],[11]
Portside Master Company, L.L.C. [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Number of extension options	2
Maximum borrowing capacity	42,500,000
Portside Master Company, L.L.C. [Member] | Construction Loan Extension Number 1 [Member]
Schedule of Equity Method Investments [Line Items]
Loan extension period	2 years
Extension fee	0.13%
Portside Master Company, L.L.C. [Member] | Construction Loan Extension Number 2 [Member]
Schedule of Equity Method Investments [Line Items]
Loan extension period	2 years
Extension fee	0.25%
PruRose Port Imperial South 13, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	280	[1]
Company's Effective Ownership %	20.00%	[1],[2]
Carrying Amount	815,000	[1]				1,087,000	[1]
Property Debt, Balance	56,999,000	[1]
Property Debt, Maturity Date	6/27/16	[1]
Property Debt, Interest Rate, LIBOR	L+2.15	[1],[12]
Property Debt, Interest Rate, Spread Over LIBOR	2.15%	[1],[12]
PruRose Port Imperial South 13, L.L.C. [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Interest Rate	2.79%
Maximum borrowing capacity	73,350,000
Notional amount	69,500,000			1,620,000
PruRose Port Imperial South 13, L.L.C. [Member] | Construction Loan Extension Number 1 [Member]
Schedule of Equity Method Investments [Line Items]
Loan extension period	1 year
Extension fee	0.25%
PruRose Port Imperial South 13, L.L.C. [Member] | Construction Loan Extension Number 2 [Member]
Schedule of Equity Method Investments [Line Items]
Loan extension period	6 months
Roseland/Port Imperial Partners, L.P. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	363	[1],[13]
Company's Effective Ownership %	20.00%	[1],[13],[2]
Carrying Amount	1,755,000	[1],[13]				1,800,000	[1],[13]
Property Debt, Maturity Date	-	[1],[13]
RoseGarden Marbella South, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	311
Company's Effective Ownership %	24.27%	[2]
Carrying Amount	12,920,000					11,282,000
Property Debt, Balance	43,090,000
Property Debt, Maturity Date	3/30/17
Property Debt, Interest Rate, LIBOR	L+2.25	[14]
Property Debt, Interest Rate, Spread Over LIBOR	2.25%	[14]
RoseGarden Marbella South, L.L.C. [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Number of extension options	2
Loan extension period	1 year
Extension fee	0.25%
Maximum borrowing capacity	77,400,000
Estuary Urban Renewal Unit B, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	227	[1]
Company's Effective Ownership %	7.50%	[1],[2]
Property Debt, Balance	81,900,000	[1]
Property Debt, Maturity Date	3/1/30	[1]
Property Debt, Interest Rate	4.00%	[1],[15]
Estuary Urban Renewal Unit B, LLC [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	57,000,000
RiverPark At Harrison I, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	141
Company's Effective Ownership %	36.00%	[2]
Carrying Amount	4,571,000					4,744,000
Property Debt, Balance	23,095,000
Property Debt, Maturity Date	6/27/16
Property Debt, Interest Rate, LIBOR	L+2.35	[16]
Property Debt, Interest Rate, Spread Over LIBOR	2.35%	[16]
RiverPark At Harrison I, L.L.C. [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Number of extension options	2
Loan extension period	1 year
Maximum borrowing capacity	23,400,000
RiverPark At Harrison I, L.L.C. [Member] | Construction Loan Extension Number 1 [Member]
Schedule of Equity Method Investments [Line Items]
Extension fee	0.20%
Capitol Place Mezz LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	377
Company's Effective Ownership %	50.00%	[2]
Carrying Amount	49,873,000					49,327,000
Property Debt, Balance	73,971,000
Property Debt, Maturity Date	7/1/33
Property Debt, Interest Rate	4.82%	[17]
Capitol Place Mezz LLC [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	100,700,000
Harborside Unit A Urban Renewal, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	763
Company's Effective Ownership %	85.00%	[2]
Carrying Amount	52,263,000					34,954,000
Property Debt, Maturity Date	8/1/29
Property Debt, Interest Rate	5.20%	[18]			5.20%
Maximum borrowing capacity	192,000,000
Amount outstanding	0
Harborside Unit A Urban Renewal, LLC [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	192,000,000
Maturity					1-Aug-29
RoseGarden Monaco, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	300
Company's Effective Ownership %	41.67%	[2]
Carrying Amount	1,283,000					1,283,000
Property Debt, Maturity Date	-
Grand Jersey Waterfront Urban Renewal Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	1,000
Company's Effective Ownership %	50.00%	[2]
Carrying Amount	337,000					337,000
Property Debt, Maturity Date	-
Red Bank Corporate Plaza, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	92,878
Company's Effective Ownership %	50.00%	[2]
Carrying Amount	4,081,000					3,963,000
Property Debt, Balance	15,682,000
Property Debt, Maturity Date	5/17/16
Property Debt, Interest Rate	3.99%
Property Debt, Interest Rate, LIBOR	L+3.00	[19]
Property Debt, Interest Rate, Spread Over LIBOR	3.00%	[19]
Notional amount	13,650,000
12 Vreeland Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	139,750
Company's Effective Ownership %	50.00%	[2]
Carrying Amount	5,606,000					5,620,000
Property Debt, Balance	13,679,000
Property Debt, Maturity Date	7/1/23
Property Debt, Interest Rate	2.87%
BNES Associates III [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	106,345
Company's Effective Ownership %	31.25%	[2]
Carrying Amount	2,061,000					1,993,000
Property Debt, Balance	6,603,000
Property Debt, Maturity Date	11/1/23
Property Debt, Interest Rate	4.76%
Hillsborough 206 Holdings, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	160,000
Company's Effective Ownership %	50.00%	[2]
Carrying Amount	1,962,000					1,962,000
Property Debt, Maturity Date	-
KPG-P 100 IMW JV, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	339,615
Company's Effective Ownership %	33.33%	[2]
Carrying Amount	416,000
Property Debt, Balance	61,500,000
Property Debt, Maturity Date	9/9/16
Property Debt, Interest Rate, LIBOR	L+7.00	[20]
Property Debt, Interest Rate, Spread Over LIBOR	7.00%	[20]
Number of extension options	2
Loan extension period	1 year
Amount outstanding	13,600,000
Construction reserve	25,000,000
Keystone-Penn [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	1,842,820
Company's Effective Ownership %		[2],[20],[21]
Property Debt, Balance	205,946,000
Property Debt, Maturity Date	(v)
Property Debt, Interest Rate		[22]
Keystone-Penn [Member] | Principal Balance Due August 27, 2023 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	127,600,000
Property Debt, Maturity Date	27-Aug-23
Property Debt, Interest Rate	5.11%
Keystone-Penn [Member] | Principal Balance Due August 27, 2016 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	67,921,000
Property Debt, Maturity Date	27-Aug-16
Keystone-Penn [Member] | Principal Balance Due August 27, 2016 [Member] | Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Interest Rate, Spread Over LIBOR	5.00%
Keystone-Penn [Member] | Principal Balance Due August 27, 2016 [Member] | Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Interest Rate, Spread Over LIBOR	5.75%
Keystone-Penn [Member] | Principal Balance Due August 27, 2015 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	10,425,000
Property Debt, Maturity Date	27-Aug-15
Property Debt, Interest Rate, Spread Over LIBOR	6.00%
Keystone-Penn [Member] | Keystone Property Group [Member]
Schedule of Equity Method Investments [Line Items]
Internal rate of return	15.00%
Keystone-Penn [Member] | Parent Company [Member]
Schedule of Equity Method Investments [Line Items]
Internal rate of return	10.00%
Keystone-TriState [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	1,266,384
Company's Effective Ownership %		[2],[23]
Carrying Amount	4,792,000					6,140,000
Property Debt, Balance	205,112,000
Property Debt, Maturity Date	(x)
Property Debt, Interest Rate		[24]
Capital balance in properties in which senior pari passu interest is held	4,800,000
Number of properties with senior pari passu interest	5
Keystone-TriState [Member] | Principal Balance Due July 1, 2017 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	41,240,000
Property Debt, Maturity Date	1-Jul-17
Property Debt, Interest Rate	4.95%
Keystone-TriState [Member] | Principal Balance Due September 9, 2017 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	71,172,000
Property Debt, Maturity Date	9-Sep-17
Bears interest at fixed rate range, minimum	5.65%
Bears interest at fixed rate range, maximum	6.75%
Keystone-TriState [Member] | Principal Balance Due July 6, 2024 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	14,250,000
Property Debt, Maturity Date	6-Jul-24
Property Debt, Interest Rate	4.88%
Keystone-TriState [Member] | Principal Balance Due July 6, 2044 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	63,400,000
Property Debt, Maturity Date	6-Jul-44
Property Debt, Interest Rate	4.93%
Keystone-TriState [Member] | Principal Balance Due August 6, 2044 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	15,050,000
Property Debt, Maturity Date	6-Aug-44
Property Debt, Interest Rate	4.71%
Keystone-TriState [Member] | Parent Company [Member]
Schedule of Equity Method Investments [Line Items]
Internal rate of return	10.00%
Keystone-TriState [Member] | Keystone Entities [Member]
Schedule of Equity Method Investments [Line Items]
Internal rate of return	15.00%
KPG-MCG Curtis JV, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	885,000	[25]
Company's Effective Ownership %	50.00%	[2],[25]
Carrying Amount	58,341,000	[25]				59,911,000	[25]
Property Debt, Maturity Date	(z)	[25]
Property Debt, Interest Rate		[25],[26]
Plaza VIII & IX Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	1,225,000
Company's Effective Ownership %	50.00%	[2]
Carrying Amount	3,796,000					4,022,000
Property Debt, Maturity Date	-
Roseland/North Retail, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	30,745	[1]
Company's Effective Ownership %	20.00%	[1],[2]
Carrying Amount	1,810,000	[1]				1,828,000	[1]
Property Debt, Maturity Date	-	[1]
South Pier At Harborside [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	350
Company's Effective Ownership %	50.00%	[2]
Carrying Amount		[27]
Property Debt, Balance	65,308,000	[28]
Property Debt, Maturity Date	(ab)
Property Debt, Interest Rate
Accounts payable, accrued expenses and other liabilities	1,937,000					1,854,000
Letter of credit	4,100,000
