Mack Cali Realty L P 10-K 20 Feb 19 2018 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 15, 2019	Jun. 30, 2018
Entity Registrant Name	MACK CALI REALTY CORP
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Entity Central Index Key	924,901
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Public Float			$ 1,817,581,899
Entity Common Stock, Shares Outstanding		90,320,744
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Mack-Cali Realty LP [Member]
Entity Registrant Name	MACK CALI REALTY LP
Entity Central Index Key	1,067,063
Entity Filer Category	Large Accelerated Filer

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Rental property
Land and leasehold interests	$ 807,236	$ 786,789
Buildings and improvements	4,109,797	3,955,122
Tenant improvements	335,266	330,686
Furniture, fixtures and equipment	53,718	30,247
Gross investment in rental property	5,306,017	5,102,844
Less - accumulated depreciation and amortization	(1,097,868)	(1,087,083)
Total investment in rental property	4,208,149	4,015,761
Rental property held for sale, net	108,848	171,578
Net investment in rental property	4,316,997	4,187,339
Cash and cash equivalents	29,633	28,180
Restricted cash	19,921	39,792
Investments in unconsolidated joint ventures	232,750	252,626
Unbilled rents receivable, net	100,737	100,842
Deferred charges, goodwill and other assets, net	355,234	342,320
Accounts receivable, net of allowance for doubtful accounts of $1,108 and $1,138	5,372	6,786
Total assets	5,060,644	4,957,885
LIABILITIES AND EQUITY
Senior unsecured notes, net	570,314	569,145
Unsecured revolving credit facility and term loans	790,939	822,288
Mortgages, loans payable and other obligations, net	1,431,398	1,418,135
Dividends and distributions payable	21,877	21,158
Accounts payable, accrued expenses and other liabilities	168,115	192,716
Rents received in advance and security deposits	41,244	43,993
Accrued interest payable	9,117	9,519
Total liabilities	3,033,004	3,076,954
Commitments and contingencies
Redeemable noncontrolling interests	330,459	212,208
Mack-Cali Realty Corporation stockholders' equity:
Common stock, $0.01 par value, 190,000,000 shares authorized, 90,320,306 and 89,914,113 shares outstanding	903	899
Additional paid-in capital	2,561,503	2,565,136
Dividends in excess of net earnings	(1,084,518)	(1,096,429)
Accumulated other comprehensive income	8,770	6,689
Total Mack-Cali Realty Corporation stockholders' equity	1,486,658	1,476,295
Noncontrolling interests in subsidiaries:
Operating Partnership	168,373	171,395
Consolidated joint ventures	42,150	21,033
Total noncontrolling interests in subsidiaries	210,523	192,428
Total equity	1,697,181	1,668,723
Total liabilities and equity	5,060,644	4,957,885
Mack-Cali Realty LP [Member]
Rental property
Land and leasehold interests	807,236	786,789
Buildings and improvements	4,109,797	3,955,122
Tenant improvements	335,266	330,686
Furniture, fixtures and equipment	53,718	30,247
Gross investment in rental property	5,306,017	5,102,844
Less - accumulated depreciation and amortization	(1,097,868)	(1,087,083)
Total investment in rental property	4,208,149	4,015,761
Rental property held for sale, net	108,848	171,578
Net investment in rental property	4,316,997	4,187,339
Cash and cash equivalents	29,633	28,180
Restricted cash	19,921	39,792
Investments in unconsolidated joint ventures	232,750	252,626
Unbilled rents receivable, net	100,737	100,842
Deferred charges, goodwill and other assets, net	355,234	342,320
Accounts receivable, net of allowance for doubtful accounts of $1,108 and $1,138	5,372	6,786
Total assets	5,060,644	4,957,885
LIABILITIES AND EQUITY
Senior unsecured notes, net	570,314	569,145
Unsecured revolving credit facility and term loans	790,939	822,288
Mortgages, loans payable and other obligations, net	1,431,398	1,418,135
Dividends and distributions payable	21,877	21,158
Accounts payable, accrued expenses and other liabilities	168,115	192,716
Rents received in advance and security deposits	41,244	43,993
Accrued interest payable	9,117	9,519
Total liabilities	3,033,004	3,076,954
Commitments and contingencies
Redeemable noncontrolling interests	330,459	212,208
Mack-Cali Realty Corporation stockholders' equity:
General Partner, 90,320,306 and 89,914,113 common units outstanding	1,413,497	1,407,366
Limited partners, 10,174,285 and 10,438,855 common units outstanding	232,764	233,635
Accumulated other comprehensive income	8,770	6,689
Total Mack-Cali Realty, L.P. partners' capital	1,655,031	1,647,690
Noncontrolling interests in subsidiaries:
Noncontrolling interests in consolidated joint ventures	42,150	21,033
Total equity	1,697,181	1,668,723
Total liabilities and equity	$ 5,060,644	$ 4,957,885

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts receivable	$ 1,108	$ 1,138
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	190,000,000	190,000,000
Common stock, shares outstanding	90,320,306	89,914,113
Mack-Cali Realty LP [Member]
Allowance for doubtful accounts receivable	$ 1,108	$ 1,138
General partner common units outstanding	90,320,306	89,914,113
Limited partners common units outstanding	10,174,285	10,438,855

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
REVENUES
Total revenues	$ 132,936	$ 132,114	$ 126,589	$ 138,967	$ 143,529	$ 160,018	$ 162,766	$ 149,887	$ 530,606	$ 616,200	$ 613,398
EXPENSES
Real estate taxes									64,555	81,364	87,379
Utilities									39,054	42,598	49,624
Operating services									102,626	107,379	103,954
Real estate services expenses									17,919	23,394	26,260
General and administrative									53,988	50,949	51,979
Acquisition-related costs											2,880
Depreciation and amortization									174,847	205,169	186,684
Land impairments									24,566
Total expenses									477,555	510,853	508,760
OTHER (EXPENSE) INCOME
Interest expense									(83,754)	(93,388)	(94,889)
Interest and other investment income (loss)									3,389	2,766	1,614
Equity in earnings (loss) of unconsolidated joint ventures									(127)	(6,081)	18,788
Gain on change of control of interests									14,217		15,347
Realized gains (losses) and unrealized losses on disposition of rental property, net									99,436	2,364	109,666
Gain on disposition of developable land									30,939
Gain on sale of investment in unconsolidated joint venture										23,131	5,670
Loss from extinguishment of debt, net									(10,750)	(421)	(30,540)
Total other income (expense)									53,350	(71,629)	25,656
Net income	52,523	1,689	1,501	50,688	5,411	44,703	(39,125)	22,729	106,401	33,718	130,294
Noncontrolling interest in consolidated joint ventures									1,216	1,018	651
Noncontrolling interest in Operating Partnership									(9,527)	(2,711)	(13,721)
Redeemable noncontrolling interest									(13,979)	(8,840)
Net income available to common shareholders	$ 43,804	$ (1,478)	$ (1,251)	$ 43,036	$ 2,582	$ 38,054	$ (37,330)	$ 19,879	$ 84,111	$ 23,185	$ 117,224
Basic earnings per common share:
Net income available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.31
Diluted earnings per common share:
Net income available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.30
Basic weighted average shares outstanding									90,388	90,005	89,746
Diluted weighted average shares outstanding									100,724	100,703	100,498
Base Rents [Member]
REVENUES
Total revenues									$ 436,222	$ 501,334	$ 506,877
Escalations And Recoveries From Tenants [Member]
REVENUES
Total revenues									44,121	58,767	60,505
Real Estate Services [Member]
REVENUES
Total revenues									17,094	23,129	26,589
Parking Income [Member]
REVENUES
Total revenues									22,117	20,270	13,630
Other Income [Member]
REVENUES
Total revenues									11,052	12,700	5,797
Mack-Cali Realty LP [Member]
REVENUES
Total revenues	$ 132,936	$ 132,114	$ 126,589	$ 138,967	$ 143,529	$ 160,018	$ 162,766	$ 149,887	530,606	616,200	613,398
EXPENSES
Real estate taxes									64,555	81,364	87,379
Utilities									39,054	42,598	49,624
Operating services									102,626	107,379	103,954
Real estate services expenses									17,919	23,394	26,260
General and administrative									53,988	50,949	51,979
Acquisition-related costs											2,880
Depreciation and amortization									174,847	205,169	186,684
Land impairments									24,566
Total expenses									477,555	510,853	508,760
OTHER (EXPENSE) INCOME
Interest expense									(83,754)	(93,388)	(94,889)
Interest and other investment income (loss)									3,389	2,766	1,614
Equity in earnings (loss) of unconsolidated joint ventures									(127)	(6,081)	18,788
Gain on change of control of interests									14,217		15,347
Realized gains (losses) and unrealized losses on disposition of rental property, net									99,436	2,364	109,666
Gain on disposition of developable land									30,939
Gain on sale of investment in unconsolidated joint venture										23,131	5,670
Loss from extinguishment of debt, net									(10,750)	(421)	(30,540)
Total other income (expense)									53,350	(71,629)	25,656
Net income	52,523	1,689	1,501	50,688	5,411	44,703	(39,125)	22,729	106,401	33,718	130,294
Noncontrolling interest in consolidated joint ventures									1,216	1,018	651
Redeemable noncontrolling interest									(13,979)	(8,840)
Net income available to common shareholders	$ 48,757	$ (1,645)	$ (1,393)	$ 47,919	$ 2,881	$ 42,467	$ (41,626)	$ 22,174	$ 93,638	$ 25,896	$ 130,945
Basic earnings per common share:
Net income available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.31
Diluted earnings per common share:
Net income available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.30
Basic weighted average units outstanding									100,634	100,410	100,245
Diluted weighted average units outstanding									100,724	100,703	100,498
Mack-Cali Realty LP [Member] | Base Rents [Member]
REVENUES
Total revenues									$ 436,222	$ 501,334	$ 506,877
Mack-Cali Realty LP [Member] | Escalations And Recoveries From Tenants [Member]
REVENUES
Total revenues									44,121	58,767	60,505
Mack-Cali Realty LP [Member] | Real Estate Services [Member]
REVENUES
Total revenues									17,094	23,129	26,589
Mack-Cali Realty LP [Member] | Parking Income [Member]
REVENUES
Total revenues									22,117	20,270	13,630
Mack-Cali Realty LP [Member] | Other Income [Member]
REVENUES
Total revenues									$ 11,052	$ 12,700	$ 5,797

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net income	$ 106,401	$ 33,718	$ 130,294
Other comprehensive income:
Net unrealized gain on derivative instruments for interest rate swaps	2,318	5,250	2,216
Comprehensive income	108,719	38,968	132,510
Comprehensive (income) loss attributable to noncontrolling interest in consolidated joint ventures	1,216	1,018	651
Comprehensive (income) loss attributable to redeemable noncontrolling interest	(13,979)	(8,840)
Comprehensive (income) loss attributable to noncontrolling interest in Operating Partnership	(9,764)	(3,257)	(13,952)
Comprehensive income attributable to common shareholders	86,192	27,889	119,209
Mack-Cali Realty LP [Member]
Net income	106,401	33,718	130,294
Other comprehensive income:
Net unrealized gain on derivative instruments for interest rate swaps	2,318	5,250	2,216
Comprehensive income	108,719	38,968	132,510
Comprehensive (income) loss attributable to noncontrolling interest in consolidated joint ventures	1,216	1,018	651
Comprehensive (income) loss attributable to redeemable noncontrolling interest	(13,979)	(8,840)
Comprehensive income attributable to common shareholders	$ 95,956	$ 31,146	$ 133,161

Consolidated Statement Of Chang

Consolidated Statement Of Changes In Equity - USD ($) shares in Thousands, $ in Thousands	Mack-Cali Realty LP [Member]General Partner Common Units [Member]	Mack-Cali Realty LP [Member]Limited Partner Common Units [Member]	Mack-Cali Realty LP [Member]General Partner Common Unitholders [Member]	Mack-Cali Realty LP [Member]Limited Partner Common Unitholders [Member]	Mack-Cali Realty LP [Member]Noncontrolling Interest In Consolidated Joint Ventures [Member]	Mack-Cali Realty LP [Member]Accumulated Other Comprehensive Income (Loss) [Member]	Mack-Cali Realty LP [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Dividends In Excess Of Net Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests In Subsidiaries [Member]	Total
Balance, value at Dec. 31, 2015								$ 896	$ 2,570,392	$ (1,115,612)		$ 228,032	$ 1,683,708
Balance, shares at Dec. 31, 2015								89,584
Balance, value at Dec. 31, 2015			$ 1,399,419	$ 227,148	$ 57,141		$ 1,683,708
Balance, units at Dec. 31, 2015	89,584	10,517
Net income			117,224	13,721	(651)		130,294			117,224		13,070	130,294
Common stock dividends										(53,796)			(53,796)
Common unit distributions			(53,796)	(6,619)			(60,415)					(6,619)	(6,619)
Decrease in noncontrolling interest in consolidated joint ventures			414		(35,544)		(35,130)		414			(35,544)	(35,130)
Redemption of common units for common stock, value			(474)	474					(474)			474
Redemption of common units for common stock, shares	29	(29)						29
Shares issued under Dividend Reinvestment and Stock Purchase Plan, value			71				71		71				71
Shares issued under Dividend Reinvestment and Stock Purchase Plan, shares	3							3
Directors' deferred compensation plan, value			372				372		372				372
Stock compensation, value			3,466	2,180			5,646	$ 1	3,465			2,180	5,646
Stock compensation, shares	85							85
Cancellation of restricted shares, value			(75)				(75)		(75)				(75)
Cancellation of restricted shares, shares	(4)							(4)
Other comprehensive income				231		$ 1,985	2,216				$ 1,985	231	2,216
Rebalancing of ownership percentage between parent and subsidiaries									1,360			(1,360)
Balance, value at Dec. 31, 2016								$ 897	2,576,473	(1,052,184)	1,985	199,516	1,726,687
Balance, shares at Dec. 31, 2016								89,697
Balance, value at Dec. 31, 2016			1,467,569	236,187	20,946	1,985	1,726,687
Balance, units at Dec. 31, 2016	89,697	10,488
Net income			23,185	2,711	7,822		33,718			23,185		10,533	33,718
Common stock dividends										(67,430)			(67,430)
Common unit distributions			(67,430)	(8,629)			(76,059)					(8,629)	(8,629)
Issuance of limited partner common units, value		$ 99		2,793			2,793					2,793	2,793
Redeemable noncontrolling interest			(17,951)	(2,074)	(8,840)		(28,865)		(17,951)			(10,914)	(28,865)
Decrease in noncontrolling interest in consolidated joint ventures			(3,756)		1,105		(2,651)		(3,756)			1,105	(2,651)
Redemption of common units for common stock, value			(2,531)	2,531				$ (1)	(2,530)			2,531
Redemption of common units for common stock, shares	149	(149)						149
Shares issued under Dividend Reinvestment and Stock Purchase Plan, value			67				67		67				67
Shares issued under Dividend Reinvestment and Stock Purchase Plan, shares	2							2
Directors' deferred compensation plan, value			482				482		482				482
Stock compensation, value			2,815	4,632			7,447	$ 1	2,814			4,632	7,447
Stock compensation, shares	70							70
Cancellation of restricted shares, value			(146)				(146)		(146)				(146)
Cancellation of restricted shares, shares	(4)							(4)
Other comprehensive income				546		4,704	5,250				4,704	546	5,250
Rebalancing of ownership percentage between parent and subsidiaries									4,623			(4,623)
Balance, value at Dec. 31, 2017								$ 899	2,565,136	(1,096,429)	6,689	192,428	1,668,723
Balance, shares at Dec. 31, 2017								89,914
Balance, value at Dec. 31, 2017			1,407,366	233,635	21,033	6,689	1,668,723
Balance, units at Dec. 31, 2017	89,914	10,438
Net income			84,111	9,527	12,763		106,401			84,111		22,290	106,401
Common stock dividends										(72,200)			(72,200)
Common unit distributions			(72,200)	(9,022)			(81,222)					(9,022)	(9,022)
Redeemable noncontrolling interest			(11,425)	(1,296)	(13,979)		(26,700)		(11,425)			(15,275)	(26,700)
Decrease in noncontrolling interest in consolidated joint ventures					22,333		22,333					22,333	22,333
Redemption of common units for common stock, value			(4,344)	4,344				$ (3)	(4,341)			4,344
Redemption of common units for common stock, shares	264	(264)						264
Shares issued under Dividend Reinvestment and Stock Purchase Plan, value			(37)				(37)		(37)				(37)
Shares issued under Dividend Reinvestment and Stock Purchase Plan, shares	4							4
Directors' deferred compensation plan, value			507				507		507				507
Stock compensation, value			1,414	5,480			6,894	$ 1	1,413			5,480	6,894
Stock compensation, shares	147							147
Cancellation of restricted shares, value			(583)	(1,453)			(2,036)		(583)			(1,453)	(2,036)
Cancellation of restricted shares, shares	(9)							(9)
Other comprehensive income				237		2,081	2,318				2,081	237	2,318
Rebalancing of ownership percentage between parent and subsidiaries									2,151			(2,151)
Balance, value at Dec. 31, 2018								$ 903	$ 2,561,503	$ (1,084,518)	$ 8,770	$ 210,523	$ 1,697,181
Balance, shares at Dec. 31, 2018								90,320
Balance, value at Dec. 31, 2018			$ 1,413,497	$ 232,764	$ 42,150	$ 8,770	$ 1,697,181
Balance, units at Dec. 31, 2018	90,320	10,174

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income		$ 106,401		$ 33,718		$ 130,294
Adjustments to reconcile net income to net cash provided by Operating activities:
Depreciation and amortization, including related intangible assets and liabilities		170,284		198,674		186,549
Amortization of directors deferred compensation stock units		507		482		372
Amortization of stock compensation		6,894		7,447		5,646
Amortization of deferred financing costs		5,028		4,612		4,582
Amortization of debt discount and mark-to-market		(948)		(287)		1,686
Equity in (earnings) loss of unconsolidated joint ventures		127		6,081		(18,788)
Distributions of cumulative earnings from unconsolidated joint ventures		9,182		8,186		6,120
Gain on change of control of interests		(14,217)				(15,347)
Realized (gains) losses and unrealized losses on disposition of rental property, net		(99,436)		(2,364)		(109,666)
Gain on disposition of developable land		(30,939)
Gain on sale of investments in unconsolidated joint ventures				(23,131)		(5,670)
Loss (gain) from extinguishment of debt		10,750		421		(12,420)
Land impairments		24,566
Changes in operating assets and liabilities:
Increase in unbilled rents receivable, net		(7,519)		(11,286)		(12,775)
Increase in deferred charges, goodwill and other assets		(29,377)		(19,710)		(33,878)
Decrease in accounts receivable, net		1,382		2,831		596
Increase (decrease) in accounts payable, accrued expenses and other liabilities		13,915		(9,012)		(14,535)
Increase (decrease) in rents received in advance and security deposits		875		(1,817)		(3,297)
(Decrease) increase in accrued interest payable		(402)		1,296		(9,362)
Net cash provided by operating activities		167,073		196,141		100,107
CASH FLOWS FROM INVESTING ACTIVITIES
Rental property acquisitions and related intangibles		(164,838)		(619,350)		(407,869)
Rental property additions and improvements		(168,398)		(90,068)		(121,582)
Development of rental property and other related costs		(184,799)		(267,845)		(206,955)
Proceeds from the sales of rental property		338,015		312,596		604,978
Proceeds from the sale of investments in unconsolidated joint ventures				98,599		6,420
Investments in notes receivable				(47,049)
Repayment of notes receivable		12,102		74,945		500
Investment in unconsolidated joint ventures		(11,789)		(36,060)		(35,930)
Distributions in excess of cumulative earnings from unconsolidated joint ventures		11,553		5,877		22,231
Proceeds from investment receivable				3,625
Net cash used in investing activities		(168,154)		(564,730)		(138,207)
CASH FLOW FROM FINANCING ACTIVITIES
Borrowings from revolving credit facility		461,000		730,000		1,165,000
Repayment of revolving credit facility		(494,000)		(866,000)		(1,034,000)
Repayment of senior unsecured notes				(250,000)		(448,339)
Borrowings from unsecured term loan				325,000		350,000
Proceeds from mortgages and loans payable		434,293		518,852		474,344
Repayment of mortgages, loans payable and other obligations		(418,495)		(156,760)		(349,426)
Acquisition of noncontrolling interests				(2,021)		(37,946)
Issuance of redeemable noncontrolling interests, net		105,000		139,002
Payment of financing costs		(3,576)		(9,230)		(9,414)
Contributions from (to) noncontrolling interests, net		(7,542)		(19)		1,065
Payment of dividends and distributions		(94,017)		(77,826)		(60,041)
Net cash (used in) provided by financing activities		(17,337)		350,998		51,243
Net (decrease) increase in cash and cash equivalents		(18,418)		(17,591)		13,143
Cash, cash equivalents and restricted cash, beginning of period	[2]	67,972	[1]	85,563	[1]	72,420
Cash, cash equivalents and restricted cash, end of period	[1]	49,554		67,972	[2]	85,563	[2]
Mack-Cali Realty LP [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income		106,401		33,718		130,294
Adjustments to reconcile net income to net cash provided by Operating activities:
Depreciation and amortization, including related intangible assets and liabilities		170,284		198,674		186,549
Amortization of directors deferred compensation stock units		507		482		372
Amortization of stock compensation		6,894		7,447		5,646
Amortization of deferred financing costs		5,028		4,612		4,582
Amortization of debt discount and mark-to-market		(948)		(287)		1,686
Equity in (earnings) loss of unconsolidated joint ventures		127		6,081		(18,788)
Distributions of cumulative earnings from unconsolidated joint ventures		9,182		8,186		6,120
Gain on change of control of interests		(14,217)				(15,347)
Realized (gains) losses and unrealized losses on disposition of rental property, net		(99,436)		(2,364)		(109,666)
Gain on disposition of developable land		(30,939)
Gain on sale of investments in unconsolidated joint ventures				(23,131)		(5,670)
Loss (gain) from extinguishment of debt		10,750		421		(12,420)
Land impairments		24,566
Changes in operating assets and liabilities:
Increase in unbilled rents receivable, net		(7,519)		(11,286)		(12,775)
Increase in deferred charges, goodwill and other assets		(29,377)		(19,710)		(33,878)
Decrease in accounts receivable, net		1,382		2,831		596
Increase (decrease) in accounts payable, accrued expenses and other liabilities		13,915		(9,012)		(14,535)
Increase (decrease) in rents received in advance and security deposits		875		(1,817)		(3,297)
(Decrease) increase in accrued interest payable		(402)		1,296		(9,362)
Net cash provided by operating activities		167,073		196,141		100,107
CASH FLOWS FROM INVESTING ACTIVITIES
Rental property acquisitions and related intangibles		(164,838)		(619,350)		(407,869)
Rental property additions and improvements		(168,398)		(90,068)		(121,582)
Development of rental property and other related costs		(184,799)		(267,845)		(206,955)
Proceeds from the sales of rental property		338,015		312,596		604,978
Proceeds from the sale of investments in unconsolidated joint ventures				98,599		6,420
Investments in notes receivable				(47,049)
Repayment of notes receivable		12,102		74,945		500
Investment in unconsolidated joint ventures		(11,789)		(36,060)		(35,930)
Distributions in excess of cumulative earnings from unconsolidated joint ventures		11,553		5,877		22,231
Proceeds from investment receivable				3,625
Net cash used in investing activities		(168,154)		(564,730)		(138,207)
CASH FLOW FROM FINANCING ACTIVITIES
Borrowings from revolving credit facility		461,000		730,000		1,165,000
Repayment of revolving credit facility		(494,000)		(866,000)		(1,034,000)
Repayment of senior unsecured notes				(250,000)		(448,339)
Borrowings from unsecured term loan				325,000		350,000
Proceeds from mortgages and loans payable		434,293		518,852		474,344
Repayment of mortgages, loans payable and other obligations		(418,495)		(156,760)		(349,426)
Acquisition of noncontrolling interests				(2,021)		(37,946)
Issuance of redeemable noncontrolling interests, net		105,000		139,002
Payment of financing costs		(3,576)		(9,230)		(9,414)
Contributions from (to) noncontrolling interests, net		(7,542)		(19)		1,065
Payment of dividends and distributions		(94,017)		(77,826)		(60,041)
Net cash (used in) provided by financing activities		(17,337)		350,998		51,243
Net (decrease) increase in cash and cash equivalents		(18,418)		(17,591)		13,143
Cash, cash equivalents and restricted cash, beginning of period	[2]	67,972	[1]	85,563	[1]	72,420
Cash, cash equivalents and restricted cash, end of period	[1]	$ 49,554		$ 67,972	[2]	$ 85,563	[2]
[1]	Includes Restricted Cash of $19,921, $39,792 and $53,952 as of December 31, 2018, 2017 and 2016, respectively, pursuant to the adoption of ASU 2016-15.
[2]	Includes Restricted Cash of $39,792, $53,952 and $35,343 as of December 31, 2017, 2016 and 2015, respectively, pursuant to the adoption of ASU 2016-15.