South Pier At Harborside [Member] | 6.15% Mortgage Loan Due November 2016 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	61,184,000
Property Debt, Maturity Date	Nov-16
Property Debt, Interest Rate	6.15%
South Pier At Harborside [Member] | Variable Rate Loan Due August 1, 2020 [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	4,100,000
Property Debt, Maturity Date	1-Aug-20
Bears interest at fixed rate range, minimum	6.09%
Bears interest at fixed rate range, maximum	6.62%
Letter of credit	4,100,000
Stamford SM LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %	80.00%	[2],[29]
Property Debt, Maturity Date	-	[29]
Stamford SM LLC [Member] | Mezz Loan [Member]
Schedule of Equity Method Investments [Line Items]
Collection of notes receivable	47,200,000
Stamford SM LLC [Member] | Parent Company [Member] | Mezz Loan [Member]
Schedule of Equity Method Investments [Line Items]
Collection of notes receivable	37,800,000
Other [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Amount	404,000	[30]				907,000	[30]
Property Debt, Maturity Date	-	[30]
The Shops At 40 Park Property [Member] | Rosewood Morristown, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Square Feet	50,973
Property Debt, Balance	6,500,000
Property Debt, Maturity Date	Aug-18
Property Debt, Interest Rate	3.63%
Residual ownership interest	12.50%
Additional borrowing capacity	1,000,000
Lofts At 40 Park Property [Member] | Rosewood Morristown, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	59
Property Debt, Balance	1,117,000
Property Debt, Maturity Date	Sep-15
Property Debt, Interest Rate, Spread Over LIBOR	2.50%
Indirect ownership interest	25.00%
Number of stories	5
Metropolitan Property [Member] | Rosewood Morristown, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	38,600,000
Property Debt, Maturity Date	Sep-20
Property Debt, Interest Rate	3.25%
Quarrystone I Property [Member] | Overlook Ridge JV, L.L.C. [Member] | Senior Loans [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	52,420,000
Property Debt, Maturity Date	Mar-16
Property Debt, Interest Rate, Spread Over LIBOR	2.00%
Quarrystone I Property [Member] | Overlook Ridge JV, L.L.C. [Member] | Junior Loans [Member]
Schedule of Equity Method Investments [Line Items]
Property Debt, Balance	17,000,000
Property Debt, Maturity Date	Mar-16
Property Debt, Interest Rate, Spread Over LIBOR	0.90%
Port Imperial North Land [Member] | Roseland/Port Imperial Partners, L.P. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	836
Residual ownership interest	20.00%
Letter of Credit [Member] | Quarrystone I Property [Member] | Overlook Ridge JV, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	$17,000,000
Multi-Family Properties [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units	5,861
[1]	The Company's ownership interests in this venture are subordinate to its partner's preferred capital balance and the Company is not expected to meaningfully participate in the venture's cash flows in the near term.
[2]	Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.
[3]	Through the joint venture, the Company also owns a 12.5 percent interest in a 50,973 square feet retail building ("Shops at 40 Park") and a 25 percent interest in a to-be-built 59-unit, five story multi-family rental development property ("Lofts at 40 Park").
[4]	The Company's ownership interests in this venture are subordinate to its partner's preferred capital balance and the payment of the outstanding balance remaining on a note ($975 as of March 31, 2015), and is not expected to meaningfully participate in the venture's cash flows in the near term.
[5]	Property debt balance consists of: (i) a loan, collateralized by the Metropolitan at 40 Park, with a balance of $38,600 at March 31, 2015, bears interest at 3.25 percent, matures in September 2020 and is interest only through September 2015; (ii) a loan, collateralized by the Shops at 40 Park, with a balance of $6,500 at March 31, 2015, bears interest at 3.63 percent, matures in August 2018 and is interest-only through July 2015; and (iii) a loan, collateralized by the Lofts at 40 Park, with a balance of $1,117, bears interest at LIBOR plus 250 basis points and matures in September 2015. The Shops at 40 Park mortgage loan also provides for additional borrowing proceeds of $1 million based on certain preferred thresholds being achieved.
[6]	Property debt balance consists of: (i) the senior loan, collateralized by the Quarrystone property, with a balance of $52,420 at March 31, 2015, bears interest at LIBOR plus 200 basis, matures in March 2016 and (ii) the junior loan, with a balance of $17,000, bears interest at LIBOR plus 90 basis points, matures in March 2016 and is collateralized by a $17,000 letter of credit provided by an affiliate of the partner.
[7]	The construction loan has a maximum borrowing amount of $55,500 and provides, subject to certain conditions, two one-year extension options with a fee of 25 basis points each. The joint venture has a swap agreement that fixes the all-in rate to 3.0875 percent per annum on an initial notional amount of $1,840, increasing to $52,000, for the period from September 3, 2013 to November 2, 2015.
[8]	The permanent loan has a maximum borrowing amount of $80,249.
[9]	The construction loan with a maximum borrowing amount of $91,000 converted to a permanent loan on February 27, 2015.
[10]	The Company also owns a 50 percent interest in a vacant land to accommodate the development of approximately 295 additional units of which 252 are currently approved.
[11]	The construction loan has a maximum borrowing amount of $42,500 and provides, subject to certain conditions, two two-year extension options with a fee of 12.5 basis points for the first two-year extension and 25 basis points for the second two-year extension.
[12]	The construction loan has a maximum borrowing amount of $73,350 and provides, subject to certain conditions, one-year extension option followed by a six-month extension option with a fee of 25 basis points each. The joint venture has a swap agreement that fixes the all-in rate to 2.79 percent per annum on an initial notional amount of $1,620, increasing to $69,500 for the period from July 1, 2013 to January 1, 2016.
[13]	The Company also owns a 20 percent residual interest in undeveloped land parcels: parcels 6, I, and J ("Port Imperial North Land") that can accommodate the development of 836 apartment units.
[14]	The construction loan has a maximum borrowing amount of $77,400 and provides, subject to certain conditions, two one-year extension options with a fee of 25 basis points for each year.
[15]	The construction loan with a maximum borrowing amount of $57,000 converted to a permanent loan on February 27, 2015.
[16]	The construction loan has a maximum borrowing amount of $23,400 and provides, subject to certain conditions, two one-year extension options with a fee of 20 basis points for each year.
[17]	The construction/permanent loan has a maximum borrowing amount of $100,700 with amortization starting in August 2017.
[18]	The construction/permanent loan has a maximum borrowing amount of $192,000.
[19]	The joint venture has a swap agreement that fixes the all-in rate to 3.99375 percent per annum on an initial notional amount of $13,650 and then adjusting in accordance with an amortization schedule, which is effective from October 17, 2011 through loan maturity.
[20]	The mortgage loan has two one-year extension options, subject to certain conditions, and includes a $25 million construction escrow with a balance of $13.6 million to be drawn at March 31, 2015.
[21]	The Companybs equity interests in the joint ventures will be subordinated to Keystone Entities receiving a 15 percent internal rate of return (bIRRb) after which the Company will receive a 10 percent IRR on its subordinate equity and then all profit will be split equally.
[22]	Principal balance of $127,600 bears interest at 5.114 percent and matures in August 27, 2023; principal balance of $67,921 bears interest at rates ranging from LIBOR+5.0 percent to LIBOR+5.75 percent and matures in August 27, 2016; principal balance of $10,425 bears interest at LIBOR+6.0 percent matures in August 27, 2015.
[23]	Includes the Companybs pari-passu interests of $4.8 million in five properties and Companybs subordinated equity interests to Keystone Entities receiving a 15 percent internal rate of return (bIRRb) after which the Company will receive a 10 percent IRR on its subordinate equity and then all profit will be split equally.
[24]	Principal balance of $41,240 bears interest at 4.95 percent and matures on July 1, 2017; principal balance of $71,172 bears interest at rates ranging from 5.65 percent to 6.75 percent and matures on September 9, 2017; principal balance of $14,250 bears interest at 4.88 percent and matures on July 6, 2024; principal balance of $63,400 bears interest at 4.93 percent and matures on July 6, 2044; principal balance of $15,050 bears interest at 4.71 percent and matures on August 6, 2044.
[25]	Includes undivided interests in the same manner as investments in noncontrolling partnership, pursuant to ASC 970-323-25-12.
[26]	See Note 9: Mortgages, Loans Payable and Other Obligations for debt secured by interests in these assets.
[27]	The negative carrying amount for this venture of $1,937 and $1,854 as of March 31, 2015 and December 31, 2014, respectively, were included in accounts payable, accrued expenses and other liabilities.
[28]	Balance includes: (i) mortgage loan, collateralized by the hotel property, with a balance of $61,184, bears interest at 6.15 percent and matures in November 2016, and (ii) loan with a balance of $4.1 million, bears interest at fixed rates ranging from 6.09 percent to 6.62 percent and matures in August 1, 2020. The Company posted a $4.1 million letter of credit in support of this loan, half of which is indemnified by the partner.
[29]	The joint venture collected net proceeds of $47.2 million at maturity, of which the Company received its share of $37.8 million on August 6, 2014.
[30]	The Company owns other interests in various unconsolidated joint ventures, including interests in assets previously owned and interest in ventures whose businesses are related to its core operations. These ventures are not expected to significantly impact the Company's operations in the near term.

Investments_In_Unconsolidated_4

Investments In Unconsolidated Joint Ventures (Summary Of Company's Equity In Earnings (Loss) Of Unconsolidated Joint Ventures) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	($3,529)	($1,235)
Marbella RoseGarden, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	61	-6
RoseGarden Monaco Holdings, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-317	-277
Rosewood Lafayette Holdings, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-62	-216
Rosewood Morristown, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-94	-98
Overlook Ridge JV 2C/3B, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-220	62
PruRose Riverwalk G, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-254	-538
Elmajo Urban Renewal Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures		-112
Crystal House Apartments Investors LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-10	-327
Portside Master Company, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-719	-213
PruRose Port Imperial South 13, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-225	-206
Roseland/Port Imperial Partners, L.P. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-184	-164
Estuary Urban Renewal Unit B, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures		-15
RiverPark At Harrison I, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-173
Capitol Place Mezz LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	75
Grand Jersey Waterfront Urban Renewal Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-19	-37
Red Bank Corporate Plaza, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	110	99
12 Vreeland Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-14	89
BNES Associates III [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	68	36
Hillsborough 206 Holdings, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures		-5
KPG-P 100 IMW JV, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-384	-653
Keystone-TriState [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-1,348
KPG-MCG Curtis JV, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	196
Plaza VIII & IX Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	86	102
Roseland/North Retail, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-18	-24
South Pier At Harborside [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures	-84	398
Stamford SM LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures		916
Other [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures		($46)

Investments_In_Unconsolidated_5

Investments In Unconsolidated Joint Ventures (Summary Of Financial Position Of Unconsolidated Joint Ventures) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Investments In Unconsolidated Joint Ventures [Abstract]
Rental property, net	$1,546,589	$1,534,812
Other assets	410,410	398,222
Total assets	1,956,999	1,933,034
Mortgages and loans payable	1,162,732	1,060,020
Other liabilities	214,572	211,340
Partners'/members' capital	579,695	661,674
Total liabilities and partners'/members' capital	$1,956,999	$1,933,034

Investments_In_Unconsolidated_6

Investments In Unconsolidated Joint Ventures (Summary Of Results Of Operations Of Unconsolidated Joint Ventures) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Investments In Unconsolidated Joint Ventures [Abstract]
Total revenues	$74,477	$30,993
Operating and other expenses	-57,356	-18,353
Depreciation and amortization	-16,993	-8,368
Interest expense	-11,334	-6,341
Net loss	($11,206)	($2,069)

Deferred_Charges_Goodwill_And_2

Deferred Charges, Goodwill And Other Assets (Schedule Of Deferred Charges, Goodwill And Other Assets) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Deferred Charges, Goodwill And Other Assets [Line Items]
Deferred leasing costs	$226,649			$239,138
Deferred financing costs	20,755			24,042
Deferred charges, gross	247,404			263,180
Accumulated amortization	-107,601			-122,358
Deferred charges, net	139,803			140,822
Notes receivable	21,430	[1]		21,491	[1]
In-place lease values, related intangible and other assets, net	6,021			6,565
Goodwill	2,945			2,945
Prepaid expenses and other assets, net	40,561			32,827
Total deferred charges, goodwill and other assets	210,760			204,650
Lease revenue	123,793		134,051
Mortgage Receivable [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Notes receivable	10,400
Spread over LIBOR	6.00%
8% Notes Receivable [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Notes receivable	7,800
Interest rate	8.00%
Interest-Free Notes Receivable [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Notes receivable	$3,300
[1]	Includes as of March 31, 2015: a mortgage receivable for $10.4 million which bears interest at LIBOR plus six percent and matures in August 2015; a note receivable for $7.8 million which bears interest at eight percent and matures in October 2017 (which was repaid in full to the Company on April 15, 2015); and an interest-free note receivable with a net present value of $3.3 million and matures in April 2023. The Company believes these balances are fully collectible.

Recovered_Sheet1

Deferred Charges, Goodwill and Other Assets (Summary Of Notional Amount And Fair Value Of Derivative Financial Instruments) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Fair Value	$32,000			$95,000
Interest and other investment income (loss)	267,000		386,000
Gain (Loss) on Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Interest and other investment income (loss)	-63,000
LIBOR Cap One [Member]
Derivatives, Fair Value [Line Items]
Notional Value	51,000,000	[1]
Strike Rate	1.50%
Effective Date	1-Sep-14
Expiration Date	1-Oct-15
Fair Value	1,000			1,000
LIBOR Cap Two [Member]
Derivatives, Fair Value [Line Items]
Notional Value	24,000,000	[1]
Strike Rate	1.50%
Effective Date	1-Sep-14
Expiration Date	1-Oct-15
Fair Value	1,000			1,000
LIBOR Cap Three [Member]
Derivatives, Fair Value [Line Items]
Notional Value	51,000,000	[1]
Strike Rate	1.75%
Effective Date	1-Oct-15
Expiration Date	1-Oct-16
Fair Value	20,000			64,000
LIBOR Cap Four [Member]
Derivatives, Fair Value [Line Items]
Notional Value	24,000,000	[1]
Strike Rate	1.75%
Effective Date	1-Oct-15
Expiration Date	1-Oct-16
Fair Value	$10,000			$29,000
[1]	The notional value is an indication of the extent of our involvement in these instruments at that time, but does not represent exposure to credit, interest rate or market risks.