Consolidated Statements Of Ca_2

Consolidated Statements Of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted cash	$ 19,921	$ 39,792	$ 53,952	$ 35,343
Mack-Cali Realty LP [Member]
Restricted cash	$ 19,921	$ 39,792	$ 53,952	$ 35,343

Organization And Basis Of Prese

Organization And Basis Of Presentation	12 Months Ended
	Dec. 31, 2018
Organization And Basis Of Presentation [Line Items]
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 “General Partner”), is a fully-integrated, self-administered, self-managed real estate investment trust (“REIT”). The General Partner controls Mack-Cali Realty, L.P., a Delaware limited partnership, together with its subsidiaries (collectively, the “Operating Partnership”), as its sole general partner and owned an 89.8 percent and 89.6 percent common unit interest in the Operating Partnership as of December 31, 2018 and December 31, 2017 , respectively. The General Partner’s business is the ownership of interests in and operation of the Operating Partnership and all of the General Partner’s expenses are incurred for the benefit of the Operating Partnership. The General Partner is reimbursed by the Operating Partnership for all expenses it incurs relating to the ownership and operation of the Operating Partnership.  The Operating Partnership conducts the business of providing leasing, management, acquisition, development, and tenant-related services for its General Partner. The Operating Partnership, through its operating divisions and subsidiaries, including the Mack-Cali property-owning partnerships and limited liability companies, is the entity through which all of the General Partner’s operations are conducted. Unless stated otherwise or the context requires, the “Company” refers to the General Partner and its subsidiaries, including the Operating Partnership and its subsidiaries.  As of December 31, 2018 , the Company owned or had interests in 135 properties, consisting of 56 office and 55 flex properties, totaling approximately 15.4 million square feet, leased to approximately 700 commercial tenants, and 24 multi-family rental properties containing 6,910 apartment units, plus developable land (collectively, the “Properties”). The Properties are comprised of 56 office buildings totaling approximately 12.6 million square feet (which include four buildings aggregating approximately 0.5 million square feet owned by unconsolidated joint ventures in which the Company has investment interests), 47 office/flex buildings totaling approximately 2.7 million square feet, 24 multi-family properties totaling 6,910 apartment units (which include eight properties aggregating 2,922 apartment units owned by unconsolidated joint ventures in which the Company has investment interests), six parking/retail properties totaling approximately 137,100 square feet (which include two buildings aggregating 81,700 square feet owned by unconsolidated joint ventures in which the Company has investment interests), a hotel (which is owned by an unconsolidated joint venture in which the Company has an investment interest) and a parcel of land leased to others. The Properties are located in six 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 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 (i) the ability to make decisions about the entity's activities through voting or similar rights, (ii) the obligation to absorb the expected losses of the entity, or (iii) the right to receive the expected residual returns of the entity; (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 substantially all of 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.  On January 1, 2016, the Company adopted accounting guidance under ASC 810, Consolidation, modifying the analysis it must perform to determine whether it should consolidate certain types of legal entities. The guidance does not amend the existing disclosure requirements for variable interest entities or voting interest model entities. The guidance, however, modified the requirements to qualify under the voting interest model. Under the revised guidance, the Operating Partnership will be a variable interest entity of the parent company, Mack-Cali Realty Corporation. As the Operating Partnership is already consolidated in the balance sheets of Mack-Cali Realty Corporation, the identification of this entity as a variable interest entity has no impact on the consolidated financial statements of Mack-Cali Realty Corporation. There were no other legal entities qualifying under the scope of the revised guidance that were consolidated as a result of the adoption.  As of December 31, 2018 and 2017 , the Company’s investments in consolidated real estate joint ventures, which are variable interest entities in which the Company is deemed to be the primary beneficiary, other than Roseland Residential, L.P. (See Note 3: Rockpoint Transaction), have total real estate assets of $480.4 million and $215.5 million, respectively, mortgages of $241.5 million and $81.2 million, respectively, and other liabilities of $23 million and $19.3 million, respectively.  The financial statements have been prepared in conformity with GAAP. 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. These estimates and assumptions are based on management’s historical experience that are believed to be reasonable at the time. However, because future events and their effects cannot be determined with certainty, the determination of estimates requires the exercise of judgment. Actual results could differ from those estimates. Certain reclassifications have been made to prior period amounts in order to conform with current period presentation.
Mack-Cali Realty LP [Member]
Organization And Basis Of Presentation [Line Items]
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 “General Partner”), is a fully-integrated, self-administered, self-managed real estate investment trust (“REIT”). The General Partner controls Mack-Cali Realty, L.P., a Delaware limited partnership, together with its subsidiaries (collectively, the “Operating Partnership”), as its sole general partner and owned an 89.8 percent and 89.6 percent common unit interest in the Operating Partnership as of December 31, 2018 and December 31, 2017 , respectively. The General Partner’s business is the ownership of interests in and operation of the Operating Partnership and all of the General Partner’s expenses are incurred for the benefit of the Operating Partnership. The General Partner is reimbursed by the Operating Partnership for all expenses it incurs relating to the ownership and operation of the Operating Partnership.  The Operating Partnership conducts the business of providing leasing, management, acquisition, development, and tenant-related services for its General Partner. The Operating Partnership, through its operating divisions and subsidiaries, including the Mack-Cali property-owning partnerships and limited liability companies, is the entity through which all of the General Partner’s operations are conducted. Unless stated otherwise or the context requires, the “Company” refers to the General Partner and its subsidiaries, including the Operating Partnership and its subsidiaries.  As of December 31, 2018 , the Company owned or had interests in 135 properties, consisting of 56 office and 55 flex properties, totaling approximately 15.4 million square feet, leased to approximately 700 commercial tenants, and 24 multi-family rental properties containing 6,910 apartment units, plus developable land (collectively, the “Properties”). The Properties are comprised of 56 office buildings totaling approximately 12.6 million square feet (which include four buildings aggregating approximately 0.5 million square feet owned by unconsolidated joint ventures in which the Company has investment interests), 47 office/flex buildings totaling approximately 2.7 million square feet, 24 multi-family properties totaling 6,910 apartment units (which include eight properties aggregating 2,922 apartment units owned by unconsolidated joint ventures in which the Company has investment interests), six parking/retail properties totaling approximately 137,100 square feet (which include two buildings aggregating 81,700 square feet owned by unconsolidated joint ventures in which the Company has investment interests), a hotel (which is owned by an unconsolidated joint venture in which the Company has an investment interest) and a parcel of land leased to others. The Properties are located in six 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 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 (i) the ability to make decisions about the entity's activities through voting or similar rights, (ii) the obligation to absorb the expected losses of the entity, or (iii) the right to receive the expected residual returns of the entity; (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 substantially all of 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.  On January 1, 2016, the Company adopted accounting guidance under ASC 810, Consolidation, modifying the analysis it must perform to determine whether it should consolidate certain types of legal entities. The guidance does not amend the existing disclosure requirements for variable interest entities or voting interest model entities. The guidance, however, modified the requirements to qualify under the voting interest model. Under the revised guidance, the Operating Partnership will be a variable interest entity of the parent company, Mack-Cali Realty Corporation. As the Operating Partnership is already consolidated in the balance sheets of Mack-Cali Realty Corporation, the identification of this entity as a variable interest entity has no impact on the consolidated financial statements of Mack-Cali Realty Corporation. There were no other legal entities qualifying under the scope of the revised guidance that were consolidated as a result of the adoption.  As of December 31, 2018 and 2017 , the Company’s investments in consolidated real estate joint ventures, which are variable interest entities in which the Company is deemed to be the primary beneficiary, other than Roseland Residential, L.P. (See Note 3: Rockpoint Transaction), have total real estate assets of $480.4 million and $215.5 million, respectively, mortgages of $241.5 million and $81.2 million, respectively, and other liabilities of $23 million and $19.3 million, respectively.  The financial statements have been prepared in conformity with GAAP. 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. These estimates and assumptions are based on management’s historical experience that are believed to be reasonable at the time. However, because future events and their effects cannot be determined with certainty, the determination of estimates requires the exercise of judgment. 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 Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Significant Accounting Policies	2. SIGNIFICANT ACCOUNTING POLICIES  Rental Property Rental 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 were expensed as incurred for all real estate acquisitions classified as business combinations, which were substantially all of our operating property acquisitions, through December 31, 2016. The Company early adopted FASB guidance Accounting Standards Update (“ASU”) 2017-01 on January 1, 2017, which revises the definition of a business and is expected to result in more transactions to be accounted for as asset acquisitions and significantly limit transactions that would be accounted for as business combinations. Where an acquisition has been determined to be an asset acquisition, acquisition-related costs are capitalized. 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 $ 2.3 million, $ 2.2 million and $2.6 million for the years ended December 31, 2018 , 2017 and 2016 , 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.  Included in net investment in rental property as of December 31, 2018 and December 31, 2017 is real estate and building and tenant improvements not in service; as follows (dollars in thousands) :     December 31, December 31,  2018 2017  Land held for development (including pre-development costs) (a) $ 465,930 $ 483,432  Development and construction in progress, including land (b) 327,039 535,971  Total $ 792,969 $ 1,019,403  (a) Includes predevelopment and infrastructure costs included in buildings and improvements of $204.9 million and $188.1 million as of December 31, 2018 and December 31, 2017, respectively. (b) Includes land of $49.6 million and $77.0 million as of December 31, 2018 and December 31, 2017, respectively.  The Company considers a construction project as substantially completed and held available for occupancy upon the substantial completion of 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 residents, 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 commercial square footage or multi-family units 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 relative fair values. The Company records goodwill or a gain on bargain purchase (if any) if the net assets acquired/liabilities assumed differ from the purchase consideration of a business 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 or leases.  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, current and historical operating and/or cash flow losses, near-term mortgage debt maturities and/or other factors, including those 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 impairment loss shall be measured as the excess of the carrying value 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 When 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. The Company generally considers assets to be held for sale when the transaction has received appropriate corporate authority, and there are no significant contingencies relating to the sale. If, in management’s opinion, the estimated net sales price, net of selling costs, of the assets which have been identified as held for sale is less than the carrying value of the assets, a valuation allowance (which is recorded as unrealized losses on disposition of rental property) 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 value 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 The 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.  If the venture subsequently makes distributions and the Company does not have an implied or actual commitment to support the operations of the venture, including a general partner interest in the investee, the Company will not record a basis less than zero, rather such amounts will be recorded as equity in earnings of unconsolidated joint ventures. 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 value 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 All highly liquid investments with an original maturity of three months or less when purchased are considered to be cash equivalents. Deferred Financing Costs Costs incurred in obtaining financing are capitalized and amortized over the term of the related indebtedness. Deferred financing costs are presented in the balance sheet as a direct deduction from the carrying value of the debt liability to which they relate, except deferred financing costs related to the revolving credit facility, which are presented in deferred charges, goodwill and other assets. In all cases, amortization of such costs is included in interest expense and was $ 5,028,000 , $ 4,612,000 and $ 4,582,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. If a financing obligation is extinguished early, any unamortized deferred financing costs are written off and included in gains (losses) from extinguishment of debt. Included in loss from extinguishment of debt, net of gains, of $10.8 million, $0.4 million and $ 30.5 million for the years ended December 31, 2018 , 2017 and 2016 were unamortized deferred financing costs which were written off (as non-cash transactions) amounting to $0.6 million, $ 0.4 million and $ 0.7 million, respectively. Deferred Leasing Costs Costs incurred in connection with successfully executed commercial and residential 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, and included in deferred charges, goodwill and other assets, net was approximately $ 3,463,000 , $ 3,146,000 and $ 3,270,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. Upon the adoption of ASC842 on January1, 2019, the Company will no longer capitalize such costs. Goodwill Goodwill 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 value 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 value. If, based on this assessment, management determines that the fair value of the reporting unit is not less than its carrying value, then performing the additional two-step impairment test is unnecessary. If the carrying value of goodwill exceeds its fair value, an impairment charge is recognized. The Company determined that its goodwill, with a balance of $2.9 million, was not impaired at December 31, 2018 after management performed its impairment tests. Derivative Instruments The 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 Base 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 Management 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 The General Partner has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “IRS Code”). As a REIT, the General Partner generally will not be subject to corporate federal income tax on net income that it currently distributes to its shareholders, provided that the General Partner 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 General Partner retains and does not distribute any net capital gains, the General Partner will be required to pay federal, state and local taxes, as applicable, on such net capital gains at the rate applicable to capital gains of a corporation.  The Operating Partnership is a partnership, and, as a result, all income and losses of the partnership are allocated to the partners for inclusion in their respective tax returns. Accordingly, no provision or benefit for income taxes has been made in the accompanying financial statements.  As of December 31, 2018 , the estimated net basis of the rental property for federal income tax purposes was lower than the net assets as reported in the Operating Partnership’s financial statements by approximately $410,573,000 . The Operating Partnership’s taxable income for the year ended December 31, 2018 was estimated to be approximately $82,106,000 and for the years ended December 31, 2017 and 2016 was approximately $97,037,000 and $30,208,000 , respectively. The differences between book income and taxable income primarily result from differences in depreciation expenses, the recording of rental income, differences in the deductibility of interest expense and certain other expenses for tax purposes, differences in revenue recognition and the rules for tax purposes of a property exchange.  The General Partner has elected to treat certain of its corporate subsidiaries as taxable REIT subsidiaries (each a “TRS”). In general, a TRS of the General Partner 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 General Partner 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.  The deferred tax asset balance at December 31, 2018 amounted to $ 10.1 million which has been fully reserved through a valuation allowance. New tax reform legislation enacted in late 2017 reduced the corporate tax rate to 21 percent, effective January 1, 2018. Consequently, the Company’s deferred tax assets were re-measured to reflect the reduction in the future U.S. corporate income tax rate as of the enactment date. As a result, the Company recorded a decrease related to its deferred tax assets of $5.3 million and a decrease to the associated valuation allowance of $5.3 million at December 31, 2017. If the General Partner fails to qualify as a REIT in any taxable year, the Company will be subject to federal income 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 December 31, 2018 , the tax years that remain subject to examination by the major tax jurisdictions under the statute of limitations are generally from the year 2014 forward.  Earnings Per Share or Unit The Company presents both basic and diluted earnings per share or unit (“EPS or EPU”). Basic EPS or EPU excludes dilution and is computed by dividing net income available to common shareholders or unitholders by the weighted average number of shares or units outstanding for the period. Diluted EPS or EPU 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 or EPU from continuing operations amount. Shares or Units whose issuance is contingent upon the satisfaction of certain conditions shall be considered outstanding and included in the computation of diluted EPS or EPU as follows (i) if all necessary conditions have been satisfied by the end of the period (the events have occurred), those shares or units 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 or units included in diluted EPS or EPU shall be based on the number of shares or units, 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 or units 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 or units shall be included in the denominator of diluted EPS or EPU as of the beginning of the period (or as of the date of the grant, if later).  Dividends and Distributions Payable The dividends and distributions payable at December 31, 2018 represents dividends payable to common shareholders ( 90,320,408 shares) and distributions payable to noncontrolling interest unitholders of the Operating Partnership ( 10,174,285 common units and 1,762,170 LTIP units) for all such holders of record as of January 3, 2019 with respect to the fourth quarter 2018 . The fourth quarter 2018 common stock dividends and unit distributions of $ 0.20 per common share, common unit and LTIP unit were approved by the General Partner’s Board of Directors on December 11, 2018 and paid on January 11, 2019 .  The dividends and distributions payable at December 31, 2017 represents dividends payable to common shareholders ( 89,914,658 shares) and distributions payable to noncontrolling interest unitholders of the Operating Partnership ( 10,438,855 common units and 1,230,877 LTIP units) for all such holders of record as of January 3, 2018 with respect to the fourth quarter 2017 . The fourth quarter 2017 common stock dividends and unit distributions of $ 0.20 per common share, common unit and LTIP unit were approved by the General Partner’s Board of Directors on December 12, 2017 and paid on January 12, 2018 .  The Company has determined that the $ 0.80 dividend per common share paid during the year ended December 31, 2018 represented approximately 47 percent ordinary income and approximately 53 percent capital gain; the $ 0.70 dividend per common share paid during the year ended December 31, 2017 represented 100 percent ordinary income and the $ 0.60 dividend per common share paid during the year ended December 31, 2016 represented 100 percent return of capital.  Costs Incurred For Stock Issuances Costs incurred in connection with the Company’s stock issuances are reflected as a reduction of additional paid ‑in capital.  Stock Compensation The 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”), performance share units, long term incentive plan awards and stock options at the grant date be amortized ratably into expense over the appropriate vesting period. The Company recorded stock compensation expense of $ 6,894,000 , $ 7,447,000 and $ 5,646,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively.  Other Comprehensive Income (Loss) Other comprehensive income (loss) includes items that are recorded in equity, such as effective portions of derivatives designated as cash flow hedges or unrealized holding gains or losses on marketable securities available for sale.  Redeemable Noncontrolling Interests The Company evaluates the terms of the partnership units issued in accordance with the FASB’s Distinguishing Liabilities from Equity guidance. Units which embody an unconditional obligation requiring the Company to redeem the units for cash after a specified or determinable date (or dates) or upon the occurrence of an event that is not solely within the control of the issuer are determined to be contingently redeemable under this guidance and are included as Redeemable noncontrolling interests and classified within the mezzanine section between Total liabilities and Stockholders’ equity on the Company’s Consolidated Balance Sheets. The carrying amount of the redeemable noncontrolling interests will be changed by periodic accretions, so that the carrying amount will equal the estimated future redemption value at the redemption date.  Fair Value Hierarchy The 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.  Impact Of Recently-Issued Accounting Standards In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), modifying the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). ASU 2016-02 provides new guidelines that change the accounting for leasing arrangements for lessees, whereby their rights and obligations under substantially all leases, existing and new, would be capitalized and recorded on the balance sheet. For lessors, however, the accounting remains largely equivalent to the current model, with the distinction between operating, sales-type, and direct financing leases retained, but updated to align with certain changes to the lessee model and the new revenue recognition standard.  ASU 2016-02 provides two transition methods. The first transition method allows for application of the new model at the beginning of the earliest comparative period presented. Under the second transition method, comparative periods would not be restated, with any cumulative effect adjustments recognized in the opening balance of retained earnings in the period of adoption. In addition, a practical expedient was recently issued by the FASB that allows lessors to combine non-lease components with related lease components if certain conditions are met. The Company will adopt this guidance for its interim and annual pe
Mack-Cali Realty LP [Member]
Significant Accounting Policies [Line Items]
Significant Accounting Policies	2. SIGNIFICANT ACCOUNTING POLICIES  Rental Property Rental 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 were expensed as incurred for all real estate acquisitions classified as business combinations, which were substantially all of our operating property acquisitions, through December 31, 2016. The Company early adopted FASB guidance Accounting Standards Update (“ASU”) 2017-01 on January 1, 2017, which revises the definition of a business and is expected to result in more transactions to be accounted for as asset acquisitions and significantly limit transactions that would be accounted for as business combinations. Where an acquisition has been determined to be an asset acquisition, acquisition-related costs are capitalized. 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 $ 2.3 million, $ 2.2 million and $2.6 million for the years ended December 31, 2018 , 2017 and 2016 , 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.  Included in net investment in rental property as of December 31, 2018 and December 31, 2017 is real estate and building and tenant improvements not in service; as follows (dollars in thousands) :     December 31, December 31,  2018 2017  Land held for development (including pre-development costs) (a) $ 465,930 $ 483,432  Development and construction in progress, including land (b) 327,039 535,971  Total $ 792,969 $ 1,019,403  (a) Includes predevelopment and infrastructure costs included in buildings and improvements of $204.9 million and $188.1 million as of December 31, 2018 and December 31, 2017, respectively. (b) Includes land of $49.6 million and $77.0 million as of December 31, 2018 and December 31, 2017, respectively.  The Company considers a construction project as substantially completed and held available for occupancy upon the substantial completion of 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 residents, 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 commercial square footage or multi-family units 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 relative fair values. The Company records goodwill or a gain on bargain purchase (if any) if the net assets acquired/liabilities assumed differ from the purchase consideration of a business 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 or leases.  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, current and historical operating and/or cash flow losses, near-term mortgage debt maturities and/or other factors, including those 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 impairment loss shall be measured as the excess of the carrying value 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 When 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. The Company generally considers assets to be held for sale when the transaction has received appropriate corporate authority, and there are no significant contingencies relating to the sale. If, in management’s opinion, the estimated net sales price, net of selling costs, of the assets which have been identified as held for sale is less than the carrying value of the assets, a valuation allowance (which is recorded as unrealized losses on disposition of rental property) 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 value 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 The 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.  If the venture subsequently makes distributions and the Company does not have an implied or actual commitment to support the operations of the venture, including a general partner interest in the investee, the Company will not record a basis less than zero, rather such amounts will be recorded as equity in earnings of unconsolidated joint ventures. 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 value 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 All highly liquid investments with an original maturity of three months or less when purchased are considered to be cash equivalents. Deferred Financing Costs Costs incurred in obtaining financing are capitalized and amortized over the term of the related indebtedness. Deferred financing costs are presented in the balance sheet as a direct deduction from the carrying value of the debt liability to which they relate, except deferred financing costs related to the revolving credit facility, which are presented in deferred charges, goodwill and other assets. In all cases, amortization of such costs is included in interest expense and was $ 5,028,000 , $ 4,612,000 and $ 4,582,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. If a financing obligation is extinguished early, any unamortized deferred financing costs are written off and included in gains (losses) from extinguishment of debt. Included in loss from extinguishment of debt, net of gains, of $10.8 million, $0.4 million and $ 30.5 million for the years ended December 31, 2018 , 2017 and 2016 were unamortized deferred financing costs which were written off (as non-cash transactions) amounting to $0.6 million, $ 0.4 million and $ 0.7 million, respectively. Deferred Leasing Costs Costs incurred in connection with successfully executed commercial and residential 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, and included in deferred charges, goodwill and other assets, net was approximately $ 3,463,000 , $ 3,146,000 and $ 3,270,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. Upon the adoption of ASC842 on January1, 2019, the Company will no longer capitalize such costs. Goodwill Goodwill 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 value 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 value. If, based on this assessment, management determines that the fair value of the reporting unit is not less than its carrying value, then performing the additional two-step impairment test is unnecessary. If the carrying value of goodwill exceeds its fair value, an impairment charge is recognized. The Company determined that its goodwill, with a balance of $2.9 million, was not impaired at December 31, 2018 after management performed its impairment tests. Derivative Instruments The 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 Base 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 Management 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 The General Partner has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “IRS Code”). As a REIT, the General Partner generally will not be subject to corporate federal income tax on net income that it currently distributes to its shareholders, provided that the General Partner 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 General Partner retains and does not distribute any net capital gains, the General Partner will be required to pay federal, state and local taxes, as applicable, on such net capital gains at the rate applicable to capital gains of a corporation.  The Operating Partnership is a partnership, and, as a result, all income and losses of the partnership are allocated to the partners for inclusion in their respective tax returns. Accordingly, no provision or benefit for income taxes has been made in the accompanying financial statements.  As of December 31, 2018 , the estimated net basis of the rental property for federal income tax purposes was lower than the net assets as reported in the Operating Partnership’s financial statements by approximately $410,573,000 . The Operating Partnership’s taxable income for the year ended December 31, 2018 was estimated to be approximately $82,106,000 and for the years ended December 31, 2017 and 2016 was approximately $97,037,000 and $30,208,000 , respectively. The differences between book income and taxable income primarily result from differences in depreciation expenses, the recording of rental income, differences in the deductibility of interest expense and certain other expenses for tax purposes, differences in revenue recognition and the rules for tax purposes of a property exchange.  The General Partner has elected to treat certain of its corporate subsidiaries as taxable REIT subsidiaries (each a “TRS”). In general, a TRS of the General Partner 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 General Partner 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.  The deferred tax asset balance at December 31, 2018 amounted to $ 10.1 million which has been fully reserved through a valuation allowance. New tax reform legislation enacted in late 2017 reduced the corporate tax rate to 21 percent, effective January 1, 2018. Consequently, the Company’s deferred tax assets were re-measured to reflect the reduction in the future U.S. corporate income tax rate as of the enactment date. As a result, the Company recorded a decrease related to its deferred tax assets of $5.3 million and a decrease to the associated valuation allowance of $5.3 million at December 31, 2017. If the General Partner fails to qualify as a REIT in any taxable year, the Company will be subject to federal income 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 December 31, 2018 , the tax years that remain subject to examination by the major tax jurisdictions under the statute of limitations are generally from the year 2014 forward.  Earnings Per Share or Unit The Company presents both basic and diluted earnings per share or unit (“EPS or EPU”). Basic EPS or EPU excludes dilution and is computed by dividing net income available to common shareholders or unitholders by the weighted average number of shares or units outstanding for the period. Diluted EPS or EPU 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 or EPU from continuing operations amount. Shares or Units whose issuance is contingent upon the satisfaction of certain conditions shall be considered outstanding and included in the computation of diluted EPS or EPU as follows (i) if all necessary conditions have been satisfied by the end of the period (the events have occurred), those shares or units 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 or units included in diluted EPS or EPU shall be based on the number of shares or units, 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 or units 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 or units shall be included in the denominator of diluted EPS or EPU as of the beginning of the period (or as of the date of the grant, if later).  Dividends and Distributions Payable The dividends and distributions payable at December 31, 2018 represents dividends payable to common shareholders ( 90,320,408 shares) and distributions payable to noncontrolling interest unitholders of the Operating Partnership ( 10,174,285 common units and 1,762,170 LTIP units) for all such holders of record as of January 3, 2019 with respect to the fourth quarter 2018 . The fourth quarter 2018 common stock dividends and unit distributions of $ 0.20 per common share, common unit and LTIP unit were approved by the General Partner’s Board of Directors on December 11, 2018 and paid on January 11, 2019 .  The dividends and distributions payable at December 31, 2017 represents dividends payable to common shareholders ( 89,914,658 shares) and distributions payable to noncontrolling interest unitholders of the Operating Partnership ( 10,438,855 common units and 1,230,877 LTIP units) for all such holders of record as of January 3, 2018 with respect to the fourth quarter 2017 . The fourth quarter 2017 common stock dividends and unit distributions of $ 0.20 per common share, common unit and LTIP unit were approved by the General Partner’s Board of Directors on December 12, 2017 and paid on January 12, 2018 .  The Company has determined that the $ 0.80 dividend per common share paid during the year ended December 31, 2018 represented approximately 47 percent ordinary income and approximately 53 percent capital gain; the $ 0.70 dividend per common share paid during the year ended December 31, 2017 represented 100 percent ordinary income and the $ 0.60 dividend per common share paid during the year ended December 31, 2016 represented 100 percent return of capital.  Costs Incurred For Stock Issuances Costs incurred in connection with the Company’s stock issuances are reflected as a reduction of additional paid ‑in capital.  Stock Compensation The 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”), performance share units, long term incentive plan awards and stock options at the grant date be amortized ratably into expense over the appropriate vesting period. The Company recorded stock compensation expense of $ 6,894,000 , $ 7,447,000 and $ 5,646,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively.  Other Comprehensive Income (Loss) Other comprehensive income (loss) includes items that are recorded in equity, such as effective portions of derivatives designated as cash flow hedges or unrealized holding gains or losses on marketable securities available for sale.  Redeemable Noncontrolling Interests The Company evaluates the terms of the partnership units issued in accordance with the FASB’s Distinguishing Liabilities from Equity guidance. Units which embody an unconditional obligation requiring the Company to redeem the units for cash after a specified or determinable date (or dates) or upon the occurrence of an event that is not solely within the control of the issuer are determined to be contingently redeemable under this guidance and are included as Redeemable noncontrolling interests and classified within the mezzanine section between Total liabilities and Stockholders’ equity on the Company’s Consolidated Balance Sheets. The carrying amount of the redeemable noncontrolling interests will be changed by periodic accretions, so that the carrying amount will equal the estimated future redemption value at the redemption date.  Fair Value Hierarchy The 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.  Impact Of Recently-Issued Accounting Standards In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), modifying the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). ASU 2016-02 provides new guidelines that change the accounting for leasing arrangements for lessees, whereby their rights and obligations under substantially all leases, existing and new, would be capitalized and recorded on the balance sheet. For lessors, however, the accounting remains largely equivalent to the current model, with the distinction between operating, sales-type, and direct financing leases retained, but updated to align with certain changes to the lessee model and the new revenue recognition standard.  ASU 2016-02 provides two transition methods. The first transition method allows for application of the new model at the beginning of the earliest comparative period presented. Under the second transition method, comparative periods would not be restated, with any cumulative effect adjustments recognized in the opening balance of retained earnings in the period of adoption. In addition, a practical expedient was recently issued by the FASB that allows lessors to combine non-lease components with related lease components if certain conditions are met. The Company will adopt this guidance for its interim and annual pe