Restricted_Cash_Details

Restricted Cash (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Restricted Cash [Abstract]
Security deposits	$7,868	$7,795
Escrow and other reserve funds	27,912	26,450
Total restricted cash	$35,780	$34,245

Senior_Unsecured_Notes_Summary

Senior Unsecured Notes (Summary Of Senior Unsecured Notes) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Debt Instrument [Line Items]
Senior Unsecured Notes	$1,268,018		$1,267,744
5.800% Senior Unsecured Notes, Due January 15, 2016 [Member]
Debt Instrument [Line Items]
Senior Unsecured Notes	200,066		200,086
Effective Rate	5.81%	[1]
Interest rate of senior unsecured notes	5.80%
Maturity date of the senior unsecured notes	15-Jan-16
2.500% Senior Unsecured Notes Due December 15, 2017 [Member]
Debt Instrument [Line Items]
Senior Unsecured Notes	249,224		249,150
Effective Rate	2.80%	[1]
Interest rate of senior unsecured notes	2.50%
Maturity date of the senior unsecured notes	15-Dec-17
7.750% Senior Unsecured Notes, Due August 15, 2019 [Member]
Debt Instrument [Line Items]
Senior Unsecured Notes	249,066		249,013
Effective Rate	8.02%	[1]
Interest rate of senior unsecured notes	7.75%
Maturity date of the senior unsecured notes	15-Aug-19
4.500% Senior Unsecured Notes Due April 18, 2022 [Member]
Debt Instrument [Line Items]
Senior Unsecured Notes	299,580		299,565
Effective Rate	4.61%	[1]
Interest rate of senior unsecured notes	4.50%
Maturity date of the senior unsecured notes	18-Apr-22
3.150% Senior Unsecured Note, Due May 15, 2023 [Member]
Debt Instrument [Line Items]
Senior Unsecured Notes	$270,082		$269,930
Effective Rate	3.52%	[1]
Interest rate of senior unsecured notes	3.15%
Maturity date of the senior unsecured notes	15-May-23
[1]	Includes the cost of terminated treasury lock agreements (if any), offering and other transaction costs and the discount/premium on the notes, as applicable.

Unsecured_Revolving_Credit_Fac2

Unsecured Revolving Credit Facility (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
	entity
	item
Line of Credit Facility [Line Items]
Outstanding borrowings under the facility	$42,000,000	$0
Unsecured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Number of lending institutions	17
Borrowing capacity under the credit facility	600,000,000
Expandable borrowing capacity under the credit facility	1,000,000,000
Credit facility maturity date	1-Jul-17
Number of extension options	2
Credit facility, extension period	6 months
Line of credit facility, bid feature, current borrowing capacity	$300,000,000
Terms of the unsecured facility	The terms of the unsecured facility include certain restrictions and covenants which limit, among other things the incurrence of additional indebtedness, the incurrence of liens and the disposition of real estate properties (to the extent that: (i) such property dispositions cause the Company to default on any of the financial ratios of the facility described below, or (ii) the property dispositions are completed while the Company is under an event of default under the facility, unless, under certain circumstances, such disposition is being carried out to cure such default), and which require compliance with financial ratios relating to the maximum leverage ratio (60 percent), the maximum amount of secured indebtedness (40 percent), the minimum amount of fixed charge coverage (1.5 times), the maximum amount of unsecured indebtedness (60 percent), the minimum amount of unencumbered property interest coverage (2.0 times) and certain investment limitations (generally 15 percent of total capitalization).
Terms of dividend restriction	If an event of default has occurred and is continuing, the Company will not make any excess distributions except to enable the Company to continue to qualify as a REIT under the Code. The Company was in compliance with its debt covenants under its revolving credit facility as of March 31, 2015.
Unsecured Revolving Credit Facility Extension 1 [Member]
Line of Credit Facility [Line Items]
Credit facility extension fee, basis points	0.08%
Unsecured Revolving Credit Facility Extension 2 [Member]
Line of Credit Facility [Line Items]
Credit facility extension fee, basis points	0.08%
Minimum [Member] | Unsecured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Fixed charge coverage ratio	1.5
Unencumbered property interest coverage	2
Maximum [Member] | Unsecured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Leverage ratio	60.00%
Secured indebtedness	40.00%
Unsecured indebtedness	60.00%
Investment limitations as a percentage of total capitalization	15.00%

Unsecured_Revolving_Credit_Fac3

Unsecured Revolving Credit Facility (Change In The Operating Partnership's Unsecured Debt Ratings) (Details) (Unsecured Revolving Credit Facility [Member])	3 Months Ended
	Mar. 31, 2015
No Ratings Or Less Than Baa3 [Member] | No Ratings Or Less Than BBB- [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings	No ratings or less than BBB-/Baa3
Interest Rate - Applicable Basis Points Above LIBOR	1.70%
Facility Fee Basis Points	0.35%
Baa3 [Member] | BBB- [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings	BBB- or Baa3 (current)
Interest Rate - Applicable Basis Points Above LIBOR	1.30%
Facility Fee Basis Points	0.30%
Baa2 [Member] | BBB [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings	BBB or Baa2
Interest Rate - Applicable Basis Points Above LIBOR	1.10%
Facility Fee Basis Points	0.20%
Baa1 [Member] | BBB+ [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings	BBB+ or Baa1
Interest Rate - Applicable Basis Points Above LIBOR	1.00%
Facility Fee Basis Points	0.15%
A3 Or Higher [Member] | A- Or Higher [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings	A- or A3 or higher
Interest Rate - Applicable Basis Points Above LIBOR	0.93%
Facility Fee Basis Points	0.13%

Mortgages_Loans_Payable_And_Ot2

Mortgages, Loans Payable And Other Obligations (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
	property
Debt Instrument [Line Items]
Number of properties with encumbered company mortgages	28
Book value of encumbered properties	$968,000,000
Cash paid for interest	25,922,000	36,119,000
Interest capitalized	3,607,000	3,141,000
Total indebtedness	2,107,572,000		2,088,654,000
Total indebtedness, weighted average interest rate	5.65%		5.64%
Revolving Credit Facility Borrowing And Other Variable Rate Mortgage Debt [Member]
Debt Instrument [Line Items]
Total indebtedness	179,795,000		159,860,000
Total indebtedness, weighted average interest rate	3.33%		3.83%
Fixed Rate Debt And Other Obligations [Member]
Debt Instrument [Line Items]
Total indebtedness	1,927,777,000		1,928,794,000
Total indebtedness, weighted average interest rate	5.87%		5.79%
Unconsolidated Joint Venture [Member]
Debt Instrument [Line Items]
Interest capitalized	$1,256,000	$918,000

Mortgages_Loans_Payable_And_Ot3

Mortgages, Loans Payable And Other Obligations (Summary Of Mortgages, Loans Payable And Other Obligations) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Debt Instrument [Line Items]
Mortgages, loans payable and other obligations	$797,554		$820,910
Overlook - Site IIID, IIIC, IIIA [Member]
Debt Instrument [Line Items]
Property Name	Overlook - Site IIID,IIIC, IIIA (b)	[1]
Lender	Wells Fargo Bank N.A.	[1]
LIBOR	LIBOR+3.50	[1],[2]
Property Debt, Interest Rate, Spread Over LIBOR	3.50%
Mortgages, loans payable and other obligations		[1]	17,260	[1]
Overlook - Site IIB [Member]
Debt Instrument [Line Items]
Property Name	Overlook - Site IIB (Quarrystone I) (b)	[1]
Lender	Wells Fargo Bank N.A.	[1]
LIBOR	LIBOR+2.50	[1],[2]
Property Debt, Interest Rate, Spread Over LIBOR	2.50%
Mortgages, loans payable and other obligations		[1]	5,787	[1]
6 Becker, 85 Livingston, 75 Livingston & 20 Waterview [Member]
Debt Instrument [Line Items]
Property Name	6 Becker, 85 Livingston, 75 Livingston & 20 Waterview	[3]
Lender	Wells Fargo CMBS	[3]
Effective Rate	10.26%	[2],[3]
Mortgages, loans payable and other obligations	65,035	[3]	65,035	[3]
Maturity	11-Aug-14	[3],[4]
Number of properties used to collateralized mortgage	4
4 Sylvan [Member]
Debt Instrument [Line Items]
Property Name	4 Sylvan
Lender	Wells Fargo CMBS
Effective Rate	10.26%	[2]
Mortgages, loans payable and other obligations	14,575		14,575
Maturity	11-Aug-14	[4]
10 Independence [Member]
Debt Instrument [Line Items]
Property Name	10 Independence
Lender	Wells Fargo CMBS
Effective Rate	10.26%	[2]
Mortgages, loans payable and other obligations	16,924		16,924
Maturity	11-Aug-14	[4]
9200 Edmonston Road [Member]
Debt Instrument [Line Items]
Property Name	9200 Edmonston Road (e)	[5]
Lender	Principal Commercial Funding L.L.C.	[5]
Effective Rate	5.53%	[2],[5]
Mortgages, loans payable and other obligations	3,903	[5]	3,951	[5]
Maturity	1-May-15	[5]
Port Imperial South [Member]
Debt Instrument [Line Items]
Property Name	Port Imperial South
Lender	Wells Fargo Bank N.A.
LIBOR	LIBOR+1.75	[2]
Property Debt, Interest Rate, Spread Over LIBOR	1.75%
Mortgages, loans payable and other obligations	44,333		44,119
Maturity	19-Sep-15
4 Becker [Member]
Debt Instrument [Line Items]
Property Name	4 Becker
Lender	Wells Fargo CMBS
Effective Rate	9.55%	[2]
Mortgages, loans payable and other obligations	39,568		39,421
Maturity	11-May-16
5 Becker [Member]
Debt Instrument [Line Items]
Property Name	5 Becker (f)	[6]
Lender	Wells Fargo CMBS	[6]
Effective Rate	19.45%	[2],[6]
Mortgages, loans payable and other obligations	14,073	[6]	13,867	[6]
Maturity	11-May-16	[6]
210 Clay [Member]
Debt Instrument [Line Items]
Property Name	210 Clay (g)	[7]
Lender	Wells Fargo CMBS	[7]
Effective Rate	18.10%	[2],[7]
Mortgages, loans payable and other obligations	13,549	[7]	13,330	[7]
Maturity	11-May-16	[7]
Curtis Center [Member]
Debt Instrument [Line Items]
Property Name	Curtis Center (h)	[8]
Lender	CCRE & PREFG	[8]
LIBOR	LIBOR+5.912	[2],[8],[9]
Property Debt, Interest Rate, Spread Over LIBOR	5.91%
Mortgages, loans payable and other obligations	64,000	[8]	64,000	[8]
Maturity	9-Oct-16	[8]
Percentage of interest in venture	50.00%
Number of extension options	3
Loan extension period	1 year
Deferred financing costs amortization interest rate	1.36%
Curtis Center [Member] | Senior Loan [Member]
Debt Instrument [Line Items]
Effective Rate	3.47%
Property Debt, Interest Rate, Spread Over LIBOR	3.29%
Mortgages, loans payable and other obligations	102,000
Percentage of interest in loan	50.00%
LIBOR measurement period	1 month
Curtis Center [Member] | Mezzanine Loan [Member]
Debt Instrument [Line Items]
Effective Rate	9.68%
Property Debt, Interest Rate, Spread Over LIBOR	9.50%
Mortgages, loans payable and other obligations	26,000
Percentage of interest in loan	50.00%
Maximum borrowing capacity	48,000
LIBOR measurement period	1 month
Various [Member]
Debt Instrument [Line Items]
Property Name	Various (i)	[10]
Lender	Prudential Insurance	[10]
Effective Rate	6.33%	[10],[2]
Mortgages, loans payable and other obligations	145,058	[10]	145,557	[10]
Maturity	15-Jan-17	[10]
Number of properties used to collateralized mortgage	7
150 Main St [Member]
Debt Instrument [Line Items]
Property Name	150 Main St.
Lender	Webster Bank
LIBOR	LIBOR+2.35	[2]
Property Debt, Interest Rate, Spread Over LIBOR	2.35%
Mortgages, loans payable and other obligations	1,963		1,193	[11]
Maturity	30-Mar-17
Maximum borrowing capacity	28,800
23 Main Street [Member]
Debt Instrument [Line Items]
Property Name	23 Main Street
Lender	JPMorgan CMBS
Effective Rate	5.59%	[2]
Mortgages, loans payable and other obligations	29,041		29,210
Maturity	1-Sep-18
Harborside Plaza 5 [Member]
Debt Instrument [Line Items]
Property Name	Harborside Plaza 5
Lender	The Northwestern Mutual Life Insurance Co. & New York Life Insurance Co.
Effective Rate	6.84%	[2]
Mortgages, loans payable and other obligations	220,630		221,563
Maturity	1-Nov-18
100 Walnut Avenue [Member]
Debt Instrument [Line Items]
Property Name	100 Walnut Avenue
Lender	Guardian Life Insurance Co.
Effective Rate	7.31%	[2]
Mortgages, loans payable and other obligations	18,476		18,542
Maturity	1-Feb-19
One River Center [Member]
Debt Instrument [Line Items]
Property Name	One River Center (j)	[12]
Lender	Guardian Life Insurance Co.	[12]
Effective Rate	7.31%	[12],[2]
Mortgages, loans payable and other obligations	42,326	[12]	42,476	[12]
Maturity	1-Feb-19	[12]
Number of properties used to collateralized mortgage	3
Park Square [Member]
Debt Instrument [Line Items]
Property Name	Park Square
Lender	Wells Fargo Bank N.A.
LIBOR	LIBOR+1.872	[13],[2]
Property Debt, Interest Rate, Spread Over LIBOR	1.87%
Mortgages, loans payable and other obligations	27,500		27,500
Maturity	10-Apr-19
Deferred financing costs amortization interest rate	0.12%
Port Imperial South 4/5 Retail [Member]
Debt Instrument [Line Items]
Property Name	Port Imperial South 4/5 Retail
Lender	American General Life & A/G PC
Effective Rate	4.56%	[2]
Mortgages, loans payable and other obligations	4,000		4,000
Maturity	1-Dec-21
Port Imperial South 4/5 Garage [Member]
Debt Instrument [Line Items]
Property Name	Port Imperial South 4/5 Garage
Lender	American General Life & A/G PC
Effective Rate	4.85%	[2]
Mortgages, loans payable and other obligations	$32,600		$32,600
Maturity	1-Dec-29
[1]	On March 27, 2015, the Company repaid these loans at par, using borrowings on the Company's unsecured revolving credit facility.
[2]	Reflects effective rate of debt, including deferred financing costs, comprised of the cost of terminated treasury lock agreements (if any), debt initiation costs, mark-to-market adjustment of acquired debt and other transaction costs, as applicable.
[3]	Mortgage is cross collateralized by the four properties.
[4]	The loan was not repaid at maturity and the Company has begun discussions with the lender regarding a potential deed-in-lieu of foreclosure in satisfaction of the obligation.
[5]	The mortgage loan originally matured on May 1, 2013. The maturity date was extended until May 1, 2015 with the same interest rate. Excess cash flow, as defined, is being held by the lender for re-leasing costs. The deed for the property was placed in escrow and is available to the lender in the event of default or non-payment at maturity.
[6]	The cash flow from this property is insufficient to cover operating costs and debt service. Consequently, the Company notified the lender and suspended debt service payments in August 2013. The Company has begun discussions with the lender regarding a deed-in-lieu of foreclosure and began remitting available cash flow to the lender effective August 2013.
[7]	The cash flow from this property is insufficient to cover operating costs and debt service. Consequently, the Company notified the lender and suspended debt service payments in January 2015.
[8]	The Company owns a 50 percent tenants-in-common interest in the Curtis Center property. The Companybs $64.0 million loan consists of its 50 percent interest in a $102 million senior loan with a current rate of 3.469 percent at March 31, 2015 and its 50 percent interest in a $26 million mezzanine loan (with a maximum borrowing capacity of $48 million) with a current rate of 9.675 percent at March 31, 2015. The senior loan rate is based on a floating rate of one-month LIBOR plus 329 basis points and the mezzanine loan rate is based on a floating rate of one-month LIBOR plus 950 basis points. The Company has entered into LIBOR caps for the periods of the loans. The loans provide for three one-year extension options.
[9]	The effective interest rate includes amortization of deferred financing costs of 1.362 percent.
[10]	Mortgage is cross collateralized by seven properties. The Company has agreed, subject to certain conditions, to guarantee repayment of a portion of the loan.
[11]	This construction loan has a maximum borrowing capacity of $28.8 million.
[12]	Mortgage is collateralized by the three properties comprising One River Center.
[13]	The effective interest rate includes amortization of deferred financing costs of 0.122 percent.