Recent Transactions

Recent Transactions	12 Months Ended
	Dec. 31, 2018
Recent Transactions [Line Items]
Recent Transactions	3. RECENT TRANSACTIONS  Management Changes In March 2018, the Company announced the appointment of Michael J. DeMarco, Chief Executive Officer of the General Partner, to its Board of Directors effective March 14, 2018. Mr. DeMarco’s addition to the Board expanded the total number of members from nine to ten . In February 2019, the Company announced that the Board of Directors increased its size from ten to eleven members, effective immediately, and nominated a slate of eleven candidates consisting of Lisa Myers, Laura Pomerantz and all of the current directors of the Company (other than Kenneth M. Duberstein, who decided not to stand for re-election and will retire from the Board of Directors at the Company’s 2019 annual meeting of shareholders) for election to the Board of Directors at the Company’s 2019 annual meeting of shareholders, which is expected to be held on June 12, 2019.  In January 2018, the Company announced the appointment of David J. Smetana as chief financial officer and Nicholas Hilton as executive vice president of leasing of the General Partner. Mr. Smetana began to perform his duties as chief financial officer and Anthony Krug ceased to serve as chief financial officer immediately following the filing of the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Mr. Krug remained an employee of the Company and provided transition services through March 31, 2018. Mr. Hilton’s employment commenced on February 12, 2018 following the departure of Christopher DeLorenzo.  In June 2018, the Company announced that the employment of Mitchell E. Rudin as Vice Chairman of the General Partner was terminated effective as of June 5, 2018. In November 2018, the Company announced that the employment of Robert Andrew Marshall as President and Executive Vice President of Development of RRT was terminated effective as of October 31, 2018. In addition, the Company also restructured certain other corporate and property management personnel during the year ended December 31, 2018.  As a result of the executive management changes as well as other personnel changes during the period, the Company incurred total net severance and related expenses in the year ended December 31, 2018 of $7.9 million, $6.5 million of which was included in general and administrative expense (including $1.0 million of stock compensation expense due to accelerated vesting and a net reversal of $2.0 million of amortization of stock compensation expense due to the forfeiture of unvested securities) and $1.4 million of which was included in operating services expense for the period.  Acquisitions On February 6, 2019, the Company completed the acquisition of a 271,988 square foot office property located in Iselin, New Jersey, for a purchase price of $61.5 million, which was funded using funds available with the Company’s qualified intermediary and borrowings under the Company’s unsecured revolving credit facility.  On January 25, 2019, the Company signed an agreement to acquire a 377 -unit multi-family rental property located in Jersey City, New Jersey for approximately $264 million, subject to certain conditions. The acquisition is expected to be completed in the second quarter 2019.  2017 The Company acquired the following office properties (which were determined to be asset acquisitions in accordance with ASU 2017-01) during the year ended December 31, 2017 (dollars in thousands) :     Acquisition # of Rentable Acquisition  Date Property Address Location Bldgs. Square Feet Cost  01/11/17 Red Bank portfolio (a) Red Bank, New Jersey 3 279,472 $ 27,228  03/06/17 Short Hills/Madison portfolio (b) Short Hills & Madison, New Jersey 6 1,113,028 367,361   Total Acquisitions 9 1,392,500 $ 394,589   (a) This acquisition was funded through borrowings under the Company's unsecured revolving credit facility.  (b) This acquisition was funded through borrowings under the Company’s unsecured revolving credit facility and a new $124.5 million loan secured by three of the properties.  The purchase prices were allocated to the net assets acquired, as follows (in thousands) :     Red Bank Short Hills/Madison  Portfolio Portfolio Total  Land and leasehold interest $ 7,914 $ 30,336 $ 38,250  Buildings and improvements and other assets 16,047 295,299 311,346  Above market leases (a) 118 6,367 6,485  In-place lease values (a) 3,171 45,604 48,775  27,250 377,606 404,856  Less: Below market lease values (a) (22) (10,245) (10,267)  Net assets recorded upon acquisition $ 27,228 $ 367,361 $ 394,589  (a) Above market, in-place and below market leases are being amortized over a weighted-average term of 5.4 years.  The Company acquired three separate developable land parcels located in Jersey City, Morris Township and Red Bank, New Jersey, for approximately $80 million during the year ended December 31, 2017. The acquisitions were funded using available cash and borrowings under the Company’s unsecured revolving credit facility.  Properties Commencing Initial Operations The following properties commenced initial operations during the year ended December 31, 2018 ( dollars in thousands ):     # of Total  In-Service Apartment Units/ Development  Date Property Location Type Rooms Costs Incurred  03/01/18 145 Front at City Square Worcester, MA Multi-Family 365 $ 97,483 (a)  04/01/18 Signature Place at Morris Plains Morris Plains, NJ Multi-Family 197 56,715 (b)  05/01/18 Portside 5/6 East Boston, MA Multi-Family 296 114,694 (c)  08/01/18 RiverHouse 11 at Port Imperial Weehawken, NJ Multi-Family 295 130,369 (d)  12/13/18 Residence Inn By Marriott (Phase I) Weehawken, NJ Hotel 164 58,723 (e)  Totals 1,317 $ 457,984 (a) Development costs as of December 31, 2018 included approximately $4.4 in land costs. As of December 31, 2018, the Company anticipates additional costs of approximately $1.1 million, which will be primarily funded from a construction loan. (b) Development costs as of December 31, 2018 included approximately $0.9 in land costs. (c) As of December 31, 2018 , the Company anticipates additional costs of approximately $0.7 million, which will be funded by the Company. (d) As of December 31, 2018 , the Company anticipates additional costs of $1.2 million which will be funded by the Company. (e) As of December 31, 2018, the Company anticipates additional costs of $20.1 million which will be funded from a construction loan.  Consolidations 2018 On August 2, 2018, the Company, which held a 24.27 percent subordinated interest in the unconsolidated joint venture Marbella Tower Urban Renewal Associates LLC, a 412 -unit multi-family operating property located in Jersey City, New Jersey, acquired its equity partner’s 50 percent interest for $65.6 million in cash. The property was subject to a mortgage loan that had a principal balance of $95 million. The cash portion of the acquisition was funded primarily through borrowings under the Company's unsecured revolving credit facility. Concurrently with the closing, the joint venture repaid the $95 million mortgage loan in full and obtained a new loan from a different lender, collateralized by the property in the amount of $131 million, which bears interest at 4.07 percent and matures in August 2026 . The venture distributed $37.4 million of the loan proceeds, of which the Company’s share was $30.4 million. As a result of the acquisition, the Company increased its ownership of the property from a 24.27 percent subordinated interest to a 74.27 percent controlling interest. In accordance with ASC 810, Consolidation, the Company evaluated the acquisition and determined that the entity meets the criteria of a VIE. As such, the Company consolidated the asset upon acquisition and accordingly, remeasured its equity interests, as required by the FASB's consolidation guidance, at fair value (based upon the income approach using current rates and market cap rates and discount rates). As a result, the Company recorded a gain on change of control of interests of $14.2 million (a non-cash item) in the year ended December 31, 2018 , when the Company accounted for the transaction as a VIE that is not a business in accordance with ASC 810-10-30-4. Additional non-cash items included in the acquisition were the Company’s carrying value of its interest in the joint venture of $14 million and the noncontrolling interest’s fair value of $29.8 million (non-cash allocation). See Note 9: Mortgages, Loans Payable and Other Obligations.  Net assets recorded upon consolidation were as follows (in thousands) :     Land and leasehold interest $ 48,820  Buildings and improvements and other assets, net 162,958  In-place lease values (a) 6,947  Less: Below market lease values (a) (108)  218,617  Less: Debt (131,000)  Net Assets 87,617  Less: Noncontrolling interest (b) (22,812)  Net assets recorded upon consolidation $ 64,805   (a) In-place and below market leases are being amortized over a weighted-average term of 9.3 months.  (b) Noncontrolling interest balance reflects distribution of $7.0 million of loan proceeds at closing.  2017 On February 3, 2017, the Operating Partnership issued 42,800 shares of a new class of 3.5 percent Series A Preferred Limited Partnership Units of the Operating Partnership (the “Series A Units”) valued at $42.8 million. The Series A Units were issued to the Company’s partners in the Plaza VIII & IX Associates L.L.C. joint venture that owns a development site adjacent to the Company’s Harborside property in Jersey City, New Jersey as non-cash consideration for their approximate 37.5 percent interest in the joint venture. Concurrent with the issuance of the Series A Units, the Company purchased from other partners in the Plaza VIII & IX Associates L.L.C. joint venture their approximate 12.5 percent interest for approximately $14.3 million in cash. The results of these transactions increased the Company’s interests in the joint venture from 50 percent to 100 percent. Upon these acquisitions, the Company consolidated Plaza VIII & IX Associates L.L.C., a voting interest entity, substantially all of which is comprised of land for development. As an acquisition of the additional 50 percent of the land, the Company accounted for the transaction as an asset acquisition under a cost accumulation model, resulting in total consolidated assets of $60.6 million, substantially all of which is classified as land on the Balance Sheet.  On February 28, 2017, the Operating Partnership authorized the issuance of 9,213 shares of a new class of 3.5 percent Series A-1 Preferred Limited Partnership Units of the Operating Partnership (the “Series A-1 Units”). 9,122 Series A-1 Units were issued on February 28, 2017, valued at $9.1 million, to the Company’s partner in a joint venture with the Operating Partnership, which owns Monaco Towers in Jersey City, New Jersey that includes 523 apartment homes in two fifty -story towers with 558 parking spaces and 12,300 square feet of ground floor retail space. The Series A-1 Units were issued as non-cash consideration for the partner’s approximate 13.8 percent ownership interest in the joint venture to increase the Company’s unconsolidated investment to 29 percent. In April 2017, an additional 91 Series A-1 Units were issued by the Operating Partnership to purchase from other partners in the same joint venture their approximate 71.2 percent ownership interest for approximately $130.9 million in cash and $171.2 million in assumed debt in transactions which closed in April 2017. The results of these transactions increased the Company’s interests in the joint venture to 100 percent. Upon these acquisitions, the Company consolidated RoseGarden Monaco Holdings, L.L.C., a voting interest entity.  As an acquisition of the remaining interests in the venture which owns the Monaco Towers, the Company accounted for the transaction as an asset acquisition under a cost accumulation model, resulting in total consolidated net assets of $139.9 million which is allocated, as follows (in thousands):     Monaco Monaco  North South Total  Land and leasehold interest $ 27,300 $ 31,461 $ 58,761  Buildings and improvements and other assets 112,841 129,895 242,736  Above market leases (a) 350 - 350  In-place lease values (a) 4,585 4,913 9,498  Less: Below market lease values (a) (141) (118) (259)  144,935 166,151 311,086  Less: Debt assumed at fair value (79,544) (91,656) (171,200)  Net assets recorded upon consolidation $ 65,391 $ 74,495 $ 139,886  (a) Above market, in-place and below market leases are being amortized over a weighted-average term of 8 months .  Dispositions/Rental Property Held for Sale  2018 The Company disposed of the following office properties during the year ended December 31, 2018 (dollars in thousands) :     Realized  Gains  Rentable Net Net (losses)/  Disposition # of Square Sales Carrying Unrealized  Date Property/Address Location Bldgs. Feet Proceeds Value Losses, net  02/15/18 35 Waterview Boulevard (a) Parsippany, New Jersey 1 172,498 $ 25,994 $ 25,739 $ 255  03/05/18 Hamilton portfolio (b) Hamilton, New Jersey 6 239,262 17,546 17,501 45  03/07/18 Wall portfolio first closing Wall, New Jersey 5 179,601 14,053 10,526 3,527  03/22/18 700 Horizon Drive Hamilton, New Jersey 1 120,000 33,020 16,053 16,967  03/23/18 Wall portfolio second closing Wall, New Jersey 3 217,822 30,209 12,961 17,248  03/28/18 75 Livingston Avenue Roseland, New Jersey 1 94,221 7,983 5,609 2,374  03/28/18 20 Waterview Boulevard (c) Parsippany, New Jersey 1 225,550 12,475 11,795 680  03/30/18 Westchester Financial Center (d) White Plains, New York 2 489,000 81,769 64,679 17,090  06/27/18 65 Jackson Drive Cranford, New Jersey 0 - 1,510 (e) - 1,510  08/02/18 600 Horizon Drive Hamilton, New Jersey 1 95,000 15,127 6,191 8,936  09/05/18 1 & 3 Barker Avenue White Plains, New York 2 133,300 15,140 13,543 1,597  11/15/18 120 Passaic Street (f) Rochelle Park, New Jersey 1 52,000 2,667 2,568 99  12/31/18 Elmsford Distribution Center Elmsford, New York 6 387,400 66,557 17,314 49,243  Sub-total 30 2,405,654 324,050 204,479 119,571   Unrealized losses on rental property held for sale (20,135)  Totals 30 2,405,654 $ 324,050 $ 204,479 $ 99,436   (a) The Company recorded a valuation allowance of $0.7 million on this property during the year ended December 31, 2017.  (b) The Company recorded a valuation allowance of $0.6 million on these properties during the year ended December 31, 2017. The disposition additionally included two land properties.  (c) The Company recorded a valuation allowance of $11 million on this property during the year ended December 31, 2017. Prior to closing, the Company provided short term financing through a note receivable  to an affiliate of the buyers of $2.8 million. The note was paid off in the second quarter of 2018.  (d) Prior to closing, the Company provided financing through a note receivable to an affiliate of the buyers of $4.0 million. The note was paid off in October 2018.  (e) Represents the receipt by the Company in the second quarter 2018 of variable contingent sales consideration, net of costs, of $1.5 million subsequent to disposition of the property sold in January 2017.  (f) The net sale proceeds were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2018. See Note 5: Deferred Charges,  Goodwill and Other Assets, Net).  The Company disposed of the following developable land holding during the year ended December 31, 2018 (dollars in thousands) :     Net Net Gain on  Disposition Sales Carrying Disposition of  Date Property Address Location Proceeds Value Developable Land  12/31/18 One Lake Street Upper Saddle River, New Jersey (a) $ 46,036 $ 15,097 $ 30,939   Totals $ 46,036 $ 15,097 $ 30,939   (a) The net sale proceeds were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2018. See Note 5: Deferred  Charges, Goodwill and Other Assets, Net. The net carrying value includes $3 million of development costs funded at the closing.  The Company identified as held for sale six office properties, totaling approximately 845,000 square feet, and a 159 unit multi-family rental property as of December 31, 2018 . The properties are located in Fort Lee, Newark, Paramus, Bridgewater, Morris Plains and Rahway, New Jersey. The total estimated sales proceeds, net of expected selling costs, from the sales are expected to be approximately $124 million. The Company determined that the carrying value of four of the properties was not expected to be recovered from estimated net sales proceeds and accordingly recognized an unrealized loss allowance of $20.1 million for the year ended December 31, 2018 . In January 2019, the Company completed the disposition of three of these properties for sales proceeds of approximately $54.5 million.  The following table summarizes the rental property held for sale, net, as of December 31, 2018 (dollars in thousands):     December 31,  2018  Land $ 24,376  Buildings and improvements 159,857  Less: Accumulated depreciation (55,250)  Less: Unrealized losses on properties held for sale (20,135)  Rental property held for sale, net $ 108,848  Other assets and liabilities related to the rental properties held for sale, as of December 31, 2018, include $2.9 million in Deferred charges and other assets, $1.7 million in Unbilled rents receivable and $ 2.3 million in Accounts payable, accrued expenses and other liabilities. Approximately $3.9 million of these assets and $ 1.7 million of these liabilities are expected to be removed with the completion of the sales.  2017 The Company disposed of the following office properties during the year ended December 31, 2017 (dollars in thousands) :     Realized  Gains  Rentable Net Net (losses)/  Disposition # of Square Sales Carrying Unrealized  Date Property/Address Location Bldgs. Feet Proceeds Value Losses, net  01/30/17 Cranford portfolio Cranford, New Jersey 6 435,976 $ 26,598 $ 22,736 $ 3,862  01/31/17 440 Route 22 East (a) Bridgewater, New Jersey 1 198,376 10,074 10,069 5  02/07/17 3 Independence Way Princeton, New Jersey 1 111,300 11,549 9,910 1,639  05/15/17 103 Carnegie Center Princeton, New Jersey 1 96,000 15,063 8,271 6,792  08/29/17 400 Chestnut Ridge Road Woodcliff Lake, New Jersey 1 89,200 6,891 7,498 (607)  08/30/17 140 E. Ridgewood Avenue Paramus, New Jersey 1 239,680 30,201 30,737 (536)  08/30/17 Bergen portfolio Woodcliff Lake, Paramus and 5 1,061,544 86,973 (c) 135,121 (48,148)  Rochelle Park, New Jersey  09/11/17 377 Summerhill Road East Brunswick, New Jersey 1 40,000 3,221 2,172 1,049  09/13/17 700 Executive Boulevard Elmsford, New York - - (b) 5,717 970 4,747  09/20/17 Totowa Portfolio Totowa, New Jersey 13 499,243 63,624 27,630 35,994  09/27/17 890 Mountain Avenue (d) New Providence, New Jersey 1 80,000 4,852 6,139 (1,287)  09/28/17 135 Chestnut Ridge Road Montvale, New Jersey 1 66,150 5,844 (e) 2,929 2,915  09/29/17 Moorestown portfolio Moorestown and Burlington, New Jersey 26 1,260,398 73,393 (f) 56,186 17,207  10/19/17 1 Enterprise Boulevard Yonkers, New York - - (b) 3,230 1,380 1,850  11/15/17 61 South Paramus Road Paramus, New Jersey 1 269,191 23,255 37,184 (13,929)  12/06/17 300 Tice Boulevard Woodcliff Lake, New Jersey 1 230,000 28,847 25,705 3,142  Sub-total 60 4,677,058 399,332 384,637 14,695   Unrealized losses on rental property held for sale (12,331)   Totals 60 4,677,058 $ 399,332 $ 384,637 $ 2,364   (a) The Company recorded a valuation allowance of $7.7 million on this property during the year ended December 31, 2016.  (b) This disposition is of a ground leased land property.  (c) At closing, the Company provided short term seller financing aggregating $65 million through mortgage notes receivable to the buyers. These notes were paid off in November  and December 2017.  (d) The Company recorded an impairment charge of $7.0 million on this property during the year ended December 31, 2015.  (e) The Company recorded an impairment charge of $4.2 million on this property during the year ended December 31, 2015. $5.9 million of the sales proceeds from this sale were  held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2017. The Company received these proceeds in  March 2018. See Note 5: Deferred Charges, Goodwill and Other Assets, Net.  (f) $15.3 million of the sales proceeds from this sale were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets  as of December 31, 2017. The Company received these proceeds in March 2018. See Note 5: Deferred Charges, Goodwill and Other Assets, Net.  The Company identified as held for sale 21 office properties totaling approximately 2 million square feet as of December 31, 2017. The properties are located in Parsippany, Paramus, Rochelle Park, Hamilton and Wall, New Jersey and White Plains, New York. The total estimated sales proceeds from the sales were expected to be approximately $223 million. The Company determined that the carrying value of seven of the office properties was not expected to be recovered from estimated net sales proceeds and accordingly recognized an unrealized loss allowance of $12.3 million during the year ended December 31, 2017.  The following table summarizes the rental property held for sale, net, as of December 31, 2017 (dollars in thousands):     December 31,  2017  Land $ 37,024  Buildings and improvements 273,388  Less: Accumulated depreciation (126,503)  Less: Unrealized losses on properties held for sale (12,331)  Rental property held for sale,net $ 171,578   Other assets and liabilities related to the rental properties held for sale, as of December 31, 2017, included $9.8 million in deferred charges, and other assets, $4.7 million in Unbilled rents receivable and $ 4.6 million in Accounts payable, accrued expenses and other liabilities. Approximately $13.4 million of these assets and $ 0.3 million of these liabilities were expected to be written off with the completion of the sales.  Land Impairments The Company owns two separate developable land parcels in Conshohocken and Bala Cynwyd, Pennsylvania, that were being considered for development into multi-family rental properties. During the fourth quarter 2018, the Company made the decision to pursue selling the land parcels as opposed to development. Due to the shortening of the expected periods of ownership, the Company determined that it was necessary to reduce the carrying values of the land parcels to their estimated fair values (ascertained by broker opinions of value obtained during the marketing process) and recorded total land impairments charges of $24.6 million at December 31, 2018.  Rockpoint Transaction On February 27, 2017, the Company, RRT, the Company’s wholly-owned subsidiary through which the Company conducts its multi-family residential real estate operations, Roseland Residential, L.P. (“RRLP”), the operating partnership through which RRT conducts all of its operations, and certain other affiliates of the Company entered into an equity investment agreement (the “Investment Agreement”) with Rockpoint Group, L.L.C. and certain of its affiliates (collectively, “Rockpoint”). The Investment Agreement provides for multiple equity investments by Rockpoint in RRLP from time to time for up to an aggregate of $300 million of equity units of limited partnership interests of RRLP (the “Rockpoint Units”). The initial closing under the Investment Agreement occurred on March 10, 2017 for $150 million of Rockpoint Units. Additional closings of Rockpoint Units to be issued and sold to Rockpoint pursuant to the Investment Agreement may occur from time to time in increments of not less than $10 million per closing, with the balance of the full $300 million by March 1, 2019. See Note 14: Redeemable Noncontrolling Interests.  RRLP has been identified as a variable interest entity in which the Company is deemed to be the primary beneficiary. As of December 31, 2018 and December 31, 2017, the Company’s consolidated RRLP entity had total assets of $2.3 billion and $1.9 billion, respectively, total mortgages and loan payable of $1.1 billion and $769.7 million, respectively, and other liabilities of $57 million and $95.9 million, respectively.  Unconsolidated Joint Venture Activity On January 31, 2019, the Company, which held a 24.27 percent subordinated interest in the unconsolidated joint venture Marbella Tower Urban Renewal Associates South LLC, a 311-unit multi-family operating property located in Jersey City, New Jersey, acquired its equity partner’s 50 percent interest for $77.5 million in cash. The acquisition was funded primarily using available cash. Concurrently with the closing, the joint venture repaid in full the property’s $74.7 million mortgage loan and obtained a new loan in the amount of $117 million.  On December 11, 2018, the Company acquired one of its partner’s interest in the Metropolitan and Shops at 40 Park and the Lofts at 40 Park for $1.3 million and as a result, increased its ownership from 12.5 percent interest to 25 percent interest in the Metropolitan and Shops at 40 Park and from 25 percent interest to 50 percent interest in the Lofts at 40 Park.  On September 29, 2017, the Company sold its interests in the KPG-MCG Curtis joint venture that owns an operating property located in Philadelphia, Pennsylvania for a sales price of $102.5 million, which included the retirement of the Company’s share in a mortgage payable of $75 million, and realized a gain on the sale of the unconsolidated joint venture of $12 million. $5.6 million of the net sales proceeds from this sale were held by a qualified intermediary, which is considered non cash and recorded in deferred charges, goodwill and other assets. See Note 5: Deferred Charges, Goodwill and Other Assets, Net.   On September 21, 2017, the RoseGarden Monaco, L.L.C. joint venture agreement was terminated. Accordingly, the Company wrote off the carrying value of its investment in the joint venture and recorded a loss of $1.4 million on the disposition of its joint venture interest.  On February 15, 2017, the Company sold its 7.5 percent interest in the Elmajo Urban Renewal Associates, LLC and Estuary Urban Renewal Unit B, LLC joint ventures that own operating multi-family properties located in Weehawken, New Jersey for a sales price of $5.1 million and realized a gain on the sale of the unconsolidated joint venture of $5.1 million.  On January 31, 2017, the Company sold its interest in the KPG-P 100 IMW JV, LLC, Keystone-Penn and Keystone-Tristate joint ventures that own operating properties, located in Philadelphia, Pennsylvania for an aggregate sales price of $9.7 million and realized a gain on the sale of the unconsolidated joint venture of $7.4 million.