Employee_Benefit_401k_Plans_An1

Employee Benefit 401(k) Plans And Deferred Retirement Compensation Agreements (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Minimum employee subscription rate, percentage of compensation	1.00%
Maximum employee subscription rate, percentage of compensation	60.00%
Employee pre-tax contributions vested percentage	100.00%
Vesting rate	20.00%
Percentage vested after total service period	100.00%
Employees' vesting rights	Participants are always 100 percent vested in their pre-tax contributions and will begin vesting in any matching or profit sharing contributions made on their behalf after two years of service with the Company at a rate of 20 percent per year, becoming 100 percent vested after a total of six years of service with the Company.
Expenses for employee benefit plan	$0	$25,000
Minimum [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer contribution vesting period	2 years
Maximum [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer contribution vesting period	6 years
Messr Lefkowitz And Messr Thomas [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Expenses for employee benefit plan	1,200,000
Messr Hersh [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Expenses for employee benefit plan	2,300,000
Deferred Retirement Compensation Units [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Expenses for employee benefit plan	$0	$1,200,000

Disclosure_Of_Fair_Value_Of_Fi1

Disclosure Of Fair Value Of Financial Instruments (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Disclosure Of Fair Value Of Financial Instruments [Abstract]
Fair value of Company's long-term debt	$2,125,451,000	$2,133,214,000
Book value of Company's long-term debt	$2,107,572,000	$2,088,654,000

Commitments_And_Contingencies_1

Commitments And Contingencies (Tax Abatement Agreements) (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Harborside Financial Center Plaza 4-A [Member]
Commitments And Contingencies [Line Items]
Project period	20 years
Percentage of PILOT on project costs	2.00%
Total project costs	$49,500,000
Payments in lieu of property taxes (PILOT)	247,000	247,000
Harborside Financial Center Plaza 5 [Member]
Commitments And Contingencies [Line Items]
Project period	20 years
Percentage of PILOT on project costs	2.00%
Total project costs	170,900,000
Payments in lieu of property taxes (PILOT)	$854,000	$854,000
Port Imperial South 4/5 Garage [Member]
Commitments And Contingencies [Line Items]
Project period	5 years
Period of real estate taxes phase in	5 years
Park Square [Member]
Commitments And Contingencies [Line Items]
Period of partial abatement of real estate taxes	4 years

Commitments_And_Contingencies_2

Commitments And Contingencies (Ground Lease Agreements) (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Commitments And Contingencies [Abstract]
Ground lease expense incurred	$102,000	$102,000

Commitments_And_Contingencies_3

Commitments And Contingencies (Roseland Contingent Consideration) (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Oct. 23, 2012
Roseland Partners, L.L.C. [Member]
Business Acquisition, Contingent Consideration [Line Items]
Fair value of contingent consideration		$10,000,000
Business acquisition, contingent cash payment	900,000
Purchase accounting adjustments	0
Completion/Start Of Certain Developments [Member] | Minimum [Member]
Business Acquisition, Contingent Consideration [Line Items]
Probability of occurrence	92.00%
Completion/Start Of Certain Developments [Member] | Maximum [Member]
Business Acquisition, Contingent Consideration [Line Items]
Probability of occurrence	99.00%
Obtaining Of Tax Credits/Grants [Member]
Business Acquisition, Contingent Consideration [Line Items]
Probability of occurrence	50.00%
Obtaining Of Tax Credits/Grants [Member] | Roseland Partners, L.L.C. [Member]
Business Acquisition, Contingent Consideration [Line Items]
Business acquisition, contingent cash payment	$3,000,000

Commitments_And_Contingencies_4

Commitments And Contingencies (Departure Of Executive Officers) (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended	0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014	11-May-15	Dec. 31, 2014
				item
Commitments And Contingencies [Line Items]
Severance benefits	$23,800,000	$11,000,000
Restricted stock units vested	37,392
Accounts payable, accrued expenses and other liabilities	134,462,000				126,971,000
Employee Severance [Member]
Commitments And Contingencies [Line Items]
Accounts payable, accrued expenses and other liabilities	11,600,000				11,600,000
Messr Lefkowitz [Member]
Commitments And Contingencies [Line Items]
Severance benefits	3,400,000
Stock options vested	11,457
Restricted stock units vested	68,667
Period for continuation of health insurance	48 months
Messr Thomas [Member]
Commitments And Contingencies [Line Items]
Severance benefits	3,100,000
Stock options vested	33,605
Restricted stock units vested	41,000
Period for continuation of health insurance	48 months
Consulting payment			300,000
Scenario, Forecast [Member] | Messr Hersh [Member]
Commitments And Contingencies [Line Items]
Severance benefits				8,000,000
Restricted stock units vested				210,000
Period for continuation of health insurance				48 months
Cash payment				504,000
Termination payment multiplier				210,000
Shares issued				41,811
Deferred retirement compensation contribution				$2,311,792
Total Stockholder Return Based Awards [Member]
Commitments And Contingencies [Line Items]
Restricted stock units vested	357
Shares issued	45,062
Total Stockholder Return Based Awards [Member] | Scenario, Forecast [Member]
Commitments And Contingencies [Line Items]
Restricted stock units vested				675
Shares issued				41,811
Total Stockholder Return Based Awards [Member] | Scenario, Forecast [Member] | Messr Hersh [Member]
Commitments And Contingencies [Line Items]
Restricted stock units vested				675

Commitments_And_Contingencies_5

Commitments And Contingencies (Roseland Transaction Modifications) (Narrative) (Details) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Oct. 28, 2014	Oct. 23, 2015	Apr. 24, 2015	Dec. 31, 2014
Commitments And Contingencies [Line Items]
Severance benefits	$23,800,000	$11,000,000
Earn out paid		3,936,000
Accounts payable, accrued expenses and other liabilities	134,462,000					126,971,000
Minimum [Member]
Commitments And Contingencies [Line Items]
Percentage of interest in venture	7.50%
Roseland Partners, L.L.C. [Member]
Commitments And Contingencies [Line Items]
Business acquisition, contingent cash payment	900,000
Accounts payable, accrued expenses and other liabilities	1,000,000					1,000,000
Roseland Partners, L.L.C. [Member] | Messr Goldberg [Member]
Commitments And Contingencies [Line Items]
Consulting period	1 year
Roseland Partners, L.L.C. [Member] | Messr Klatt And Messr Goldberg [Member]
Commitments And Contingencies [Line Items]
Period for continuation of health insurance	1 year
Severance benefits			750,000
Roseland Partners, L.L.C. [Member] | Messr Tycher [Member] | Minimum [Member]
Commitments And Contingencies [Line Items]
Percentage of interest in venture	50.00%
Roseland Partners, L.L.C. [Member] | Scenario, Forecast [Member] | Messr Goldberg [Member]
Commitments And Contingencies [Line Items]
Consulting payment				400,000
Roseland Partners, L.L.C. [Member] | Scenario, Forecast [Member] | Messr Klatt And Messr Goldberg [Member]
Commitments And Contingencies [Line Items]
Severance benefits					500,000
Roseland Partners, L.L.C. [Member] | Obtaining Of Tax Credits/Grants [Member]
Commitments And Contingencies [Line Items]
Business acquisition, contingent cash payment	3,000,000
Roseland Partners, L.L.C. [Member] | Obtaining Of Tax Credits/Grants [Member] | Scenario, Forecast [Member]
Commitments And Contingencies [Line Items]
Earn out paid	$1,000,000

Commitments_And_Contingencies_6

Commitments And Contingencies (Other) (Narrative) (Details) (USD $)	3 Months Ended			0 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Aug. 01, 2014	Apr. 01, 2015	Dec. 31, 2014
Commitments And Contingencies [Line Items]
Amount outstanding	$42,000,000					$0
Investment in unconsolidated joint ventures	20,880,000		1,889,000
Development of rental property	12,519,000		7,357,000
Purchase price of property	19,658,000		14,600,000
Eastchester Project [Member]
Commitments And Contingencies [Line Items]
Percentage of interest in venture	76.25%
Number of units	108
Project costs incurred to date	15,400,000
Amount of project costs funded by members	20,900,000
Total project costs	50,000,000
Property Lock-Ups [Member]
Commitments And Contingencies [Line Items]
Number of properties	7
Properties aggregate net book value	124,600,000
Expiration year	2016
Property Lock-Ups Expired [Member]
Commitments And Contingencies [Line Items]
Number of properties	110
Properties aggregate net book value	1,300,000,000
Harborside Unit A Urban Renewal, LLC [Member]
Commitments And Contingencies [Line Items]
Percentage of interest in venture	85.00%	[1]
Development costs	88,800,000
Number of units	763
Maximum borrowing capacity	192,000,000
Amount outstanding	0
Interest rate	5.20%	[2]		5.20%
Harborside Unit A Urban Renewal, LLC [Member] | Harborside Residential Project [Member]
Commitments And Contingencies [Line Items]
Total project costs	320,000,000
Harborside Unit A Urban Renewal, LLC [Member] | Construction Loan [Member]
Commitments And Contingencies [Line Items]
Maximum borrowing capacity	192,000,000
Mortgage loan, maturity date				1-Aug-29
Harborside Unit A Urban Renewal, LLC [Member] | Parent Company [Member]
Commitments And Contingencies [Line Items]
Total project costs	42,200,000
150 Main Street, L.L.C. [Member] | Construction Loan [Member] | Eastchester Project [Member]
Commitments And Contingencies [Line Items]
Maximum borrowing capacity	28,800,000
Amount outstanding	2,000,000
Wegmans Food Markets, Inc. [Member]
Commitments And Contingencies [Line Items]
Costs of the project incurred	9,300,000
Delivery date to tenant	2016
Area of property (in square feet)	140,000
Wegmans Food Markets, Inc. [Member] | Scenario, Forecast [Member]
Commitments And Contingencies [Line Items]
Total project costs	25,300,000
Multi-Family Properties [Member]
Commitments And Contingencies [Line Items]
Number of units	5,861
Subsequent Event [Member] | City Square Project [Member]
Commitments And Contingencies [Line Items]
Number of units					370
Total project costs					88,000,000
Purchase price of property					3,100,000
Contingent consideration					$1,250,000
Minimum project start period					12 months
[1]	Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.
[2]	The construction/permanent loan has a maximum borrowing amount of $192,000.

Commitments_And_Contingencies_7

Commitments And Contingencies (Future Minimum Rental Payments Of Ground Leases) (Details) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Commitments And Contingencies [Abstract]
April 1 through December 31, 2015	$278
2016	371
2017	267
2018	232
2019	235
2020 through 2084	15,584
Total	$16,967

Tenant_Leases_Details

Tenant Leases (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Property Subject to or Available for Operating Lease [Line Items]
April 1 through December 31, 2015	342,120
2016	432,644
2017	381,749
2018	301,126
2019	245,082
2020 and thereafter	982,973
Total	2,685,694
Tenant Leases [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating leases with various expiration dates through year	31-Dec-35
Multi-Family Properties [Member]
Property Subject to or Available for Operating Lease [Line Items]
Lease period	1 year

MackCali_Realty_Corporation_St2

Mack-Cali Realty Corporation Stockholders' Equity (Share Repurchase Program And Dividend Reinvestment And Stock Purchase Plan) (Narrative) (Details) (USD $)	3 Months Ended	31 Months Ended
	Mar. 31, 2015	Mar. 31, 2015
Stockolders Equity [Line Items]
Date share repurchase program was initiated	Sep-12
Capacity of share repurchase program	$150,000,000	$150,000,000
Shares purchased and retired		394,625
Aggregate cost of stock repurchased		11,000,000
Capacity available for additional repurchase of outstanding common stock	139,000,000	139,000,000
Dividend Reinvestment And Stock Purchase Plan [Member]
Stockolders Equity [Line Items]
Common stock reserved for future issuance	5,500,000	5,500,000
Monthly cash investment without restriction, maximum	$5,000

MackCali_Realty_Corporation_St3

Mack-Cali Realty Corporation Stockholders' Equity (Stock Options Plans) (Narrative) (Details) (USD $)	3 Months Ended			12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2014	31-May-13	31-May-04
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option terms	10 years
Weighted average remaining contractual life	4 years 8 months 12 days			4 years 10 months 24 days
Options exercised	0	0
Stock options expense	$1,000		$1,000
2013 Incentive Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved stocks for issuance					4,600,000
2004 Incentive Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved stocks for issuance						2,500,000
Shares issued	0
Employee And Director Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved stocks for issuance	2,700,000
Employee And Director Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved stocks for issuance	4,350,000
2000 Employee Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable time period	5 years
2000 Employee Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved stocks for issuance	2,500,000
2000 Employee Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved stocks for issuance	4,000,000
2000 Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable time period	1 year
2000 Director Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved stocks for issuance	200,000
2000 Director Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved stocks for issuance	350,000

MackCali_Realty_Corporation_St4

Mack-Cali Realty Corporation Stockholders' Equity (Restricted Stock Awards And TSR-Based Awards) (Narrative) (Details) (USD $)	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015	Sep. 12, 2012	Mar. 31, 2014	Sep. 11, 2012	Dec. 31, 2013	11-May-15	Dec. 31, 2014
	item
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executive officers who departed	2
Shares vested	37,392
Unvested restricted stock outstanding	313,337						346,946
Awards issued	3,786
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock outstanding	103,337		414,483
Restricted stock awards unvested shares outstanding, performance contingent	210,000
Awards issued		319,667
Restricted Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation vesting period	1 year
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation vesting period	7 years
Ratified Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested			109,667
Ratified Restricted Stock Awards [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation vesting period	5 years
Ratified Restricted Stock Awards [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation vesting period	7 years
Total Stockholder Return Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation vesting period	4 years
Shares vested	357
Shares granted and vested	528
Awards issued				5,160	1,032
Value of common stock received upon vesting of awards	1,000
Shares issued	45,062
Total unrecognized compensation cost	1.2
Total unrecognized compensation cost, period of recognition	1 year 3 months 18 days
Scenario, Forecast [Member] | Ratified Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested						84,000
Shares granted and vested						126,000
Scenario, Forecast [Member] | Total Stockholder Return Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested						675
Shares issued						41,811

MackCali_Realty_Corporation_St5

Mack-Cali Realty Corporation Stockholders' Equity (Deferred Stock Compensation Plan For Directors) (Narrative) (Details)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]
Maximum percentage of retainer fee that directors may defer	100.00%
Deferred stock units earned	5,002	5,707
Deferred stock units outstanding	162,761		157,730

MackCali_Realty_Corporation_St6

Mack-Cali Realty Corporation Stockholders' Equity (Earnings Per Share) (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anti-dilutive securities excluded from the computation of earnings per share	10,000	15,000
Dividends declared per common share	$0.15	$0.30
Unvested restricted stock outstanding	313,337		346,946
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock outstanding	103,337	414,483

MackCali_Realty_Corporation_St7

Mack-Cali Realty Corporation Stockholders' Equity (Schedule Of Stock Option Plans) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]
Shares Under Options - Outstanding, beginning balance	10,000
Shares Under Options - Outstanding, ending balance	10,000
Shares Under Options - Options exercisable	5,000
Shares Under Options - Available for grant	4,420,227
Weighted Average Exercise Price - Outstanding, beginning balance	$33.36
Weighted Average Exercise Price - Outstanding, ending balance	$33.36
Outstanding stock option price range, lower range	$21.25
Outstanding stock option price range, upper range	$45.47

MackCali_Realty_Corporation_St8

Mack-Cali Realty Corporation Stockholders' Equity (Schedule Of Restricted Stock Awards) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015
	item
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Outstanding, Beginning balance	346,946
Shares, Granted	3,786
Shares, Vested	-37,392
Shares, Forfeited	-3
Shares, Outstanding, Ending balance	313,337
Weighted-Average Grant-Date Fair Value, Outstanding beginning balance	$21.09
Weighted-Average Grant-Date Fair Value, Granted	$19.53
Weighted-Average Grant-Date Fair Value, Vested	$21.59
Weighted-Average Grant-Date Fair Value, Forfeited	$26.36
Weighted-Average Grant-Date Fair Value, Outstanding ending balance	$21.01
Number of executive officers who departed	2