Mack-Cali Realty LP [Member]
Recent Transactions [Line Items]
Recent Transactions	3. RECENT TRANSACTIONS  Management Changes In March 2018, the Company announced the appointment of Michael J. DeMarco, Chief Executive Officer of the General Partner, to its Board of Directors effective March 14, 2018. Mr. DeMarco’s addition to the Board expanded the total number of members from nine to ten . In February 2019, the Company announced that the Board of Directors increased its size from ten to eleven members, effective immediately, and nominated a slate of eleven candidates consisting of Lisa Myers, Laura Pomerantz and all of the current directors of the Company (other than Kenneth M. Duberstein, who decided not to stand for re-election and will retire from the Board of Directors at the Company’s 2019 annual meeting of shareholders) for election to the Board of Directors at the Company’s 2019 annual meeting of shareholders, which is expected to be held on June 12, 2019.  In January 2018, the Company announced the appointment of David J. Smetana as chief financial officer and Nicholas Hilton as executive vice president of leasing of the General Partner. Mr. Smetana began to perform his duties as chief financial officer and Anthony Krug ceased to serve as chief financial officer immediately following the filing of the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Mr. Krug remained an employee of the Company and provided transition services through March 31, 2018. Mr. Hilton’s employment commenced on February 12, 2018 following the departure of Christopher DeLorenzo.  In June 2018, the Company announced that the employment of Mitchell E. Rudin as Vice Chairman of the General Partner was terminated effective as of June 5, 2018. In November 2018, the Company announced that the employment of Robert Andrew Marshall as President and Executive Vice President of Development of RRT was terminated effective as of October 31, 2018. In addition, the Company also restructured certain other corporate and property management personnel during the year ended December 31, 2018.  As a result of the executive management changes as well as other personnel changes during the period, the Company incurred total net severance and related expenses in the year ended December 31, 2018 of $7.9 million, $6.5 million of which was included in general and administrative expense (including $1.0 million of stock compensation expense due to accelerated vesting and a net reversal of $2.0 million of amortization of stock compensation expense due to the forfeiture of unvested securities) and $1.4 million of which was included in operating services expense for the period.  Acquisitions On February 6, 2019, the Company completed the acquisition of a 271,988 square foot office property located in Iselin, New Jersey, for a purchase price of $61.5 million, which was funded using funds available with the Company’s qualified intermediary and borrowings under the Company’s unsecured revolving credit facility.  On January 25, 2019, the Company signed an agreement to acquire a 377 -unit multi-family rental property located in Jersey City, New Jersey for approximately $264 million, subject to certain conditions. The acquisition is expected to be completed in the second quarter 2019.  2017 The Company acquired the following office properties (which were determined to be asset acquisitions in accordance with ASU 2017-01) during the year ended December 31, 2017 (dollars in thousands) :     Acquisition # of Rentable Acquisition  Date Property Address Location Bldgs. Square Feet Cost  01/11/17 Red Bank portfolio (a) Red Bank, New Jersey 3 279,472 $ 27,228  03/06/17 Short Hills/Madison portfolio (b) Short Hills & Madison, New Jersey 6 1,113,028 367,361   Total Acquisitions 9 1,392,500 $ 394,589   (a) This acquisition was funded through borrowings under the Company's unsecured revolving credit facility.  (b) This acquisition was funded through borrowings under the Company’s unsecured revolving credit facility and a new $124.5 million loan secured by three of the properties.  The purchase prices were allocated to the net assets acquired, as follows (in thousands) :     Red Bank Short Hills/Madison  Portfolio Portfolio Total  Land and leasehold interest $ 7,914 $ 30,336 $ 38,250  Buildings and improvements and other assets 16,047 295,299 311,346  Above market leases (a) 118 6,367 6,485  In-place lease values (a) 3,171 45,604 48,775  27,250 377,606 404,856  Less: Below market lease values (a) (22) (10,245) (10,267)  Net assets recorded upon acquisition $ 27,228 $ 367,361 $ 394,589  (a) Above market, in-place and below market leases are being amortized over a weighted-average term of 5.4 years.  The Company acquired three separate developable land parcels located in Jersey City, Morris Township and Red Bank, New Jersey, for approximately $80 million during the year ended December 31, 2017. The acquisitions were funded using available cash and borrowings under the Company’s unsecured revolving credit facility.  Properties Commencing Initial Operations The following properties commenced initial operations during the year ended December 31, 2018 ( dollars in thousands ):     # of Total  In-Service Apartment Units/ Development  Date Property Location Type Rooms Costs Incurred  03/01/18 145 Front at City Square Worcester, MA Multi-Family 365 $ 97,483 (a)  04/01/18 Signature Place at Morris Plains Morris Plains, NJ Multi-Family 197 56,715 (b)  05/01/18 Portside 5/6 East Boston, MA Multi-Family 296 114,694 (c)  08/01/18 RiverHouse 11 at Port Imperial Weehawken, NJ Multi-Family 295 130,369 (d)  12/13/18 Residence Inn By Marriott (Phase I) Weehawken, NJ Hotel 164 58,723 (e)  Totals 1,317 $ 457,984 (a) Development costs as of December 31, 2018 included approximately $4.4 in land costs. As of December 31, 2018, the Company anticipates additional costs of approximately $1.1 million, which will be primarily funded from a construction loan. (b) Development costs as of December 31, 2018 included approximately $0.9 in land costs. (c) As of December 31, 2018 , the Company anticipates additional costs of approximately $0.7 million, which will be funded by the Company. (d) As of December 31, 2018 , the Company anticipates additional costs of $1.2 million which will be funded by the Company. (e) As of December 31, 2018, the Company anticipates additional costs of $20.1 million which will be funded from a construction loan.  Consolidations 2018 On August 2, 2018, the Company, which held a 24.27 percent subordinated interest in the unconsolidated joint venture Marbella Tower Urban Renewal Associates LLC, a 412 -unit multi-family operating property located in Jersey City, New Jersey, acquired its equity partner’s 50 percent interest for $65.6 million in cash. The property was subject to a mortgage loan that had a principal balance of $95 million. The cash portion of the acquisition was funded primarily through borrowings under the Company's unsecured revolving credit facility. Concurrently with the closing, the joint venture repaid the $95 million mortgage loan in full and obtained a new loan from a different lender, collateralized by the property in the amount of $131 million, which bears interest at 4.07 percent and matures in August 2026 . The venture distributed $37.4 million of the loan proceeds, of which the Company’s share was $30.4 million. As a result of the acquisition, the Company increased its ownership of the property from a 24.27 percent subordinated interest to a 74.27 percent controlling interest. In accordance with ASC 810, Consolidation, the Company evaluated the acquisition and determined that the entity meets the criteria of a VIE. As such, the Company consolidated the asset upon acquisition and accordingly, remeasured its equity interests, as required by the FASB's consolidation guidance, at fair value (based upon the income approach using current rates and market cap rates and discount rates). As a result, the Company recorded a gain on change of control of interests of $14.2 million (a non-cash item) in the year ended December 31, 2018 , when the Company accounted for the transaction as a VIE that is not a business in accordance with ASC 810-10-30-4. Additional non-cash items included in the acquisition were the Company’s carrying value of its interest in the joint venture of $14 million and the noncontrolling interest’s fair value of $29.8 million (non-cash allocation). See Note 9: Mortgages, Loans Payable and Other Obligations.  Net assets recorded upon consolidation were as follows (in thousands) :     Land and leasehold interest $ 48,820  Buildings and improvements and other assets, net 162,958  In-place lease values (a) 6,947  Less: Below market lease values (a) (108)  218,617  Less: Debt (131,000)  Net Assets 87,617  Less: Noncontrolling interest (b) (22,812)  Net assets recorded upon consolidation $ 64,805   (a) In-place and below market leases are being amortized over a weighted-average term of 9.3 months.  (b) Noncontrolling interest balance reflects distribution of $7.0 million of loan proceeds at closing.  2017 On February 3, 2017, the Operating Partnership issued 42,800 shares of a new class of 3.5 percent Series A Preferred Limited Partnership Units of the Operating Partnership (the “Series A Units”) valued at $42.8 million. The Series A Units were issued to the Company’s partners in the Plaza VIII & IX Associates L.L.C. joint venture that owns a development site adjacent to the Company’s Harborside property in Jersey City, New Jersey as non-cash consideration for their approximate 37.5 percent interest in the joint venture. Concurrent with the issuance of the Series A Units, the Company purchased from other partners in the Plaza VIII & IX Associates L.L.C. joint venture their approximate 12.5 percent interest for approximately $14.3 million in cash. The results of these transactions increased the Company’s interests in the joint venture from 50 percent to 100 percent. Upon these acquisitions, the Company consolidated Plaza VIII & IX Associates L.L.C., a voting interest entity, substantially all of which is comprised of land for development. As an acquisition of the additional 50 percent of the land, the Company accounted for the transaction as an asset acquisition under a cost accumulation model, resulting in total consolidated assets of $60.6 million, substantially all of which is classified as land on the Balance Sheet.  On February 28, 2017, the Operating Partnership authorized the issuance of 9,213 shares of a new class of 3.5 percent Series A-1 Preferred Limited Partnership Units of the Operating Partnership (the “Series A-1 Units”). 9,122 Series A-1 Units were issued on February 28, 2017, valued at $9.1 million, to the Company’s partner in a joint venture with the Operating Partnership, which owns Monaco Towers in Jersey City, New Jersey that includes 523 apartment homes in two fifty -story towers with 558 parking spaces and 12,300 square feet of ground floor retail space. The Series A-1 Units were issued as non-cash consideration for the partner’s approximate 13.8 percent ownership interest in the joint venture to increase the Company’s unconsolidated investment to 29 percent. In April 2017, an additional 91 Series A-1 Units were issued by the Operating Partnership to purchase from other partners in the same joint venture their approximate 71.2 percent ownership interest for approximately $130.9 million in cash and $171.2 million in assumed debt in transactions which closed in April 2017. The results of these transactions increased the Company’s interests in the joint venture to 100 percent. Upon these acquisitions, the Company consolidated RoseGarden Monaco Holdings, L.L.C., a voting interest entity.  As an acquisition of the remaining interests in the venture which owns the Monaco Towers, the Company accounted for the transaction as an asset acquisition under a cost accumulation model, resulting in total consolidated net assets of $139.9 million which is allocated, as follows (in thousands):     Monaco Monaco  North South Total  Land and leasehold interest $ 27,300 $ 31,461 $ 58,761  Buildings and improvements and other assets 112,841 129,895 242,736  Above market leases (a) 350 - 350  In-place lease values (a) 4,585 4,913 9,498  Less: Below market lease values (a) (141) (118) (259)  144,935 166,151 311,086  Less: Debt assumed at fair value (79,544) (91,656) (171,200)  Net assets recorded upon consolidation $ 65,391 $ 74,495 $ 139,886  (a) Above market, in-place and below market leases are being amortized over a weighted-average term of 8 months .  Dispositions/Rental Property Held for Sale  2018 The Company disposed of the following office properties during the year ended December 31, 2018 (dollars in thousands) :     Realized  Gains  Rentable Net Net (losses)/  Disposition # of Square Sales Carrying Unrealized  Date Property/Address Location Bldgs. Feet Proceeds Value Losses, net  02/15/18 35 Waterview Boulevard (a) Parsippany, New Jersey 1 172,498 $ 25,994 $ 25,739 $ 255  03/05/18 Hamilton portfolio (b) Hamilton, New Jersey 6 239,262 17,546 17,501 45  03/07/18 Wall portfolio first closing Wall, New Jersey 5 179,601 14,053 10,526 3,527  03/22/18 700 Horizon Drive Hamilton, New Jersey 1 120,000 33,020 16,053 16,967  03/23/18 Wall portfolio second closing Wall, New Jersey 3 217,822 30,209 12,961 17,248  03/28/18 75 Livingston Avenue Roseland, New Jersey 1 94,221 7,983 5,609 2,374  03/28/18 20 Waterview Boulevard (c) Parsippany, New Jersey 1 225,550 12,475 11,795 680  03/30/18 Westchester Financial Center (d) White Plains, New York 2 489,000 81,769 64,679 17,090  06/27/18 65 Jackson Drive Cranford, New Jersey 0 - 1,510 (e) - 1,510  08/02/18 600 Horizon Drive Hamilton, New Jersey 1 95,000 15,127 6,191 8,936  09/05/18 1 & 3 Barker Avenue White Plains, New York 2 133,300 15,140 13,543 1,597  11/15/18 120 Passaic Street (f) Rochelle Park, New Jersey 1 52,000 2,667 2,568 99  12/31/18 Elmsford Distribution Center Elmsford, New York 6 387,400 66,557 17,314 49,243  Sub-total 30 2,405,654 324,050 204,479 119,571   Unrealized losses on rental property held for sale (20,135)  Totals 30 2,405,654 $ 324,050 $ 204,479 $ 99,436   (a) The Company recorded a valuation allowance of $0.7 million on this property during the year ended December 31, 2017.  (b) The Company recorded a valuation allowance of $0.6 million on these properties during the year ended December 31, 2017. The disposition additionally included two land properties.  (c) The Company recorded a valuation allowance of $11 million on this property during the year ended December 31, 2017. Prior to closing, the Company provided short term financing through a note receivable  to an affiliate of the buyers of $2.8 million. The note was paid off in the second quarter of 2018.  (d) Prior to closing, the Company provided financing through a note receivable to an affiliate of the buyers of $4.0 million. The note was paid off in October 2018.  (e) Represents the receipt by the Company in the second quarter 2018 of variable contingent sales consideration, net of costs, of $1.5 million subsequent to disposition of the property sold in January 2017.  (f) The net sale proceeds were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2018. See Note 5: Deferred Charges,  Goodwill and Other Assets, Net).  The Company disposed of the following developable land holding during the year ended December 31, 2018 (dollars in thousands) :     Net Net Gain on  Disposition Sales Carrying Disposition of  Date Property Address Location Proceeds Value Developable Land  12/31/18 One Lake Street Upper Saddle River, New Jersey (a) $ 46,036 $ 15,097 $ 30,939   Totals $ 46,036 $ 15,097 $ 30,939   (a) The net sale proceeds were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2018. See Note 5: Deferred  Charges, Goodwill and Other Assets, Net. The net carrying value includes $3 million of development costs funded at the closing.  The Company identified as held for sale six office properties, totaling approximately 845,000 square feet, and a 159 unit multi-family rental property as of December 31, 2018 . The properties are located in Fort Lee, Newark, Paramus, Bridgewater, Morris Plains and Rahway, New Jersey. The total estimated sales proceeds, net of expected selling costs, from the sales are expected to be approximately $124 million. The Company determined that the carrying value of four of the properties was not expected to be recovered from estimated net sales proceeds and accordingly recognized an unrealized loss allowance of $20.1 million for the year ended December 31, 2018 . In January 2019, the Company completed the disposition of three of these properties for sales proceeds of approximately $54.5 million.  The following table summarizes the rental property held for sale, net, as of December 31, 2018 (dollars in thousands):     December 31,  2018  Land $ 24,376  Buildings and improvements 159,857  Less: Accumulated depreciation (55,250)  Less: Unrealized losses on properties held for sale (20,135)  Rental property held for sale, net $ 108,848  Other assets and liabilities related to the rental properties held for sale, as of December 31, 2018, include $2.9 million in Deferred charges and other assets, $1.7 million in Unbilled rents receivable and $ 2.3 million in Accounts payable, accrued expenses and other liabilities. Approximately $3.9 million of these assets and $ 1.7 million of these liabilities are expected to be removed with the completion of the sales.  2017 The Company disposed of the following office properties during the year ended December 31, 2017 (dollars in thousands) :     Realized  Gains  Rentable Net Net (losses)/  Disposition # of Square Sales Carrying Unrealized  Date Property/Address Location Bldgs. Feet Proceeds Value Losses, net  01/30/17 Cranford portfolio Cranford, New Jersey 6 435,976 $ 26,598 $ 22,736 $ 3,862  01/31/17 440 Route 22 East (a) Bridgewater, New Jersey 1 198,376 10,074 10,069 5  02/07/17 3 Independence Way Princeton, New Jersey 1 111,300 11,549 9,910 1,639  05/15/17 103 Carnegie Center Princeton, New Jersey 1 96,000 15,063 8,271 6,792  08/29/17 400 Chestnut Ridge Road Woodcliff Lake, New Jersey 1 89,200 6,891 7,498 (607)  08/30/17 140 E. Ridgewood Avenue Paramus, New Jersey 1 239,680 30,201 30,737 (536)  08/30/17 Bergen portfolio Woodcliff Lake, Paramus and 5 1,061,544 86,973 (c) 135,121 (48,148)  Rochelle Park, New Jersey  09/11/17 377 Summerhill Road East Brunswick, New Jersey 1 40,000 3,221 2,172 1,049  09/13/17 700 Executive Boulevard Elmsford, New York - - (b) 5,717 970 4,747  09/20/17 Totowa Portfolio Totowa, New Jersey 13 499,243 63,624 27,630 35,994  09/27/17 890 Mountain Avenue (d) New Providence, New Jersey 1 80,000 4,852 6,139 (1,287)  09/28/17 135 Chestnut Ridge Road Montvale, New Jersey 1 66,150 5,844 (e) 2,929 2,915  09/29/17 Moorestown portfolio Moorestown and Burlington, New Jersey 26 1,260,398 73,393 (f) 56,186 17,207  10/19/17 1 Enterprise Boulevard Yonkers, New York - - (b) 3,230 1,380 1,850  11/15/17 61 South Paramus Road Paramus, New Jersey 1 269,191 23,255 37,184 (13,929)  12/06/17 300 Tice Boulevard Woodcliff Lake, New Jersey 1 230,000 28,847 25,705 3,142  Sub-total 60 4,677,058 399,332 384,637 14,695   Unrealized losses on rental property held for sale (12,331)   Totals 60 4,677,058 $ 399,332 $ 384,637 $ 2,364   (a) The Company recorded a valuation allowance of $7.7 million on this property during the year ended December 31, 2016.  (b) This disposition is of a ground leased land property.  (c) At closing, the Company provided short term seller financing aggregating $65 million through mortgage notes receivable to the buyers. These notes were paid off in November  and December 2017.  (d) The Company recorded an impairment charge of $7.0 million on this property during the year ended December 31, 2015.  (e) The Company recorded an impairment charge of $4.2 million on this property during the year ended December 31, 2015. $5.9 million of the sales proceeds from this sale were  held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2017. The Company received these proceeds in  March 2018. See Note 5: Deferred Charges, Goodwill and Other Assets, Net.  (f) $15.3 million of the sales proceeds from this sale were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets  as of December 31, 2017. The Company received these proceeds in March 2018. See Note 5: Deferred Charges, Goodwill and Other Assets, Net.  The Company identified as held for sale 21 office properties totaling approximately 2 million square feet as of December 31, 2017. The properties are located in Parsippany, Paramus, Rochelle Park, Hamilton and Wall, New Jersey and White Plains, New York. The total estimated sales proceeds from the sales were expected to be approximately $223 million. The Company determined that the carrying value of seven of the office properties was not expected to be recovered from estimated net sales proceeds and accordingly recognized an unrealized loss allowance of $12.3 million during the year ended December 31, 2017.  The following table summarizes the rental property held for sale, net, as of December 31, 2017 (dollars in thousands):     December 31,  2017  Land $ 37,024  Buildings and improvements 273,388  Less: Accumulated depreciation (126,503)  Less: Unrealized losses on properties held for sale (12,331)  Rental property held for sale,net $ 171,578   Other assets and liabilities related to the rental properties held for sale, as of December 31, 2017, included $9.8 million in deferred charges, and other assets, $4.7 million in Unbilled rents receivable and $ 4.6 million in Accounts payable, accrued expenses and other liabilities. Approximately $13.4 million of these assets and $ 0.3 million of these liabilities were expected to be written off with the completion of the sales.  Land Impairments The Company owns two separate developable land parcels in Conshohocken and Bala Cynwyd, Pennsylvania, that were being considered for development into multi-family rental properties. During the fourth quarter 2018, the Company made the decision to pursue selling the land parcels as opposed to development. Due to the shortening of the expected periods of ownership, the Company determined that it was necessary to reduce the carrying values of the land parcels to their estimated fair values (ascertained by broker opinions of value obtained during the marketing process) and recorded total land impairments charges of $24.6 million at December 31, 2018.  Rockpoint Transaction On February 27, 2017, the Company, RRT, the Company’s wholly-owned subsidiary through which the Company conducts its multi-family residential real estate operations, Roseland Residential, L.P. (“RRLP”), the operating partnership through which RRT conducts all of its operations, and certain other affiliates of the Company entered into an equity investment agreement (the “Investment Agreement”) with Rockpoint Group, L.L.C. and certain of its affiliates (collectively, “Rockpoint”). The Investment Agreement provides for multiple equity investments by Rockpoint in RRLP from time to time for up to an aggregate of $300 million of equity units of limited partnership interests of RRLP (the “Rockpoint Units”). The initial closing under the Investment Agreement occurred on March 10, 2017 for $150 million of Rockpoint Units. Additional closings of Rockpoint Units to be issued and sold to Rockpoint pursuant to the Investment Agreement may occur from time to time in increments of not less than $10 million per closing, with the balance of the full $300 million by March 1, 2019. See Note 14: Redeemable Noncontrolling Interests.  RRLP has been identified as a variable interest entity in which the Company is deemed to be the primary beneficiary. As of December 31, 2018 and December 31, 2017, the Company’s consolidated RRLP entity had total assets of $2.3 billion and $1.9 billion, respectively, total mortgages and loan payable of $1.1 billion and $769.7 million, respectively, and other liabilities of $57 million and $95.9 million, respectively.  Unconsolidated Joint Venture Activity On January 31, 2019, the Company, which held a 24.27 percent subordinated interest in the unconsolidated joint venture Marbella Tower Urban Renewal Associates South LLC, a 311-unit multi-family operating property located in Jersey City, New Jersey, acquired its equity partner’s 50 percent interest for $77.5 million in cash. The acquisition was funded primarily using available cash. Concurrently with the closing, the joint venture repaid in full the property’s $74.7 million mortgage loan and obtained a new loan in the amount of $117 million.  On December 11, 2018, the Company acquired one of its partner’s interest in the Metropolitan and Shops at 40 Park and the Lofts at 40 Park for $1.3 million and as a result, increased its ownership from 12.5 percent interest to 25 percent interest in the Metropolitan and Shops at 40 Park and from 25 percent interest to 50 percent interest in the Lofts at 40 Park.  On September 29, 2017, the Company sold its interests in the KPG-MCG Curtis joint venture that owns an operating property located in Philadelphia, Pennsylvania for a sales price of $102.5 million, which included the retirement of the Company’s share in a mortgage payable of $75 million, and realized a gain on the sale of the unconsolidated joint venture of $12 million. $5.6 million of the net sales proceeds from this sale were held by a qualified intermediary, which is considered non cash and recorded in deferred charges, goodwill and other assets. See Note 5: Deferred Charges, Goodwill and Other Assets, Net.   On September 21, 2017, the RoseGarden Monaco, L.L.C. joint venture agreement was terminated. Accordingly, the Company wrote off the carrying value of its investment in the joint venture and recorded a loss of $1.4 million on the disposition of its joint venture interest.  On February 15, 2017, the Company sold its 7.5 percent interest in the Elmajo Urban Renewal Associates, LLC and Estuary Urban Renewal Unit B, LLC joint ventures that own operating multi-family properties located in Weehawken, New Jersey for a sales price of $5.1 million and realized a gain on the sale of the unconsolidated joint venture of $5.1 million.  On January 31, 2017, the Company sold its interest in the KPG-P 100 IMW JV, LLC, Keystone-Penn and Keystone-Tristate joint ventures that own operating properties, located in Philadelphia, Pennsylvania for an aggregate sales price of $9.7 million and realized a gain on the sale of the unconsolidated joint venture of $7.4 million.