MackCali_Realty_Corporation_St9

Mack-Cali Realty Corporation Stockholders' Equity (Earnings Per Share Tables - Basic Computation Of EPS) (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]
Net loss	($3,325)	($17,628)
Add: Noncontrolling interest in consolidated joint ventures	490	322
Add (deduct): Noncontrolling interest in Operating Partnership	314	2,008
Net loss available to common shareholders	($2,521)	($15,298)
Weighted average common shares	89,192	88,289
Net loss available to common shareholders	($0.03)	($0.17)

Recovered_Sheet2

Mack-Cali Realty Corporation Stockholders' Equity (Earnings Per Share Tables - Diluted Computation Of EPS) (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]
Net loss available to common shareholders	($2,521)	($15,298)
Add (deduct): Noncontrolling interest in Operating Partnership	-314	-2,008
Net loss for diluted earnings per share	($2,835)	($17,306)
Weighted average common shares	100,266	99,876
Net loss available to common unitholders	($0.03)	($0.17)

Recovered_Sheet3

Mack-Cali Realty Corporation Stockholders' Equity (Schedule Of Reconciliation Of Shares Used In Basic EPS Calculation To Shares Used In Diluted EPS Calculation) (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]
Basic EPS shares	89,192	88,289
Add: Operating Partnership - common units	11,074	11,587
Diluted EPS Shares	100,266	99,876

Noncontrolling_Interests_In_Su2

Noncontrolling Interests In Subsidiaries (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Noncontrolling Interest [Line Items]
Number of common shares received upon redemption of common units	1
Rebalance of ownership percentage	$45,000
Percentage of noncontrolling interest	11.00%	11.10%
Participation Rights [Member]
Noncontrolling Interest [Line Items]
Number of properties	3
Excess net cash flow remaining after the distribution to the Company	50.00%
Internal rate of return	10.00%
Future Developments [Member] | Participation Rights [Member]
Noncontrolling Interest [Line Items]
Number of properties	1

Noncontrolling_Interests_In_Su3

Noncontrolling Interests In Subsidiaries (Changes In Noncontrolling Interests Of Subsidiaries) (Details)	3 Months Ended
	Mar. 31, 2015	Mar. 10, 2015	Dec. 09, 2014
Noncontrolling Interests In Subsidiaries [Abstract]
Balance, Beginning	11,083,876	11,036,898	11,083,876
Redemption of common units for shares of common stock	-46,978
Balance, Ending	11,036,898	11,036,898	11,083,876

Noncontrolling_Interests_In_Su4

Noncontrolling Interests In Subsidiaries (Schedule Of Activity Of Noncontrolling Interests) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Noncontrolling Interest [Line Items]
Balance, value	$1,882,011
Net loss	-3,325	-17,628
Common unit distributions	-1,656
Increase in noncontrolling interest in consolidated joint ventures	94
Balance, value	1,864,223
Noncontrolling Interests In Subsidiaries [Member]
Noncontrolling Interest [Line Items]
Balance, value	257,230	276,096
Net loss	-804	-2,330
Common unit distributions	-1,656	-3,455
Increase in noncontrolling interest in consolidated joint ventures	94
Redemption of common units for common stock	-857	-6,452
Rebalancing of ownership percentage between parent and subsidiaries	45	-21
Balance, value	$254,052	$263,838

Segment_Reporting_Narrative_De

Segment Reporting (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Number of business segments	3
Foreign Locations [Member]
Segment Reporting Information [Line Items]
Revenue	$0	$0
Long lived assets	$0		$0

Segment_Reporting_Selected_Res

Segment Reporting (Selected Results Of Operations And Asset Information) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
Segment Reporting Information [Line Items]
Total revenues	$153,715,000		$169,596,000
Total operating and interest expenses	112,853,000	[1]	141,004,000	[1]
Equity in earnings (loss) of unconsolidated joint ventures	-3,529,000		-1,235,000
Net operating income (loss)	37,333,000	[2]	27,357,000	[2]
Total assets	4,198,854,000				4,192,247,000
Total long-lived assets	3,664,450,000	[3]			3,670,704,000	[3]
Investments in unconsolidated joint ventures	262,052,000				247,468,000
Real Estate - Commercial And Other [Member]
Segment Reporting Information [Line Items]
Total revenues	139,759,000		157,520,000
Total operating and interest expenses	72,198,000	[1]	86,933,000	[1]
Equity in earnings (loss) of unconsolidated joint ventures	-1,368,000		988,000
Net operating income (loss)	66,193,000	[2]	71,575,000	[2]
Total assets	3,627,443,000				3,636,126,000
Total long-lived assets	3,336,340,000	[3]			3,344,840,000	[3]
Investments in unconsolidated joint ventures	79,094,000				81,649,000
Real Estate - Multi Family [Member]
Segment Reporting Information [Line Items]
Total revenues	6,584,000		5,801,000
Total operating and interest expenses	3,321,000	[1]	2,701,000	[1]
Equity in earnings (loss) of unconsolidated joint ventures	-2,161,000		-2,223,000
Net operating income (loss)	1,102,000	[2]	877,000	[2]
Total assets	515,643,000				492,362,000
Total long-lived assets	321,295,000	[3]			318,524,000	[3]
Investments in unconsolidated joint ventures	182,554,000				164,912,000
Multi Family Services [Member]
Segment Reporting Information [Line Items]
Total revenues	8,232,000	[4]	6,948,000	[5]
Total operating and interest expenses	9,655,000	[1]	10,159,000	[1]
Net operating income (loss)	-1,423,000	[2]	-3,211,000	[2]
Total assets	11,154,000				11,158,000
Total long-lived assets	3,811,000	[3]			3,858,000	[3]
Investments in unconsolidated joint ventures	404,000				907,000
Fee revenue	1,300,000		800,000
Corporate & Other [Member]
Segment Reporting Information [Line Items]
Total revenues	-860,000	[6]	-673,000	[6]
Total operating and interest expenses	27,679,000	[1],[6]	41,211,000	[1],[6]
Net operating income (loss)	-28,539,000	[2],[6]	-41,884,000	[2],[6]
Total assets	44,614,000	[6]			52,601,000	[6]
Total long-lived assets	$3,004,000	[3],[6]			$3,482,000	[3],[6]
[1]	Total operating and interest expenses represent the sum of: real estate taxes; utilities; operating services; direct construction costs; real estate services expenses; general and administrative and interest expense (net of interest income). All interest expense, net of interest and other investment income, (including for property-level mortgages) is excluded from segment amounts and classified in Corporate & Other for all periods.
[2]	Net operating income represents total revenues less total operating and interest expenses (as defined in Note bab), plus equity in earnings (loss) of unconsolidated joint ventures, for the period.
[3]	Long-lived assets are comprised of net investment in rental property, unbilled rents receivable and goodwill.
[4]	Includes $1.3 million of fees earned for this period from the multi-family real estate segment, which are eliminated in consolidation.
[5]	Includes $0.8 million of fees earned for this period from the multi-family real estate segment, which are eliminated in consolidation.
[6]	Corporate & Other represents all corporate-level items (including interest and other investment income, interest expense, non-property general and administrative expense, construction services revenue and direct construction costs) as well as intercompany eliminations necessary to reconcile to consolidated Company totals.

Segment_Reporting_Schedule_Of_

Segment Reporting (Schedule Of Reconciliation Of Net Operating Income To Income From Continuing Operations) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Segment Reporting [Abstract]
Net operating income	$37,333	[1]	$27,357	[1]
Depreciation and amortization	-40,802		-44,985
Realized gains (losses) on disposition of rental property, net	144
Net loss	-3,325		-17,628
Noncontrolling interest in consolidated joint ventures	490		322
Noncontrolling interest in Operating Partnership	314		2,008
Net loss available to common shareholders	($2,521)		($15,298)
[1]	Net operating income represents total revenues less total operating and interest expenses (as defined in Note bab), plus equity in earnings (loss) of unconsolidated joint ventures, for the period.