Investments In Unconsolidated J

Investments In Unconsolidated Joint Ventures	12 Months Ended
	Dec. 31, 2018
Investments In Unconsolidated Joint Ventures [Line Items]
Investments In Unconsolidated Joint Ventures	4. INVESTMENTS IN UNCONSOLIDATED JOINT VENTURES  As of December 31, 2018 , the Company had an aggregate investment of approximately $232.8 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 December 31, 2018 , the unconsolidated joint ventures owned: four office properties aggregating approximately 0.5 million square feet, eight multi-family properties totaling 2,922 apartment units, two retail properties aggregating approximately 81,700 square feet, a 350 -room hotel, a development project for up to approximately 360 apartment units; and interests and/or rights to developable land parcels able to accommodate up to 3,738 apartment units. The Company’s unconsolidated interests range from 20 percent to 85 percent subject to specified priority allocations in certain of the 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 December 31, 2018 , such debt had a total facility amount of $316.9 million of which the Company agreed to guarantee up to $35.8 million. As of December 31, 2018 , the outstanding balance of such debt totaled $204.9 million of which $24.6 million was guaranteed by the Company. The Company performed management, leasing, development and other services for the properties owned by the unconsolidated joint ventures and recognized $2.4 million and $2.8 million for such services in the years ended December 31, 2018 and 2017 , respectively. The Company had $ 0.2 million and $0.8 million in accounts receivable due from its unconsolidated joint ventures as of December 31, 2018 and 2017 .  Included in the Company’s investments in unconsolidated joint ventures as of December 31, 2018 are four 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 $ 129.5 million as of December 31, 2018 . The Company’s maximum exposure to loss as a result of its involvement with these VIEs is estimated to be approximately $ 165.4 million, which includes the Company’s current investment and estimated future funding commitments/guarantees of approximately $ 35.8 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 parties 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 December 31, 2018 and 2017 (dollars in thousands):    Property Debt  Number of Company's Carrying Value As of December 31, 2018  Apartment Units Effective December 31, December 31, Maturity Interest  Entity / Property Name or Rentable Square Feet (sf) Ownership % (a) 2018 2017 Balance Date Rate  Multi-family  Marbella (b) 412 units 24.27 % $ - $ 14,544 $ - - - %  Metropolitan at 40 Park (c) (d) 130 units 25.00 % 7,679 6,834 55,227 (e) (e)  RiverTrace at Port Imperial 316 units 22.50 % 8,112 8,864 82,000 11/10/26 3.21 %  Crystal House (f) 825 units 25.00 % 29,570 30,570 162,838 04/01/20 3.17 %  PI North - Riverwalk C 360 units 40.00 % 27,175 16,844 - 12/06/21 L+2.75 % (g)  Marbella II (i) 311 units 24.27 % 15,414 16,471 74,690 03/30/19 L+2.25 % (h)  Riverpark at Harrison 141 units 45.00 % 1,272 1,604 29,819 08/01/25 3.70 %  Station House 378 units 50.00 % 37,675 40,124 98,504 07/01/33 4.82 %  Urby at Harborside 762 units 85.00 % 85,317 94,429 191,732 08/01/29 5.197 % (j)  PI North -Land (k) 836 potential units 20.00 % 1,678 1,678 - - -  Liberty Landing 850 potential units 50.00 % 337 337 - - -  Hillsborough 206 160,000 sf 50.00 % 1,962 1,962 - - -   Office  Red Bank 92,878 sf 50.00 % 3,127 4,602 14,000 08/01/23 L+2.25 % (l)  12 Vreeland Road 139,750 sf 50.00 % 7,019 6,734 7,904 07/01/23 2.87 %  Offices at Crystal Lake 106,345 sf 31.25 % 3,442 3,369 4,076 11/01/23 4.76 %   Other  Riverwalk Retail 30,745 sf 20.00 % 1,539 1,625 - - -  Hyatt Regency Jersey City 351 rooms 50.00 % 112 440 100,000 10/01/26 3.668 %  Other (m) 1,320 1,595 - - -  Totals: $ 232,750 $ 252,626 $ 820,790    (a) Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.  (b) On August 2, 2018, the Company acquired its equity partner's 50 percent controlling interest in the venture and, as a result, increased its ownership from a 24.27 percent subordinated interest to 74.27 percent controlling interest. See Note 3: Recent Transactions - Consolidation.  (c) 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.  (d) 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 59 -unit, five story multi-family rental development property ("Lofts at 40 Park"). On December 11, 2018, the Company acquired one of its partner’s interest and as a result, increased its ownership from 12.5 percent interest to 25 percent interest in the Metropolitan and Shops at 40 Park and from 25 percent interest to 50 percent interest in the Lofts at 40 Park.  (e) Property debt balance consists of: (i) an amortizable loan, collateralized by the Metropolitan at 40 Park, with a balance of $36.0 million bears interest at 3.25 percent, matures in September 2020 ; (ii) an interest only loan, collateralized by the Shops at 40 Park, with a balance of $6.1 million, bears interest at LIBOR +2.25 percent, matures in September 2019 ; (iii) a loan with a maximum borrowing amount of $13,950 for the Lofts at 40 Park with a balance of $13.1 million, which bears interest at LIBOR plus 250 basis points and matures in February 2020 .  (f) Included in this is the Company's unconsolidated 50 percent interest in a vacant land to accommodate the development of approximately 295 additional units of which 252 are currently approved.  (g) The venture has a construction loan with a maximum borrowing amount of $112,000 .  (h) The construction loan which had a maximum borrowing amount of $75,000 was amended on 3/30/18 and, subject to certain conditions, provided for four 3 -month extension options with a fee of 6.25 basis points for each extension.  (i) On January 31, 2019, the Company, which held a 24.27 percent subordinated interest in the unconsolidated joint venture, Marbella Tower Urban Renewal Associates South LLC, a 311-unit multi-family operating property located in Jersey City, New Jersey, acquired the majority equity partner’s 50 percent interest in the venture for $77.5 million in cash. The cash portion of the acquisition was funded primarily through borrowings under the Company’s unsecured revolving credit facility. Concurrently with the closing, the joint venture repaid in full the property’s $74.7 million mortgage loan and obtained a new loan in the amount of $117 million.  (j) The construction/permanent loan has a maximum borrowing amount of $192 million. The Company owns an 85 percent interest with shared control over major decisions such as, approval of budgets, property financings and leasing guidelines.  (k) The Company also owns a 20 percent residual interest in undeveloped land parcels: parcels 6, I, and J that can accommodate the development of 836 apartment units.  (l) On August 1, 2018, the venture refinanced its mortgage loan with a maximum borrowing amount of $16,500 , bears interest at LIBOR +2.25% , matures on August 1, 2023 and subject to certain conditions, provided for two extension options.  (m) 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 years ended December 31, 2018 , 2017 and 2016 (dollars in thousands) :     Year Ended December 31,  Entity / Property Name 2018 2017 2016  Multi-family  Marbella (b) $ 205 $ 334 $ 231  Metropolitan at 40 Park (455) (311) (317)  RiverTrace at Port Imperial 154 196 (1,146)  Crystal House (874) (923) (870)  PI North - Pier Land (126) (219) (62)  PI North - Riverwalk C - (653) (58)  Marbella II 35 93 (202)  Riverpark at Harrison (232) (252) (190)  Station House (2,096) (1,793) (2,440)  Urby at Harborside (975) (c) (6,356) (219)  Liberty Landing (5) (15) (80)  Hillsborough 206 16 (25) (53)  Office  Red Bank (215) 238 448  12 Vreeland Road 285 496 347  Offices at Crystal Lake 73 89 (15)  Other  Roseland/North Retail, L.L.C./ Riverwalk at Port Imperial (86) (81) (52)  South Pier at Harborside / Hyatt Regency Jersey City on the Hudson 3,672 3,277 24,180  Other 497 (176) (714)  Company's equity in earnings (loss) of unconsolidated joint ventures (a) $ (127) $ (6,081) $ 18,788 (a) Amounts are net of amortization of basis differences of $903 , $792 and $436 for the years ended December 31, 2018 , 2017 and 2016 , respectively. (b) On August 2, 2018, the Company acquired one of its equity partner's 50 percent interest and as a result, increased its ownership from 24.27 percent subordinated interest to 74.27 percent controlling interest , and ceased applying the equity method of accounting at such time. (c) Includes $2.6 million of the Company's share of the venture's income from its first annual sale of an economic tax credit certificate from the State of New Jersey to a third party. The venture has an agreement with a third party to sell it the tax credits over the next nine years for $3 million per year for a total of $27 million. The sales are subject to the venture obtaining the tax credits from the State of New Jersey and transferring the credit certificates each year.  The following is a summary of the combined financial position of the unconsolidated joint ventures in which the Company had investment interests as of December 31, 2018 and 2017 (dollars in thousands and unaudited) :     December 31, December 31,  2018 2017  Assets:  Rental property, net $ 903,253 $ 931,419  Other assets 212,205 207,903  Total assets $ 1,115,458 $ 1,139,322  Liabilities and partners'/  members' capital:  Mortgages and loans payable $ 686,797 $ 689,412  Other liabilities 67,072 80,746  Partners'/members' capital 361,589 369,164  Total liabilities and  partners'/members' capital $ 1,115,458 $ 1,139,322   The following is a summary of the combined results from operations of the unconsolidated joint ventures for the period in which the Company had investment interests during the year s ended December 31, 2018 , 2017 and 2016 (dollars in thousands and unaudited) :    Year Ended December 31,  2018 2017 2016  Total revenues $ 310,919 $ 358,751 $ 377,711  Operating and other expenses (230,863) (297,492) (262,703)  Depreciation and amortization (40,193) (31,020) (75,512)  Interest expense (34,874) (25,822) (58,390)  Net income (loss) $ 4,989 $ 4,417 $ (18,894) 
Mack-Cali Realty LP [Member]
Investments In Unconsolidated Joint Ventures [Line Items]
Investments In Unconsolidated Joint Ventures	4. INVESTMENTS IN UNCONSOLIDATED JOINT VENTURES  As of December 31, 2018 , the Company had an aggregate investment of approximately $232.8 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 December 31, 2018 , the unconsolidated joint ventures owned: four office properties aggregating approximately 0.5 million square feet, eight multi-family properties totaling 2,922 apartment units, two retail properties aggregating approximately 81,700 square feet, a 350 -room hotel, a development project for up to approximately 360 apartment units; and interests and/or rights to developable land parcels able to accommodate up to 3,738 apartment units. The Company’s unconsolidated interests range from 20 percent to 85 percent subject to specified priority allocations in certain of the 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 December 31, 2018 , such debt had a total facility amount of $316.9 million of which the Company agreed to guarantee up to $35.8 million. As of December 31, 2018 , the outstanding balance of such debt totaled $204.9 million of which $24.6 million was guaranteed by the Company. The Company performed management, leasing, development and other services for the properties owned by the unconsolidated joint ventures and recognized $2.4 million and $2.8 million for such services in the years ended December 31, 2018 and 2017 , respectively. The Company had $ 0.2 million and $0.8 million in accounts receivable due from its unconsolidated joint ventures as of December 31, 2018 and 2017 .  Included in the Company’s investments in unconsolidated joint ventures as of December 31, 2018 are four 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 $ 129.5 million as of December 31, 2018 . The Company’s maximum exposure to loss as a result of its involvement with these VIEs is estimated to be approximately $ 165.4 million, which includes the Company’s current investment and estimated future funding commitments/guarantees of approximately $ 35.8 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 parties 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 December 31, 2018 and 2017 (dollars in thousands):    Property Debt  Number of Company's Carrying Value As of December 31, 2018  Apartment Units Effective December 31, December 31, Maturity Interest  Entity / Property Name or Rentable Square Feet (sf) Ownership % (a) 2018 2017 Balance Date Rate  Multi-family  Marbella (b) 412 units 24.27 % $ - $ 14,544 $ - - - %  Metropolitan at 40 Park (c) (d) 130 units 25.00 % 7,679 6,834 55,227 (e) (e)  RiverTrace at Port Imperial 316 units 22.50 % 8,112 8,864 82,000 11/10/26 3.21 %  Crystal House (f) 825 units 25.00 % 29,570 30,570 162,838 04/01/20 3.17 %  PI North - Riverwalk C 360 units 40.00 % 27,175 16,844 - 12/06/21 L+2.75 % (g)  Marbella II (i) 311 units 24.27 % 15,414 16,471 74,690 03/30/19 L+2.25 % (h)  Riverpark at Harrison 141 units 45.00 % 1,272 1,604 29,819 08/01/25 3.70 %  Station House 378 units 50.00 % 37,675 40,124 98,504 07/01/33 4.82 %  Urby at Harborside 762 units 85.00 % 85,317 94,429 191,732 08/01/29 5.197 % (j)  PI North -Land (k) 836 potential units 20.00 % 1,678 1,678 - - -  Liberty Landing 850 potential units 50.00 % 337 337 - - -  Hillsborough 206 160,000 sf 50.00 % 1,962 1,962 - - -   Office  Red Bank 92,878 sf 50.00 % 3,127 4,602 14,000 08/01/23 L+2.25 % (l)  12 Vreeland Road 139,750 sf 50.00 % 7,019 6,734 7,904 07/01/23 2.87 %  Offices at Crystal Lake 106,345 sf 31.25 % 3,442 3,369 4,076 11/01/23 4.76 %   Other  Riverwalk Retail 30,745 sf 20.00 % 1,539 1,625 - - -  Hyatt Regency Jersey City 351 rooms 50.00 % 112 440 100,000 10/01/26 3.668 %  Other (m) 1,320 1,595 - - -  Totals: $ 232,750 $ 252,626 $ 820,790    (a) Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.  (b) On August 2, 2018, the Company acquired its equity partner's 50 percent controlling interest in the venture and, as a result, increased its ownership from a 24.27 percent subordinated interest to 74.27 percent controlling interest. See Note 3: Recent Transactions - Consolidation.  (c) 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.  (d) 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 59 -unit, five story multi-family rental development property ("Lofts at 40 Park"). On December 11, 2018, the Company acquired one of its partner’s interest and as a result, increased its ownership from 12.5 percent interest to 25 percent interest in the Metropolitan and Shops at 40 Park and from 25 percent interest to 50 percent interest in the Lofts at 40 Park.  (e) Property debt balance consists of: (i) an amortizable loan, collateralized by the Metropolitan at 40 Park, with a balance of $36.0 million bears interest at 3.25 percent, matures in September 2020 ; (ii) an interest only loan, collateralized by the Shops at 40 Park, with a balance of $6.1 million, bears interest at LIBOR +2.25 percent, matures in September 2019 ; (iii) a loan with a maximum borrowing amount of $13,950 for the Lofts at 40 Park with a balance of $13.1 million, which bears interest at LIBOR plus 250 basis points and matures in February 2020 .  (f) Included in this is the Company's unconsolidated 50 percent interest in a vacant land to accommodate the development of approximately 295 additional units of which 252 are currently approved.  (g) The venture has a construction loan with a maximum borrowing amount of $112,000 .  (h) The construction loan which had a maximum borrowing amount of $75,000 was amended on 3/30/18 and, subject to certain conditions, provided for four 3 -month extension options with a fee of 6.25 basis points for each extension.  (i) On January 31, 2019, the Company, which held a 24.27 percent subordinated interest in the unconsolidated joint venture, Marbella Tower Urban Renewal Associates South LLC, a 311-unit multi-family operating property located in Jersey City, New Jersey, acquired the majority equity partner’s 50 percent interest in the venture for $77.5 million in cash. The cash portion of the acquisition was funded primarily through borrowings under the Company’s unsecured revolving credit facility. Concurrently with the closing, the joint venture repaid in full the property’s $74.7 million mortgage loan and obtained a new loan in the amount of $117 million.  (j) The construction/permanent loan has a maximum borrowing amount of $192 million. The Company owns an 85 percent interest with shared control over major decisions such as, approval of budgets, property financings and leasing guidelines.  (k) The Company also owns a 20 percent residual interest in undeveloped land parcels: parcels 6, I, and J that can accommodate the development of 836 apartment units.  (l) On August 1, 2018, the venture refinanced its mortgage loan with a maximum borrowing amount of $16,500 , bears interest at LIBOR +2.25% , matures on August 1, 2023 and subject to certain conditions, provided for two extension options.  (m) 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 years ended December 31, 2018 , 2017 and 2016 (dollars in thousands) :     Year Ended December 31,  Entity / Property Name 2018 2017 2016  Multi-family  Marbella (b) $ 205 $ 334 $ 231  Metropolitan at 40 Park (455) (311) (317)  RiverTrace at Port Imperial 154 196 (1,146)  Crystal House (874) (923) (870)  PI North - Pier Land (126) (219) (62)  PI North - Riverwalk C - (653) (58)  Marbella II 35 93 (202)  Riverpark at Harrison (232) (252) (190)  Station House (2,096) (1,793) (2,440)  Urby at Harborside (975) (c) (6,356) (219)  Liberty Landing (5) (15) (80)  Hillsborough 206 16 (25) (53)  Office  Red Bank (215) 238 448  12 Vreeland Road 285 496 347  Offices at Crystal Lake 73 89 (15)  Other  Roseland/North Retail, L.L.C./ Riverwalk at Port Imperial (86) (81) (52)  South Pier at Harborside / Hyatt Regency Jersey City on the Hudson 3,672 3,277 24,180  Other 497 (176) (714)  Company's equity in earnings (loss) of unconsolidated joint ventures (a) $ (127) $ (6,081) $ 18,788 (a) Amounts are net of amortization of basis differences of $903 , $792 and $436 for the years ended December 31, 2018 , 2017 and 2016 , respectively. (b) On August 2, 2018, the Company acquired one of its equity partner's 50 percent interest and as a result, increased its ownership from 24.27 percent subordinated interest to 74.27 percent controlling interest , and ceased applying the equity method of accounting at such time. (c) Includes $2.6 million of the Company's share of the venture's income from its first annual sale of an economic tax credit certificate from the State of New Jersey to a third party. The venture has an agreement with a third party to sell it the tax credits over the next nine years for $3 million per year for a total of $27 million. The sales are subject to the venture obtaining the tax credits from the State of New Jersey and transferring the credit certificates each year.  The following is a summary of the combined financial position of the unconsolidated joint ventures in which the Company had investment interests as of December 31, 2018 and 2017 (dollars in thousands and unaudited) :     December 31, December 31,  2018 2017  Assets:  Rental property, net $ 903,253 $ 931,419  Other assets 212,205 207,903  Total assets $ 1,115,458 $ 1,139,322  Liabilities and partners'/  members' capital:  Mortgages and loans payable $ 686,797 $ 689,412  Other liabilities 67,072 80,746  Partners'/members' capital 361,589 369,164  Total liabilities and  partners'/members' capital $ 1,115,458 $ 1,139,322   The following is a summary of the combined results from operations of the unconsolidated joint ventures for the period in which the Company had investment interests during the year s ended December 31, 2018 , 2017 and 2016 (dollars in thousands and unaudited) :    Year Ended December 31,  2018 2017 2016  Total revenues $ 310,919 $ 358,751 $ 377,711  Operating and other expenses (230,863) (297,492) (262,703)  Depreciation and amortization (40,193) (31,020) (75,512)  Interest expense (34,874) (25,822) (58,390)  Net income (loss) $ 4,989 $ 4,417 $ (18,894) 

Deferred Charges, Goodwill And

Deferred Charges, Goodwill And Other Assets, Net	12 Months Ended
	Dec. 31, 2018
Deferred Charges, Goodwill And Other Assets [Line Items]
Deferred Charges, Goodwill And Other Assets, Net	5. DEFERRED CHARGES, GOODWILL AND OTHER ASSETS, NET    December 31,  (dollars in thousands) 2018 2017  Deferred leasing costs $ 173,822 $ 199,515  Deferred financing costs - unsecured revolving credit facility (a) 5,356 4,945  179,178 204,460  Accumulated amortization (71,326) (98,956)  Deferred charges, net 107,852 105,504  Notes receivable (b) 47,409 50,167  In-place lease values, related intangibles and other assets, net (c) (d) 89,860 102,757  Goodwill (e) 2,945 2,945  Prepaid expenses and other assets, net (f) 107,168 80,947   Total deferred charges, goodwill and other assets, net $ 355,234 $ 342,320  (a) Deferred financing costs related to all other debt liabilities (other than for the unsecured revolving credit facility) are netted against those debt liabilities for all periods presented. See Note 2: Significant Accounting Policies – Deferred Financing Costs. (b) Includes as of December 31, 2018 and 2017, respectively, a mortgage receivable with a balance of $ 45.2 million and $45.7 million (acquired in August 2017) which bears interest at 5.85 percent and matures in July 2019 , with a three -month extension option and an interest-free note receivable with a net present value of $2.2 million and $2.5 million, which matures in April 2023 . The Company believes these balances are fully collectible. (c) In accordance with ASC 805, Business Combinations, the Company recognizes rental revenue of acquired above and below market lease intangibles over the terms of the respective leases. The impact of amortizing the acquired above and below-market lease intangibles increased revenue by approximately $ 5.3 million, $7.9 million and $1.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The following table summarizes, as of December 31, 2018 , the scheduled amortization of the Company’s acquired above and below-market lease intangibles for each of the five succeeding years (dollars in thousands) :     Acquired Above- Acquired Below-  Market Lease Market Lease Total  Year Intangibles Intangibles Amortization  2019 $ (2,559) $ 5,050 $ 2,491  2020 (2,377) 4,305 1,928  2021 (2,245) 4,186 1,941  2022 (2,132) 4,064 1,932  2023 (1,207) 3,279 2,072  (d) The value of acquired in-place lease intangibles are amortized to expense over the remaining initial terms of the respective leases. The impact of the amortization of acquired in-place lease values is included in depreciation and amortization expense and amounted to approximately $17.9 million, $32.2 million and $14.3 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The following table summarizes, as of December 31, 2018 , the scheduled amortization of the Company’s acquired in-place lease values for each of the five succeeding years (dollars in thousands) :    Year  2019 $ 10,494  2020 8,050  2021 6,884  2022 6,059  2023 4,943   (e) All goodwill is attributable to the Company’s Multi-family Real Estate and Services segment. (f) Includes as of December 31, 2018 and 2017, $49.2 million and $26.9 million, respectively, of proceeds from property sales held by a qualified intermediary.  DERIVATIVE FINANCIAL INSTRUMENTS  Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company primarily uses interest rate swaps as part of its interest rate risk management strategy. As of December 31, 2018 , the Company had outstanding interest rate swaps with a combined notional value of $675 million that were designated as cash flow hedges of interest rate risk. During the year ending December 31, 2018 , such derivatives were used to hedge the variable cash flows associated with existing variable-rate debt.  The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The ineffective portion of the change in fair value of the derivatives is recognized directly in earnings. During the years ended December 31, 2018 , 2017 and 2016 the Company recorded ineffectiveness gain (loss) of $ (0.2) million, $(37,000) and 0.6 million, respectively, which is included in interest and other investment income (loss) in the consolidated statements of operations, attributable to a floor mismatch in the underlying indices of the derivatives and the hedged interest payments made on its variable-rate debt. Amounts reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are made on the Company’s variable-rate debt. During the next 12 months, the Company estimates that an additional $ 6.7 million will be reclassified as a decrease to interest expense.  Undesignated Cash Flow Hedges of Interest Rate Risk Interest rate caps not designated as hedges are not speculative and are used to manage the Company’s exposure to interest rate movements but do not meet the strict hedge accounting requirements. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings. The Company recognized expenses of $2,000 for the year ended December 31, 2016 , which is included in interest and other investment income (loss) in the consolidated statements of operations.  The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Balance Sheet as of December 31, 2018 and 2017 (dollars in thousands) :     Fair Value  Asset Derivatives designated December 31,  as hedging instruments 2018 2017 Balance sheet location  Interest rate swaps $ 10,175 $ 8,060 Deferred charges, goodwill and other assets  The table below presents the effect of the Company’s derivative financial instruments on the Income Statement for the year s ending December 31, 2018 , 2017 and 2016 (dollars in thousands) :     Derivatives in Cash Flow Hedging Relationships Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion) Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion, Reclassification for Forecasted Transactions No Longer Probable of Occurring and Amount Excluded from Effectiveness Testing)  Year ended December 31, 2018 2017 2016 2018 2017 2016 2018 2017 2016   Interest rate swaps $ 5,262 $ 2,869 $ (1,183) Interest expense $ 2,944 $ (2,381) $ (3,398) Interest and other investment income (loss) $ (204) $ (37) $ 631  Credit-risk-related Contingent Features The Company has agreements with each of its derivative counterparties that contain a provision where the Company could be declared in default on its derivative obligations if repayment of the underlying indebtedness is accelerated by the lender due to the Company's default on the indebtedness. As of December 31, 2018 , the Company did not have derivatives in a net liability position including accrued interest but excluding any adjustment for nonperformance risk related to these agreements. As of December 31, 2018 , the Company has not posted any collateral related to these agreements.
Mack-Cali Realty LP [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Deferred Charges, Goodwill And Other Assets, Net	5. DEFERRED CHARGES, GOODWILL AND OTHER ASSETS, NET    December 31,  (dollars in thousands) 2018 2017  Deferred leasing costs $ 173,822 $ 199,515  Deferred financing costs - unsecured revolving credit facility (a) 5,356 4,945  179,178 204,460  Accumulated amortization (71,326) (98,956)  Deferred charges, net 107,852 105,504  Notes receivable (b) 47,409 50,167  In-place lease values, related intangibles and other assets, net (c) (d) 89,860 102,757  Goodwill (e) 2,945 2,945  Prepaid expenses and other assets, net (f) 107,168 80,947   Total deferred charges, goodwill and other assets, net $ 355,234 $ 342,320  (a) Deferred financing costs related to all other debt liabilities (other than for the unsecured revolving credit facility) are netted against those debt liabilities for all periods presented. See Note 2: Significant Accounting Policies – Deferred Financing Costs. (b) Includes as of December 31, 2018 and 2017, respectively, a mortgage receivable with a balance of $ 45.2 million and $45.7 million (acquired in August 2017) which bears interest at 5.85 percent and matures in July 2019 , with a three -month extension option and an interest-free note receivable with a net present value of $2.2 million and $2.5 million, which matures in April 2023 . The Company believes these balances are fully collectible. (c) In accordance with ASC 805, Business Combinations, the Company recognizes rental revenue of acquired above and below market lease intangibles over the terms of the respective leases. The impact of amortizing the acquired above and below-market lease intangibles increased revenue by approximately $ 5.3 million, $7.9 million and $1.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The following table summarizes, as of December 31, 2018 , the scheduled amortization of the Company’s acquired above and below-market lease intangibles for each of the five succeeding years (dollars in thousands) :     Acquired Above- Acquired Below-  Market Lease Market Lease Total  Year Intangibles Intangibles Amortization  2019 $ (2,559) $ 5,050 $ 2,491  2020 (2,377) 4,305 1,928  2021 (2,245) 4,186 1,941  2022 (2,132) 4,064 1,932  2023 (1,207) 3,279 2,072  (d) The value of acquired in-place lease intangibles are amortized to expense over the remaining initial terms of the respective leases. The impact of the amortization of acquired in-place lease values is included in depreciation and amortization expense and amounted to approximately $17.9 million, $32.2 million and $14.3 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The following table summarizes, as of December 31, 2018 , the scheduled amortization of the Company’s acquired in-place lease values for each of the five succeeding years (dollars in thousands) :    Year  2019 $ 10,494  2020 8,050  2021 6,884  2022 6,059  2023 4,943   (e) All goodwill is attributable to the Company’s Multi-family Real Estate and Services segment. (f) Includes as of December 31, 2018 and 2017, $49.2 million and $26.9 million, respectively, of proceeds from property sales held by a qualified intermediary.  DERIVATIVE FINANCIAL INSTRUMENTS  Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company primarily uses interest rate swaps as part of its interest rate risk management strategy. As of December 31, 2018 , the Company had outstanding interest rate swaps with a combined notional value of $675 million that were designated as cash flow hedges of interest rate risk. During the year ending December 31, 2018 , such derivatives were used to hedge the variable cash flows associated with existing variable-rate debt.  The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The ineffective portion of the change in fair value of the derivatives is recognized directly in earnings. During the years ended December 31, 2018 , 2017 and 2016 the Company recorded ineffectiveness gain (loss) of $ (0.2) million, $(37,000) and 0.6 million, respectively, which is included in interest and other investment income (loss) in the consolidated statements of operations, attributable to a floor mismatch in the underlying indices of the derivatives and the hedged interest payments made on its variable-rate debt. Amounts reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are made on the Company’s variable-rate debt. During the next 12 months, the Company estimates that an additional $ 6.7 million will be reclassified as a decrease to interest expense.  Undesignated Cash Flow Hedges of Interest Rate Risk Interest rate caps not designated as hedges are not speculative and are used to manage the Company’s exposure to interest rate movements but do not meet the strict hedge accounting requirements. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings. The Company recognized expenses of $2,000 for the year ended December 31, 2016 , which is included in interest and other investment income (loss) in the consolidated statements of operations.  The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Balance Sheet as of December 31, 2018 and 2017 (dollars in thousands) :     Fair Value  Asset Derivatives designated December 31,  as hedging instruments 2018 2017 Balance sheet location  Interest rate swaps $ 10,175 $ 8,060 Deferred charges, goodwill and other assets  The table below presents the effect of the Company’s derivative financial instruments on the Income Statement for the year s ending December 31, 2018 , 2017 and 2016 (dollars in thousands) :     Derivatives in Cash Flow Hedging Relationships Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion) Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion, Reclassification for Forecasted Transactions No Longer Probable of Occurring and Amount Excluded from Effectiveness Testing)  Year ended December 31, 2018 2017 2016 2018 2017 2016 2018 2017 2016   Interest rate swaps $ 5,262 $ 2,869 $ (1,183) Interest expense $ 2,944 $ (2,381) $ (3,398) Interest and other investment income (loss) $ (204) $ (37) $ 631  Credit-risk-related Contingent Features The Company has agreements with each of its derivative counterparties that contain a provision where the Company could be declared in default on its derivative obligations if repayment of the underlying indebtedness is accelerated by the lender due to the Company's default on the indebtedness. As of December 31, 2018 , the Company did not have derivatives in a net liability position including accrued interest but excluding any adjustment for nonperformance risk related to these agreements. As of December 31, 2018 , the Company has not posted any collateral related to these agreements.

Restricted Cash

Restricted Cash	12 Months Ended
	Dec. 31, 2018
Restricted Cash [Line Items]
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) :    December 31,  2018 2017  Security deposits $ 10,257 $ 9,446  Escrow and other reserve funds 9,664 30,346   Total restricted cash $ 19,921 $ 39,792 
Mack-Cali Realty LP [Member]
Restricted Cash [Line Items]
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) :    December 31,  2018 2017  Security deposits $ 10,257 $ 9,446  Escrow and other reserve funds 9,664 30,346   Total restricted cash $ 19,921 $ 39,792 

Senior Unsecured Notes

Senior Unsecured Notes	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Line Items]
Senior Unsecured Notes	7. SENIOR UNSECURED NOTES  A summary of the Company’s senior unsecured notes as of December 31, 2018 and 2017 is as follows (dollars in thousands) :     December 31, December 31, Effective  2018 2017 Rate (1)  4.500% Senior Unsecured Notes, due April 18, 2022 $ 300,000 $ 300,000 4.612 %  3.150% Senior Unsecured Notes, due May 15, 2023 275,000 275,000 3.517  Principal balance outstanding 575,000 575,000  Adjustment for unamortized debt discount (2,838) (3,505)  Unamortized deferred financing costs (1,848) (2,350)   Total senior unsecured notes, net $ 570,314 $ 569,145  (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 December 31, 2018 .
Mack-Cali Realty LP [Member]
Debt Disclosure [Line Items]
Senior Unsecured Notes	7. SENIOR UNSECURED NOTES  A summary of the Company’s senior unsecured notes as of December 31, 2018 and 2017 is as follows (dollars in thousands) :     December 31, December 31, Effective  2018 2017 Rate (1)  4.500% Senior Unsecured Notes, due April 18, 2022 $ 300,000 $ 300,000 4.612 %  3.150% Senior Unsecured Notes, due May 15, 2023 275,000 275,000 3.517  Principal balance outstanding 575,000 575,000  Adjustment for unamortized debt discount (2,838) (3,505)  Unamortized deferred financing costs (1,848) (2,350)   Total senior unsecured notes, net $ 570,314 $ 569,145  (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 December 31, 2018 .

Unsecured Revolving Credit Faci

Unsecured Revolving Credit Facility And Term Loans	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Line Items]
Unsecured Revolving Credit Facility And Term Loans	8. UNSECURED REVOLVING CREDIT FACILITY AND TERM LOANS  On January 25, 2017, the Company entered into an amended revolving credit facility and new term loan agreement (“2017 Credit Agreement”) with a group of 13 lenders. Pursuant to the 2017 Credit Agreement, the Company refinanced its existing $600 million unsecured revolving credit facility (“2017 Credit Facility”) and entered into a new $325 million unsecured, delayed draw term loan facility (“2017 Term Loan”). Effective March 6, 2018, the Company elected to determine its interest rate under the 2017 Credit Agreement and under the 2017 Term Loan using the defined leverage ratio option, resulting in an interest rate of LIBOR plus 130 basis points and LIBOR plus 155 basis points, respectively.  The terms of the 2017 Credit Facility include: (1) a four -year term ending in January 2021 , with two six -month extension options; (2) revolving credit loans may be made to the Company in an aggregate principal amount of up to $600 million (subject to increase as discussed below), with a sublimit under the 2017 Credit Facility for the issuance of letters of credit in an amount not to exceed $60 million (subject to increase as discussed below); (3) an interest rate, based on the Operating Partnership’s unsecured debt ratings from Moody’s or S&P, or, at the Operating Partnership’s option, if it no longer maintains a debt rating from Moody’s or S&P or such debt ratings fall below Baa3 and BBB-, based on a defined leverage ratio; and (4) a facility fee, currently 25 basis points, payable quarterly based on the Operating Partnership’s unsecured debt ratings from Moody’s or S&P, or, at the Operating Partnership’s option, if it no longer maintains a debt rating from Moody’s or S&P or such debt ratings fall below Baa3 and BBB-, based on a defined leverage ratio.  After electing to use the defined leverage ratio to determine the interest rate, the interest rates on outstanding borrowings, alternate base rate loans and the facility fee on the current borrowing capacity, payable quarterly in arrears, on the 2017 Credit Facility are currently based on the following total leverage ratio grid:    Interest Rate -  Applicable Basis Points  Interest Rate - Above LIBOR for  Applicable Basis Alternate Base Rate Facility Fee  Total Leverage Ratio Points above LIBOR Loans Basis Points  < 45% 125.0 25.0 20.0  ≥ 45% and <50% (current ratio) 130.0 30.0 25.0  ≥ 50% and <55% 135.0 35.0 30.0  ≥ 55% 160.0 60.0 35.0  Prior to the election to use the defined leverage ratio option, the interest rates on outstanding borrowings, alternate base rate loans and the facility fee on the current borrowing capacity, payable quarterly in arrears, on the 2017 Credit Facility were based upon the Operating Partnership’s unsecured debt ratings, as follows:     Interest Rate -  Applicable Basis Points  Operating Partnership's Interest Rate - Above LIBOR for  Unsecured Debt Ratings: Applicable Basis Points Alternate Base Rate Facility Fee  Higher of S&P or Moody's Above LIBOR Loans Basis Points  No ratings or less than BBB-/Baa3 155.0 55.0 30.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 120.0 20.0 25.0  BBB or Baa2 100.0 0.0 20.0  BBB+ or Baa1 90.0 0.0 15.0  A- or A3 or higher 87.5 0.0 12.5   The terms of the 2017 Term Loan include: (1) a three -year term ending in January 2020 , with two one -year extension options; (2) multiple draws of the term loan commitments may be made within 12 months of the effective date of the 2017 Credit Agreement up to an aggregate principal amount of $325 million (subject to increase as discussed below), with no requirement to be drawn in full; provided, that, if the Company does not borrow at least 50 percent of the initial term commitment from the term lenders (i.e. 50 percent of $325 million) on or before July 25, 2017, the amount of unused term loan commitments shall be reduced on such date so that, after giving effect to such reduction, the amount of unused term loan commitments is not greater than the outstanding term loans on such date; (3) a n interest rate based on the Operating Partnership’s unsecured debt ratings from Moody’s or S&P, or, at the Operating Partnership’s option if it no longer maintains a debt rating from Moody’s or S&P or such debt ratings fall below Baa3 and BBB-, based on a defined leverage ratio; and (4) a term commitment fee on any unused term loan commitment during the first 12 months after the effective date of the 2017 Credit Agreement at a rate of 0.25 percent per annum on the sum of the average daily unused portion of the aggregate term loan commitments.  On March 22, 2017, the Company drew the full $325 million available under the 2017 Term Loan. On March 29, 2017, the Company executed interest rate swap arrangements to fix LIBOR with an aggregate average rate of 1.6473% for the swaps and a current aggregate fixed rate of 3.1973% on borrowings under the 2017 Term Loan.  After electing to use the defined leverage ratio to determine the interest rate, the interest rate under the 2017 Term Loan is currently based on the following total leverage ratio grid:    Interest Rate -  Applicable Basis Points  Interest Rate - Above LIBOR for  Applicable Basis Alternate Base Rate  Total Leverage Ratio Points above LIBOR Loans  < 45% 145.0 45.0  ≥ 45% and < 50% (current ratio) 155.0 55.0  ≥ 50% and < 55% 165.0 65.0  ≥ 55% 195.0 95.0  Prior to the election to use the defined leverage ratio option, the interest rate on the 2017 Term Loan was based upon the Operating Partnership's unsecured debt ratings, as follows:     Interest Rate -  Applicable Basis Points  Operating Partnership's Interest Rate - Above LIBOR for  Unsecured Debt Ratings: Applicable Basis Points Alternate Base Rate  Higher of S&P or Moody's Above LIBOR Loans  No ratings or less than BBB-/Baa3 185.0 85.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 140.0 40.0  BBB or Baa2 115.0 15.0  BBB+ or Baa1 100.0 0.0  A- or A3 or higher 90.0 0.0   On up to four occasions at any time after the effective date of the 2017 Credit Agreement , the Company may elect to request (1) an increase to the existing revolving credit commitments (any such increase, the “New Revolving Credit Commitments”) and/or (2) the establishment of one or more new term loan commitments (the “New Term Commitments”, together with the 2017 Credit Commitments, the “Incremental Commitments”), by up to an aggregate amount not to exceed $350 million for all Incremental Commitments. The Company may also request that the sublimit for letters of credit available under the 2017 Credit Facility be increased to $100 million (without arranging any New Revolving Credit Commitments). No lender or letter of credit issued has any obligation to accept any Incremental Commitment or any increase to the letter of credit subfacility. There is no premium or penalty associated with full or partial prepayment of borrowings under the 2017 Credit Agreement. The 2017 Credit Agreement, which applies to both the 2017 Credit Facility and 2017 Term Loan, includes 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 2017 Credit Agreement (described below), or (ii) the property dispositions are completed while the Company is under an event of default under the 2017 Credit Agreement, 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 entire outstanding balance under the 2017 Credit Agreement may (or, in the case of any bankruptcy event of default, shall) become immediately due and payable, and the Company will not make any excess distributions except to enable the General Partner to continue to qualify as a REIT under the IRS Code.  Before it amended and restated its unsecured revolving credit facility in January 2017, the Company had a $600 million unsecured revolving credit facility with a group of 17 lenders that was scheduled to mature in July 2017. 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, was based upon the Operating Partnership’s unsecured debt ratings at the time, 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 (since January 2017 amendment) 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  In January 2016, the Company obtained a $350 million unsecured term loan (“2016 Term Loan”), which matures in January 2019 with two one ‑year extension options. On January 7, 2019, the Company exercised the first one -year extension option with the payment of an extension fee of $0.5 million, which extended the maturity of the 2016 Term Loan to January 2020 . The interest rate for the term loan is based on the Operating Partnership’s unsecured debt ratings, or, at the Company's option, a defined leverage ratio. Effective March 6, 2018, the Company elected to determine its interest rate under the 2016 Term Loan using the defined leverage ratio option, resulting in an interest rate of LIBOR plus 155 basis points. The Company entered into interest rate swap arrangements to fix LIBOR for the duration of the term loan. Including costs, the current all-in fixed rate is 3.28 percent. The proceeds from the loan were used primarily to repay outstanding borrowings on the Company’s then existing unsecured revolving credit facility and to repay $200 million senior unsecured notes that matured on January 15, 2016 .  After electing to use the defined leverage ratio to determine the interest rate, the interest rate under the 2016 Term Loan is currently based on the following total leverage ratio grid:    Interest Rate -  Applicable Basis  Total Leverage Ratio Points above LIBOR  < 45% 145.0  ≥ 45% and < 50% (current ratio) 155.0  ≥ 50% and < 55% 165.0  ≥ 55% 195.0  Prior to the election to use the defined interest leverage ratio option, the interest rate on the 2016 Term Loan was based upon the Operating Partnership’s unsecured debt ratings, as follows:    Operating Partnership's Interest Rate -  Unsecured Debt Ratings: Applicable Basis Points  Higher of S&P or Moody's Above LIBOR  No ratings or less than BBB-/Baa3 185.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 140.0  BBB or Baa2 115.0  BBB+ or Baa1 100.0  A- or A3 or higher 90.0  The terms of the 2016 Term Loan 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 term loan described below, or (ii) the property dispositions are completed while the Company is under an event of default under the term loan, 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 General Partner to continue to qualify as a REIT under the IRS Code.  On August 30, 2018, the Company entered into an amendment to the 2017 Credit Agreement (the “2017 Credit Agreement Amendment”) and an amendment to the 2016 Term Loan (the “2016 Term Loan Amendment”).  Each of the 2017 Credit Agreement Amendment and the 2016 Term Loan Amendment is effective as of June 30, 2018 and provides for the following material amendments to the terms of both the 2017 Credit Agreement and 2016 Term Loan):  1. The unsecured debt ratio covenant has been modified with respect to the measurement of the unencumbered collateral pool of assets in the calculation of such ratio for the period commencing July 1, 2018 and continuing until December 31, 2019 to allow the Operating Partnership to utilize the “as-is” appraised value of the properties known as ‘Harborside Plaza I’ and ‘Harborside Plaza V’ properties located in Jersey City, NJ in such calculation; and 2. A new covenant has been added that prohibits the Company from making any optional or voluntary payment, repayment, repurchase or redemption of any unsecured indebtedness of the Company (or any subsidiaries) that matures after January 25, 2022, at any time when any of the Total Leverage Ratio or the unsecured debt ratio covenants exceeds 60 percent (all as defined in the 2017 Credit Agreement and the 2016 Term Loan) or an appraisal is being used to determine the value of Harborside Plaza I and Harborside Plaza V for the unsecured debt ratio covenant.  All other terms and conditions of the 2017 Credit Agreement and the 2016 Term Loan remain unchanged.  The Company was in compliance with its debt covenants under its unsecured revolving credit facility and term loans as of December 31, 2018 .  As of December 31, 2018 and 2017 , the Company’s unsecured credit facility and term loans totaled $790.9 million and $822.3 million, respectively, comprised of: $117 million of outstanding borrowings under its unsecured revolving credit facility, $350.0 million from the 2016 Term Loan and $323.9 million from the 2017 Term Loan (net of unamortized deferred financing costs of $1.1 million) as of December 31, 2018 , and $150 million of outstanding borrowings under its unsecured revolving credit facility and $349.0 million from the 2016 Term Loan (net of unamortized deferred financing costs of $1.0 million) $323.3 million from the 2017 Term Loan (net of unamortized deferred financing costs of $1.7 million) as of December 31, 2017.
Mack-Cali Realty LP [Member]
Debt Disclosure [Line Items]
Unsecured Revolving Credit Facility And Term Loans	8. UNSECURED REVOLVING CREDIT FACILITY AND TERM LOANS  On January 25, 2017, the Company entered into an amended revolving credit facility and new term loan agreement (“2017 Credit Agreement”) with a group of 13 lenders. Pursuant to the 2017 Credit Agreement, the Company refinanced its existing $600 million unsecured revolving credit facility (“2017 Credit Facility”) and entered into a new $325 million unsecured, delayed draw term loan facility (“2017 Term Loan”). Effective March 6, 2018, the Company elected to determine its interest rate under the 2017 Credit Agreement and under the 2017 Term Loan using the defined leverage ratio option, resulting in an interest rate of LIBOR plus 130 basis points and LIBOR plus 155 basis points, respectively.  The terms of the 2017 Credit Facility include: (1) a four -year term ending in January 2021 , with two six -month extension options; (2) revolving credit loans may be made to the Company in an aggregate principal amount of up to $600 million (subject to increase as discussed below), with a sublimit under the 2017 Credit Facility for the issuance of letters of credit in an amount not to exceed $60 million (subject to increase as discussed below); (3) an interest rate, based on the Operating Partnership’s unsecured debt ratings from Moody’s or S&P, or, at the Operating Partnership’s option, if it no longer maintains a debt rating from Moody’s or S&P or such debt ratings fall below Baa3 and BBB-, based on a defined leverage ratio; and (4) a facility fee, currently 25 basis points, payable quarterly based on the Operating Partnership’s unsecured debt ratings from Moody’s or S&P, or, at the Operating Partnership’s option, if it no longer maintains a debt rating from Moody’s or S&P or such debt ratings fall below Baa3 and BBB-, based on a defined leverage ratio.  After electing to use the defined leverage ratio to determine the interest rate, the interest rates on outstanding borrowings, alternate base rate loans and the facility fee on the current borrowing capacity, payable quarterly in arrears, on the 2017 Credit Facility are currently based on the following total leverage ratio grid:    Interest Rate -  Applicable Basis Points  Interest Rate - Above LIBOR for  Applicable Basis Alternate Base Rate Facility Fee  Total Leverage Ratio Points above LIBOR Loans Basis Points  < 45% 125.0 25.0 20.0  ≥ 45% and <50% (current ratio) 130.0 30.0 25.0  ≥ 50% and <55% 135.0 35.0 30.0  ≥ 55% 160.0 60.0 35.0  Prior to the election to use the defined leverage ratio option, the interest rates on outstanding borrowings, alternate base rate loans and the facility fee on the current borrowing capacity, payable quarterly in arrears, on the 2017 Credit Facility were based upon the Operating Partnership’s unsecured debt ratings, as follows:     Interest Rate -  Applicable Basis Points  Operating Partnership's Interest Rate - Above LIBOR for  Unsecured Debt Ratings: Applicable Basis Points Alternate Base Rate Facility Fee  Higher of S&P or Moody's Above LIBOR Loans Basis Points  No ratings or less than BBB-/Baa3 155.0 55.0 30.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 120.0 20.0 25.0  BBB or Baa2 100.0 0.0 20.0  BBB+ or Baa1 90.0 0.0 15.0  A- or A3 or higher 87.5 0.0 12.5   The terms of the 2017 Term Loan include: (1) a three -year term ending in January 2020 , with two one -year extension options; (2) multiple draws of the term loan commitments may be made within 12 months of the effective date of the 2017 Credit Agreement up to an aggregate principal amount of $325 million (subject to increase as discussed below), with no requirement to be drawn in full; provided, that, if the Company does not borrow at least 50 percent of the initial term commitment from the term lenders (i.e. 50 percent of $325 million) on or before July 25, 2017, the amount of unused term loan commitments shall be reduced on such date so that, after giving effect to such reduction, the amount of unused term loan commitments is not greater than the outstanding term loans on such date; (3) a n interest rate based on the Operating Partnership’s unsecured debt ratings from Moody’s or S&P, or, at the Operating Partnership’s option if it no longer maintains a debt rating from Moody’s or S&P or such debt ratings fall below Baa3 and BBB-, based on a defined leverage ratio; and (4) a term commitment fee on any unused term loan commitment during the first 12 months after the effective date of the 2017 Credit Agreement at a rate of 0.25 percent per annum on the sum of the average daily unused portion of the aggregate term loan commitments.  On March 22, 2017, the Company drew the full $325 million available under the 2017 Term Loan. On March 29, 2017, the Company executed interest rate swap arrangements to fix LIBOR with an aggregate average rate of 1.6473% for the swaps and a current aggregate fixed rate of 3.1973% on borrowings under the 2017 Term Loan.  After electing to use the defined leverage ratio to determine the interest rate, the interest rate under the 2017 Term Loan is currently based on the following total leverage ratio grid:    Interest Rate -  Applicable Basis Points  Interest Rate - Above LIBOR for  Applicable Basis Alternate Base Rate  Total Leverage Ratio Points above LIBOR Loans  < 45% 145.0 45.0  ≥ 45% and < 50% (current ratio) 155.0 55.0  ≥ 50% and < 55% 165.0 65.0  ≥ 55% 195.0 95.0  Prior to the election to use the defined leverage ratio option, the interest rate on the 2017 Term Loan was based upon the Operating Partnership's unsecured debt ratings, as follows:     Interest Rate -  Applicable Basis Points  Operating Partnership's Interest Rate - Above LIBOR for  Unsecured Debt Ratings: Applicable Basis Points Alternate Base Rate  Higher of S&P or Moody's Above LIBOR Loans  No ratings or less than BBB-/Baa3 185.0 85.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 140.0 40.0  BBB or Baa2 115.0 15.0  BBB+ or Baa1 100.0 0.0  A- or A3 or higher 90.0 0.0   On up to four occasions at any time after the effective date of the 2017 Credit Agreement , the Company may elect to request (1) an increase to the existing revolving credit commitments (any such increase, the “New Revolving Credit Commitments”) and/or (2) the establishment of one or more new term loan commitments (the “New Term Commitments”, together with the 2017 Credit Commitments, the “Incremental Commitments”), by up to an aggregate amount not to exceed $350 million for all Incremental Commitments. The Company may also request that the sublimit for letters of credit available under the 2017 Credit Facility be increased to $100 million (without arranging any New Revolving Credit Commitments). No lender or letter of credit issued has any obligation to accept any Incremental Commitment or any increase to the letter of credit subfacility. There is no premium or penalty associated with full or partial prepayment of borrowings under the 2017 Credit Agreement. The 2017 Credit Agreement, which applies to both the 2017 Credit Facility and 2017 Term Loan, includes 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 2017 Credit Agreement (described below), or (ii) the property dispositions are completed while the Company is under an event of default under the 2017 Credit Agreement, 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 entire outstanding balance under the 2017 Credit Agreement may (or, in the case of any bankruptcy event of default, shall) become immediately due and payable, and the Company will not make any excess distributions except to enable the General Partner to continue to qualify as a REIT under the IRS Code.  Before it amended and restated its unsecured revolving credit facility in January 2017, the Company had a $600 million unsecured revolving credit facility with a group of 17 lenders that was scheduled to mature in July 2017. 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, was based upon the Operating Partnership’s unsecured debt ratings at the time, 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 (since January 2017 amendment) 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  In January 2016, the Company obtained a $350 million unsecured term loan (“2016 Term Loan”), which matures in January 2019 with two one ‑year extension options. On January 7, 2019, the Company exercised the first one -year extension option with the payment of an extension fee of $0.5 million, which extended the maturity of the 2016 Term Loan to January 2020 . The interest rate for the term loan is based on the Operating Partnership’s unsecured debt ratings, or, at the Company's option, a defined leverage ratio. Effective March 6, 2018, the Company elected to determine its interest rate under the 2016 Term Loan using the defined leverage ratio option, resulting in an interest rate of LIBOR plus 155 basis points. The Company entered into interest rate swap arrangements to fix LIBOR for the duration of the term loan. Including costs, the current all-in fixed rate is 3.28 percent. The proceeds from the loan were used primarily to repay outstanding borrowings on the Company’s then existing unsecured revolving credit facility and to repay $200 million senior unsecured notes that matured on January 15, 2016 .  After electing to use the defined leverage ratio to determine the interest rate, the interest rate under the 2016 Term Loan is currently based on the following total leverage ratio grid:    Interest Rate -  Applicable Basis  Total Leverage Ratio Points above LIBOR  < 45% 145.0  ≥ 45% and < 50% (current ratio) 155.0  ≥ 50% and < 55% 165.0  ≥ 55% 195.0  Prior to the election to use the defined interest leverage ratio option, the interest rate on the 2016 Term Loan was based upon the Operating Partnership’s unsecured debt ratings, as follows:    Operating Partnership's Interest Rate -  Unsecured Debt Ratings: Applicable Basis Points  Higher of S&P or Moody's Above LIBOR  No ratings or less than BBB-/Baa3 185.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 140.0  BBB or Baa2 115.0  BBB+ or Baa1 100.0  A- or A3 or higher 90.0  The terms of the 2016 Term Loan 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 term loan described below, or (ii) the property dispositions are completed while the Company is under an event of default under the term loan, 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 General Partner to continue to qualify as a REIT under the IRS Code.  On August 30, 2018, the Company entered into an amendment to the 2017 Credit Agreement (the “2017 Credit Agreement Amendment”) and an amendment to the 2016 Term Loan (the “2016 Term Loan Amendment”).  Each of the 2017 Credit Agreement Amendment and the 2016 Term Loan Amendment is effective as of June 30, 2018 and provides for the following material amendments to the terms of both the 2017 Credit Agreement and 2016 Term Loan):  1. The unsecured debt ratio covenant has been modified with respect to the measurement of the unencumbered collateral pool of assets in the calculation of such ratio for the period commencing July 1, 2018 and continuing until December 31, 2019 to allow the Operating Partnership to utilize the “as-is” appraised value of the properties known as ‘Harborside Plaza I’ and ‘Harborside Plaza V’ properties located in Jersey City, NJ in such calculation; and 2. A new covenant has been added that prohibits the Company from making any optional or voluntary payment, repayment, repurchase or redemption of any unsecured indebtedness of the Company (or any subsidiaries) that matures after January 25, 2022, at any time when any of the Total Leverage Ratio or the unsecured debt ratio covenants exceeds 60 percent (all as defined in the 2017 Credit Agreement and the 2016 Term Loan) or an appraisal is being used to determine the value of Harborside Plaza I and Harborside Plaza V for the unsecured debt ratio covenant.  All other terms and conditions of the 2017 Credit Agreement and the 2016 Term Loan remain unchanged.  The Company was in compliance with its debt covenants under its unsecured revolving credit facility and term loans as of December 31, 2018 .  As of December 31, 2018 and 2017 , the Company’s unsecured credit facility and term loans totaled $790.9 million and $822.3 million, respectively, comprised of: $117 million of outstanding borrowings under its unsecured revolving credit facility, $350.0 million from the 2016 Term Loan and $323.9 million from the 2017 Term Loan (net of unamortized deferred financing costs of $1.1 million) as of December 31, 2018 , and $150 million of outstanding borrowings under its unsecured revolving credit facility and $349.0 million from the 2016 Term Loan (net of unamortized deferred financing costs of $1.0 million) $323.3 million from the 2017 Term Loan (net of unamortized deferred financing costs of $1.7 million) as of December 31, 2017.

Mortgages, Loans Payable And Ot

Mortgages, Loans Payable And Other Obligations	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Line Items]
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, land and development projects. As of December 31, 2018 , 16 of the Company’s properties, with a total carrying value of approximately $ 2.1 billion, and one of the Company’s land and development projects, with a total carrying value of approximately $142 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. The Company was in compliance with its debt covenants under its mortgages and loans payable as of December 31, 2018 .  A summary of the Company’s mortgages, loans payable and other obligations as of December 31, 2018 and 2017 is as follows (dollars in thousands) :    Effective December 31, December 31,  Property/Project Name Lender Rate (a) 2018 2017 Maturity  Harborside Plaza 5 (b) The Northwestern Mutual Life Insurance Co. 6.84 % $ - $ 209,257  & New York Life Insurance Co.  23 Main Street (c) Berkadia CMBS 5.59 % - 27,090  One River Center (d) Guardian Life Insurance Co. 7.31 % - 40,485  Park Square (e) Wells Fargo Bank N.A. LIBOR+1.87 % 25,167 26,567 04/10/19  250 Johnson (f) M&T Bank LIBOR+2.35 % 41,769 32,491 05/20/19  Port Imperial 4/5 Hotel (g) Fifth Third Bank & Santander LIBOR+4.50 % 73,350 43,674 10/06/19  Worcester (h) Citizens Bank LIBOR+2.50 % 56,892 37,821 12/10/19  Monaco (i) The Northwestern Mutual Life Insurance Co. 3.15 % 168,370 169,987 02/01/21  Port Imperial South 4/5 Retail American General Life & A/G PC 4.56 % 4,000 4,000 12/01/21  Portside 7 CBRE Capital Markets/FreddieMac 3.57 % 58,998 58,998 08/01/23  Alterra I & II Capital One/FreddieMac 3.85 % 100,000 100,000 02/01/24  The Chase at Overlook Ridge New York Community Bank 3.74 % 135,750 135,750 01/01/25  Portside 5/6 (j) New York Life Insurance Company 4.56 % 97,000 45,778 03/10/26  Marbella New York Life Insurance Company 4.17 % 131,000 - 08/10/26  101 Hudson Wells Fargo CMBS 3.20 % 250,000 250,000 10/11/26  Short Hills Portfolio (k) Wells Fargo CMBS 4.15 % 124,500 124,500 04/01/27  150 Main St. Natixis Real Estate Capital LLC 4.48 % 41,000 41,000 08/05/27  Port Imperial South 11 (l) The Northwestern Mutual Life Insurance Co. 4.52 % 100,000 46,113 01/10/29  Port Imperial South 4/5 Garage American General Life & A/G PC 4.85 % 32,600 32,600 12/01/29   Principal balance outstanding 1,440,396 1,426,111  Unamortized deferred financing costs (8,998) (7,976)   Total mortgages, loans payable and other obligations, net $ 1,431,398 $ 1,418,135      (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 January 8, 2018 , the Company prepaid this loan in full upon payment of a fee of approximately $8.4 million using borrowings from the Company's unsecured revolving credit facility.  (c) On March 1, 2018, the Company prepaid this loan in full upon payment of a fee of approximately $0.1 million using borrowings from the Company's unsecured revolving credit facility.  (d) Mortgage was collateralized by the three properties comprising One River Center. On March 29, 2018 , the Company prepaid this loan in full upon payment of a fee of approximately $1.8 million using borrowings from the Company's unsecured revolving credit facility.  (e) On January 16, 2019, the loan was repaid using proceeds from the disposition of Park Square.  (f) This construction loan has a maximum borrowing capacity of $42 million and provides, subject to certain conditions, a one -year extension option with a fee of 25 basis points.  (g) This construction loan has a maximum borrowing capacity of $94 million and provides, subject to certain conditions, two one -year extension options with a fee of 20 basis points for each year. See Note 12: Commitments and Contingencies - Construction Projects.  (h) This construction loan has a maximum borrowing capacity of $58 million and provides, subject to certain conditions, two one -year extension options with a fee of 15 basis points each year.  (i) This mortgage loan, which includes unamortized fair value adjustment of $3.4 million as of December 31, 2018, was assumed by the Company in April 2017 with the acquisition and consolidation of all the interests in the Monaco Towers property.  (j) On December 7, 2018 , the Company refinanced this loan, due to which unamortized deferred financing costs of $0.2 million pertaining to the initial loan were written off. Concurrent with the refinancing, the Company repaid in full the property's $70 million construction loan and obtained a new loan in the amount of $97 million.  (k) This mortgage loan was obtained by the Company in March 2017 to partially fund the acquisition of the Short Hills/Madison portfolio.  (l) On December 17, 2018, the Company refinanced this loan, due to which unamortized deferred financing costs of $0.3 million pertaining to the initial loan were written off. Concurrent with the refinancing, the Company repaid in full the property's $70.1 million construction loan and obtained a new loan in the amount of $100 million.  SCHEDULED PRINCIPAL PAYMENTS Scheduled principal payments for the Company’s senior unsecured notes (see Note 7), unsecured revolving credit facility and term loan (see Note 8) and mortgages, loans payable and other obligations as of December 31, 2018 are as follows (dollars in thousands) :       Scheduled Principal  Period Amortization Maturities Total  2019 (a) $ 532 $ 546,711 $ 547,243  2020 2,903 325,000 327,903  2021 3,227 285,800 289,027  2022 3,284 300,000 303,284  2023 3,412 333,998 337,410  Thereafter 7,230 991,929 999,159  Sub-total 20,588 2,783,438 2,804,026  Adjustment for unamortized debt  discount/premium, net  December 31, 2018 (2,838) - (2,838)  Unamortized mark to market 3,370 - 3,370  Unamortized deferred financing costs (11,907) (11,907)   Totals/Weighted Average $ 9,213 $ 2,783,438 $ 2,792,651  (a) On January 7, 2019, the Company exercised the first one -year extension option on the $350 million term loan scheduled to mature in January 2019 , which extended the maturity of the 2016 Term Loan to January 2020 .  CASH PAID FOR INTEREST AND INTEREST CAPITALIZED Cash paid for interest for the year s ended December 31, 2018 , 2017 and 2016 was $ 97,744,000 , $ 103,559,000 and $ 122,414,000 , respectively. Interest capitalized by the Company for the year s ended December 31, 2018 , 2017 and 2016 was $ 27,047,000 , $ 20,240,000 , and $ 19,316,000 , respectively (which amounts included $816,000 , $1,056,000 and $5,055,000 for the year s ended December 31, 2018 , 2017 and 2016 , respectively, of interest capitalized on the Company’s investments in unconsolidated joint ventures which were substantially in development).  SUMMARY OF INDEBTEDNESS As of December 31, 2018 , the Company’s total indebtedness of $ 2,807,396,000 (weighted average interest rate of 3.89 percent) was comprised of $ 314,177,000 of unsecured revolving credit facility borrowings and other variable rate mortgage debt (weighted average rate of 4.90 percent) and fixed rate debt and other obligations of $ 2,493,219,000 (weighted average rate of 3.76 percent).  As of December 31, 2017 , the Company’s total indebtedness of $ 2,826,110,000 (weighted average interest rate of 3.93 percent) was comprised of $ 382,443,000 of unsecured revolving credit facility borrowings and other variable rate mortgage debt (weighted average rate of 3.63 percent) and fixed rate debt and other obligations of $ 2,443,667,000 (weighted average rate of 3.98 percent).
Mack-Cali Realty LP [Member]
Debt Disclosure [Line Items]
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, land and development projects. As of December 31, 2018 , 16 of the Company’s properties, with a total carrying value of approximately $ 2.1 billion, and one of the Company’s land and development projects, with a total carrying value of approximately $142 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. The Company was in compliance with its debt covenants under its mortgages and loans payable as of December 31, 2018 .  A summary of the Company’s mortgages, loans payable and other obligations as of December 31, 2018 and 2017 is as follows (dollars in thousands) :    Effective December 31, December 31,  Property/Project Name Lender Rate (a) 2018 2017 Maturity  Harborside Plaza 5 (b) The Northwestern Mutual Life Insurance Co. 6.84 % $ - $ 209,257  & New York Life Insurance Co.  23 Main Street (c) Berkadia CMBS 5.59 % - 27,090  One River Center (d) Guardian Life Insurance Co. 7.31 % - 40,485  Park Square (e) Wells Fargo Bank N.A. LIBOR+1.87 % 25,167 26,567 04/10/19  250 Johnson (f) M&T Bank LIBOR+2.35 % 41,769 32,491 05/20/19  Port Imperial 4/5 Hotel (g) Fifth Third Bank & Santander LIBOR+4.50 % 73,350 43,674 10/06/19  Worcester (h) Citizens Bank LIBOR+2.50 % 56,892 37,821 12/10/19  Monaco (i) The Northwestern Mutual Life Insurance Co. 3.15 % 168,370 169,987 02/01/21  Port Imperial South 4/5 Retail American General Life & A/G PC 4.56 % 4,000 4,000 12/01/21  Portside 7 CBRE Capital Markets/FreddieMac 3.57 % 58,998 58,998 08/01/23  Alterra I & II Capital One/FreddieMac 3.85 % 100,000 100,000 02/01/24  The Chase at Overlook Ridge New York Community Bank 3.74 % 135,750 135,750 01/01/25  Portside 5/6 (j) New York Life Insurance Company 4.56 % 97,000 45,778 03/10/26  Marbella New York Life Insurance Company 4.17 % 131,000 - 08/10/26  101 Hudson Wells Fargo CMBS 3.20 % 250,000 250,000 10/11/26  Short Hills Portfolio (k) Wells Fargo CMBS 4.15 % 124,500 124,500 04/01/27  150 Main St. Natixis Real Estate Capital LLC 4.48 % 41,000 41,000 08/05/27  Port Imperial South 11 (l) The Northwestern Mutual Life Insurance Co. 4.52 % 100,000 46,113 01/10/29  Port Imperial South 4/5 Garage American General Life & A/G PC 4.85 % 32,600 32,600 12/01/29   Principal balance outstanding 1,440,396 1,426,111  Unamortized deferred financing costs (8,998) (7,976)   Total mortgages, loans payable and other obligations, net $ 1,431,398 $ 1,418,135      (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 January 8, 2018 , the Company prepaid this loan in full upon payment of a fee of approximately $8.4 million using borrowings from the Company's unsecured revolving credit facility.  (c) On March 1, 2018, the Company prepaid this loan in full upon payment of a fee of approximately $0.1 million using borrowings from the Company's unsecured revolving credit facility.  (d) Mortgage was collateralized by the three properties comprising One River Center. On March 29, 2018 , the Company prepaid this loan in full upon payment of a fee of approximately $1.8 million using borrowings from the Company's unsecured revolving credit facility.  (e) On January 16, 2019, the loan was repaid using proceeds from the disposition of Park Square.  (f) This construction loan has a maximum borrowing capacity of $42 million and provides, subject to certain conditions, a one -year extension option with a fee of 25 basis points.  (g) This construction loan has a maximum borrowing capacity of $94 million and provides, subject to certain conditions, two one -year extension options with a fee of 20 basis points for each year. See Note 12: Commitments and Contingencies - Construction Projects.  (h) This construction loan has a maximum borrowing capacity of $58 million and provides, subject to certain conditions, two one -year extension options with a fee of 15 basis points each year.  (i) This mortgage loan, which includes unamortized fair value adjustment of $3.4 million as of December 31, 2018, was assumed by the Company in April 2017 with the acquisition and consolidation of all the interests in the Monaco Towers property.  (j) On December 7, 2018 , the Company refinanced this loan, due to which unamortized deferred financing costs of $0.2 million pertaining to the initial loan were written off. Concurrent with the refinancing, the Company repaid in full the property's $70 million construction loan and obtained a new loan in the amount of $97 million.  (k) This mortgage loan was obtained by the Company in March 2017 to partially fund the acquisition of the Short Hills/Madison portfolio.  (l) On December 17, 2018, the Company refinanced this loan, due to which unamortized deferred financing costs of $0.3 million pertaining to the initial loan were written off. Concurrent with the refinancing, the Company repaid in full the property's $70.1 million construction loan and obtained a new loan in the amount of $100 million.  SCHEDULED PRINCIPAL PAYMENTS Scheduled principal payments for the Company’s senior unsecured notes (see Note 7), unsecured revolving credit facility and term loan (see Note 8) and mortgages, loans payable and other obligations as of December 31, 2018 are as follows (dollars in thousands) :       Scheduled Principal  Period Amortization Maturities Total  2019 (a) $ 532 $ 546,711 $ 547,243  2020 2,903 325,000 327,903  2021 3,227 285,800 289,027  2022 3,284 300,000 303,284  2023 3,412 333,998 337,410  Thereafter 7,230 991,929 999,159  Sub-total 20,588 2,783,438 2,804,026  Adjustment for unamortized debt  discount/premium, net  December 31, 2018 (2,838) - (2,838)  Unamortized mark to market 3,370 - 3,370  Unamortized deferred financing costs (11,907) (11,907)   Totals/Weighted Average $ 9,213 $ 2,783,438 $ 2,792,651  (a) On January 7, 2019, the Company exercised the first one -year extension option on the $350 million term loan scheduled to mature in January 2019 , which extended the maturity of the 2016 Term Loan to January 2020 .  CASH PAID FOR INTEREST AND INTEREST CAPITALIZED Cash paid for interest for the year s ended December 31, 2018 , 2017 and 2016 was $ 97,744,000 , $ 103,559,000 and $ 122,414,000 , respectively. Interest capitalized by the Company for the year s ended December 31, 2018 , 2017 and 2016 was $ 27,047,000 , $ 20,240,000 , and $ 19,316,000 , respectively (which amounts included $816,000 , $1,056,000 and $5,055,000 for the year s ended December 31, 2018 , 2017 and 2016 , respectively, of interest capitalized on the Company’s investments in unconsolidated joint ventures which were substantially in development).  SUMMARY OF INDEBTEDNESS As of December 31, 2018 , the Company’s total indebtedness of $ 2,807,396,000 (weighted average interest rate of 3.89 percent) was comprised of $ 314,177,000 of unsecured revolving credit facility borrowings and other variable rate mortgage debt (weighted average rate of 4.90 percent) and fixed rate debt and other obligations of $ 2,493,219,000 (weighted average rate of 3.76 percent).  As of December 31, 2017 , the Company’s total indebtedness of $ 2,826,110,000 (weighted average interest rate of 3.93 percent) was comprised of $ 382,443,000 of unsecured revolving credit facility borrowings and other variable rate mortgage debt (weighted average rate of 3.63 percent) and fixed rate debt and other obligations of $ 2,443,667,000 (weighted average rate of 3.98 percent).

Employee Benefit 401(k) Plans

Employee Benefit 401(k) Plans	12 Months Ended
	Dec. 31, 2018
Compensation And Retirement Disclosure [Line Items]
Employee Benefit 401(k) Plans	10. EMPLOYEE BENEFIT 401(k) PLANS  Employees of the General Partner, 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 years ended December 31, 2018 , 2017 and 2016 was $ 886,000 , $ 1,055,000 and $ 1,029,000 , respectively.
Mack-Cali Realty LP [Member]
Compensation And Retirement Disclosure [Line Items]
Employee Benefit 401(k) Plans	10. EMPLOYEE BENEFIT 401(k) PLANS  Employees of the General Partner, 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 years ended December 31, 2018 , 2017 and 2016 was $ 886,000 , $ 1,055,000 and $ 1,029,000 , respectively.

Disclosure Of Fair Value Of Ass

Disclosure Of Fair Value Of Assets And Liabilities	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Line Items]
Disclosure Of Fair Value Of Assets And Liabilities	11. DISCLOSURE OF FAIR VALUE OF ASSETS AND LIABILITIES  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 assets and liabilities at December 31, 2018 and 2017 . 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 December 31, 2018 and 2017 .  The fair value of the Company’s long-term debt, consisting of senior unsecured notes, unsecured term loans, an unsecured revolving credit facility and mortgages, loans payable and other obligations aggregated approximately $ 2,711,712,000 and $ 2,764,033,000 as compared to the book value of approximately $ 2,792,651,000 and $ 2,809,568,000 as of December 31, 2018 and 2017 , 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.  The fair value measurements used in the evaluation of the Company’s rental properties are considered to be Level 3 valuations within the fair value hierarchy, as there are significant unobservable inputs. Examples of inputs that were utilized in the fair value calculations include estimated holding periods, discount rates, market capitalization rates, expected lease rental rates, and third party broker information.  Valuations of rental property identified as held for sale are based on estimated sale prices, net of estimated selling costs, of such property.  The Company identified as held for sale six office properties and a 159 unit multi-family rental property as of December 31, 2018 with an aggregate carrying value for the rental property of $108.8 million. The total estimated sales proceeds, net of expected selling costs, from the sales are expected to be approximately $124 million. The Company determined that the carrying value of four of the properties was not expected to be recovered from estimated net sales proceeds and accordingly recognized an unrealized loss allowance of $20.1 million for the year ended December 31, 2018 .  The Company identified as held for sale 21 office properties as of December 31, 2017 with an aggregate carrying value of $171.6 million. The total estimated sales proceeds from the sales were expected to be approximately $223 million. The Company determined that the carrying value of seven of these properties was not expected to be recovered from estimated net sales proceeds and accordingly recognized an unrealized loss allowance of $12.3 million during the year ended December 31, 2017.  The Company owns two separate developable land parcels in Conshohocken and Bala Cynwyd, Pennsylvania, that were being considered for development into multi-family rental properties. During the fourth quarter 2018, the Company made the decision to pursue selling the land parcels as opposed to development. Due to the shortening of the expected periods of ownership, the Company determined that it was necessary to reduce the carrying values of the land parcels to their estimated fair values (ascertained by broker opinions of value obtained during the marketing process) and recorded a land impairments charge of $24.6 million at December 31, 2018.  Disclosure about fair value of assets and liabilities is based on pertinent information available to management as of December 31, 2018 and 2017 . 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 December 31, 2018 and current estimates of fair value may differ significantly from the amounts presented herein.
Mack-Cali Realty LP [Member]
Fair Value Disclosures [Line Items]
Disclosure Of Fair Value Of Assets And Liabilities	11. DISCLOSURE OF FAIR VALUE OF ASSETS AND LIABILITIES  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 assets and liabilities at December 31, 2018 and 2017 . 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 December 31, 2018 and 2017 .  The fair value of the Company’s long-term debt, consisting of senior unsecured notes, unsecured term loans, an unsecured revolving credit facility and mortgages, loans payable and other obligations aggregated approximately $ 2,711,712,000 and $ 2,764,033,000 as compared to the book value of approximately $ 2,792,651,000 and $ 2,809,568,000 as of December 31, 2018 and 2017 , 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.  The fair value measurements used in the evaluation of the Company’s rental properties are considered to be Level 3 valuations within the fair value hierarchy, as there are significant unobservable inputs. Examples of inputs that were utilized in the fair value calculations include estimated holding periods, discount rates, market capitalization rates, expected lease rental rates, and third party broker information.  Valuations of rental property identified as held for sale are based on estimated sale prices, net of estimated selling costs, of such property.  The Company identified as held for sale six office properties and a 159 unit multi-family rental property as of December 31, 2018 with an aggregate carrying value for the rental property of $108.8 million. The total estimated sales proceeds, net of expected selling costs, from the sales are expected to be approximately $124 million. The Company determined that the carrying value of four of the properties was not expected to be recovered from estimated net sales proceeds and accordingly recognized an unrealized loss allowance of $20.1 million for the year ended December 31, 2018 .  The Company identified as held for sale 21 office properties as of December 31, 2017 with an aggregate carrying value of $171.6 million. The total estimated sales proceeds from the sales were expected to be approximately $223 million. The Company determined that the carrying value of seven of these properties was not expected to be recovered from estimated net sales proceeds and accordingly recognized an unrealized loss allowance of $12.3 million during the year ended December 31, 2017.  The Company owns two separate developable land parcels in Conshohocken and Bala Cynwyd, Pennsylvania, that were being considered for development into multi-family rental properties. During the fourth quarter 2018, the Company made the decision to pursue selling the land parcels as opposed to development. Due to the shortening of the expected periods of ownership, the Company determined that it was necessary to reduce the carrying values of the land parcels to their estimated fair values (ascertained by broker opinions of value obtained during the marketing process) and recorded a land impairments charge of $24.6 million at December 31, 2018.  Disclosure about fair value of assets and liabilities is based on pertinent information available to management as of December 31, 2018 and 2017 . 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 December 31, 2018 and current estimates of fair value may differ significantly from the amounts presented herein.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies [Line Items]
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 $ 1.1 million, $1.1 million and $ 1.1 million for the years ended December 31, 2018 , 2017 and 2016 , 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 $ 4.4 million, $ 3.9 million and $ 3.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively.  The Port Imperial 4/5 Garage development project agreement with the City of Weehawken had a term of five years beginning when the project was substantially complete, which occurred in 2013. The agreement, which expired in December 2018, provided that real estate taxes be paid initially on the land value of the project only and allowed for a phase in of real estate taxes on the value of the improvements at zero percent year one and 80 percent in years two through five.  The Port Imperial South 1/3 Garage development project agreement with the City of Weehawken has a term of five years beginning when the project is substantially complete, which occurred in the fourth quarter of 2015. The agreement provides that real estate taxes be paid at 100 percent on the land value of the project only over the five year period and allows for a phase in of real estate taxes on the building improvement value at zero percent in year one and 95 percent in years two through five.  The Port Imperial Hotel development project agreement with the City of Weehawken is for a term of 15 years following substantial completion, which commenced initial operation in December 2018. The annual PILOT is equal to two percent of Total Project Costs, as defined therein.  The Port Imperial South 11 development project agreement with the City of Weehawken is for a term of 15 years following substantial completion, which occurred in August 2018. The annual PILOT is equal to 10 percent of Gross Revenues, as defined therein.  The 111 River Realty agreement with the City of Hoboken, which commenced on October 1, 2001 expires in April 2022. The PILOT payment equaled $1.2 million annually through April 2017 and then increased to $1.4 million annually until expiration. The PILOT totaled $1.4 million, $1.3 million and $0.6 million for the years ended December 31, 2018 , 2017 and 2016, respectively.  The Monaco Towers agreement with the City of Jersey City, which commenced in 2011, is for a term of 10 years. The annual PILOT is equal to 10 percent of gross revenues, as defined. The PILOT totaled $2.4 million for the year ended December 31, 2018 and $1.6 million for the period from acquisition (April 2017) through December 31, 2017.  The Marbella Tower agreement with the City of Jersey City, which commenced in 2003, expired in December 2018. The annual PILOT was equal to 15 percent of gross revenues, as defined therein. The PILOT totaled $0.9 million for the period from acquisition (August 2018), through December 31, 2018 .  The Marbella II agreement with the City of Jersey City, which commenced in 2016, is for a term of 10 years. The annual PILOT is equal to 10 percent of gross revenues for Years 1-4, 12 percent of gross revenues for Years 5-8 and 14 percent of gross revenue for years 9-10, as defined therein.  The Port Imperial South Parcel 8/9 development project agreement with the City of Weehawken is for a term of 25 years following substantial completion, which is anticipated to occur in the fourth quarter 2020. The annual PILOT is equal to 11 percent of gross revenue for Years 1-10, 12.5 percent for Years 11-18 and 14 percent for Years 19-25, as defined therein.  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 December 31, 2018 , are as follows (dollars in thousands) :    Year Amount  2019 $ 2,470  2020 2,491  2021 2,491  2022 2,491  2023 2,491  2024 through 2084 210,117   Total $ 222,551  Ground lease expense incurred by the Company during the years ended December 31, 2018 , 2017 and 2016 amounted to $ 2.3 million, $ 2.6 million and $1.5 million, respectively.  CONSTRUCTION PROJECTS In 2015, the Company entered into a 90 -percent owned joint venture with XS Port Imperial Hotel, LLC to form XS Hotel Urban Renewal Associates LLC, which is developing a 372 -key hotel ( 164 keys Residence Inn and 208 keys Marriott Envue) in Weehawken, New Jersey. The Residence Inn opened in 4Q 2018 and the Marriott Envue is expected to open in 2Q 2019. The construction of the project is estimated to cost $159.9 million, with construction costs of $147.1 million incurred by the venture through December 31, 2018. The project costs are expected to be funded from a $94 million construction loan (with $73.4 million outstanding as of December 31, 2018).  The Company is developing a 313 -unit multi-family project known as Building 8/9 at Port Imperial in Weehawken, New Jersey, which began construction in third quarter 2018. The construction project, which is estimated to cost $142.6 million, of which construction costs of $35.4 million have been incurred through December 31, 2018, is expected to be ready for occupancy in fourth quarter 2020 . The Company is expected to fund $50.6 million of construction costs, of which the Company has funded $35.4 million as of December 31, 2018, and the remaining construction costs are expected to be funded primarily from a $92 million construction loan.  The Company is developing a 326 -unit multi-family project known as Chase III at Overlook Ridge in Malden, Massachusetts, which began construction in third quarter 2018. The construction project, which is estimated to cost $99.9 million, of which $20.2 million have been incurred through December 31, 2018, is expected to be ready for occupancy in fourth quarter 2020 . The Company is expected to fund $37.9 million of construction costs, of which the Company has funded $20.2 million as of December 31, 2018, and the remaining construction costs are expected to be funded primarily from a $62 million construction loan.  CHANGES IN EXECUTIVE OFFICERS On October 31, 2018, RRT entered into a separation and consulting agreement with Robert Andrew Marshall, the President and Executive Vice President of Development of RRT (the “Separation and Consulting Agreement”). Pursuant to the Separation and Consulting Agreement, Mr. Marshall’s employment with RRT was terminated, effective as of October 31, 2018 (the “Termination Date”), and Mr. Marshall has agreed to provide consulting services to RRT and the Company during the period beginning on November 1, 2018 and ending on March 31, 2019 (the “Consulting Period”).  Under the terms of the Separation and Consulting Agreement, Mr. Marshall will receive the following separation payments:  · accrued but unpaid base salary through October 31, 2018; · unreimbursed expenses incurred by Mr. Marshall prior to the Termination Date; and · COBRA payments through January 31, 2019, in an aggregate amount equal to approximately $7,533 . · In addition, during the Consulting Period, Mr. Marshall will receive a monthly consulting fee of $22,500 . · The Separation and Consulting Agreement provides that Mr. Marshall will continue to vest during the Consulting Period in all of the 22,120 Time-Based Long-Term Incentive Plan Awards originally issued in March 2016 (the “Vested 2016 Time-Based LTIP Awards”) and 28,880 of the 35,697 Performance-Based Long-Term Incentive Plan Awards originally issued in March 2016 (the “Vested 2016 Performance-Based LTIP Awards” and, together with the Vested 2016 Time-Based LTIP Awards, the “Vested 2016 LTIP Awards”). The Vested 2016 LTIP awards will vest on the earliest to occur of (i) Mr. Marshall’s death, (ii) the termination of Mr. Marshall’s consulting services by the Company for any reason other than for Cause (as defined in the Separation and Consulting Agreement) prior to March 31, 2019 or (iii) March 8, 2019 (such earliest date, the “Vesting Date”), subject to Mr. Marshall’s continuous performance of the consulting services through the applicable Vesting Date. All other equity awards previously issued to Mr. Marshall, including the remaining 6,817 Performance-Based LTIP Awards originally issued in March 2016, 4,449 Time-Based Long-Term Incentive Plan Awards originally issued in April 2017, 13,473 Performance-Based Long-Term Incentive Plan Awards originally issued in April 2017, 11,799 Time-Based Long-Term Incentive Plan Awards originally issued in April 2018, and 22,676 Performance-Based Long-Term Incentive Plan Awards originally issued in April 2018, expired and were forfeited and cancelled, effective as of the Termination Date. · The Separation and Consulting Agreement further provides that on the earliest to occur of (i) March 11, 2019, (ii) five (5) business days after RRT receives written notice of Mr. Marshall’s death, or (iii) the date on which Mr. Marshall’s consulting services are terminated by the Company for any reason other than for Cause, the Company will purchase from Mr. Marshall all of the Vested 2016 LTIP Awards for an aggregate purchase price in cash equal to the product of (x) the total number of Vested 2016 LTIP Awards (which will amount to a total of 51,000 ) and (y) the average closing price per share of the Company’s common stock, as reported on the New York Stock Exchange for the period of five trading days ending on the applicable Vesting Date.  The Company’s total estimated costs in connection with the departure of Mr. Marshall of approximately $0.1 million (net of a reversal of $0.3 million of amortization of stock compensation expense due to the forfeiture of the unvested securities) during the year ended December 31, 2018 was included in general and administrative expense (approximately $1.0 million was included in accounts payable, accrued expenses and other liabilities as of December 31, 2018).  In June 2018, the General Partner entered into a separation and general release agreement with Mitchell E. Rudin, pursuant to which Mr. Rudin’s employment with the Company as its Vice Chairman was terminated effective as of June 5, 2018.  Under the terms of the Rudin separation agreement, Mr. Rudin is entitled to receive the following separation payments:  · Accrued but unpaid base salary through June 5, 2018; · A lump sum cash payment of $2,558,082 ; · Payment of unreimbursed expenses incurred by Mr. Rudin prior to termination, in the amount of $50,000 in the aggregate; and · COBRA payments for up to 18 months after termination, in an amount equal to approximately $34,047 . · The Rudin separation agreement reflects that certain equity awards previously issued to Mr. Rudin, including time-vesting options, restricted stock units and performance share units, vested in full as of June 5, 2018 in accordance with their terms. Pursuant to the Rudin separation agreement, other than the equity awards that were fully vested as of June 5, 2018, as set forth in the Rudin separation agreement, all other equity awards granted to Mr. Rudin, including 32,311 LTIP Units subject to time-based vesting and 175,127 LTIP Units subject to performance-based vesting, expired and were immediately forfeited and canceled, effective as of June 5, 2018.  The Company’s total estimated costs in connection with the departure of Mr. Rudin of approximately $1.2 million (net of a reversal of $1.6 million of amortization of stock compensation expense due to the forfeiture of the unvested securities) during the year ended December 31, 2018 was included in general and administrative expense (approximately $23,000 was included in accounts payable, accrued expenses and other liabilities as of December 31, 2018).  In January 2018, the Company announced the appointment of David J. Smetana as chief financial officer and Nicholas Hilton as executive vice president of leasing of the General Partner. Mr. Smetana began to perform his duties as chief financial officer and Anthony Krug ceased to serve as chief financial officer immediately following the filing of the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Mr. Krug remained an employee of the General Partner and provided transition services through March 31, 2018. Mr. Hilton’s employment commenced on February 12, 2018 following the departure of Christopher DeLorenzo. In connection with these management changes, the General Partner entered into a separation agreement and release with each of Messrs. Krug and DeLorenzo. Under the terms of the Krug separation agreement, Mr. Krug is entitled to receive the following severance benefits: · Earned but unpaid compensation through the date of termination, including base salary, 2017 bonus (when determined), a pro rata portion of his annual car allowance, and any unused vacation time; · A lump sum cash severance payment of $1,312,500 ; · A prorated portion of his 2018 target bonus equal to $93,750 ; · COBRA payments for up to two years after termination, in an amount equal to approximately $42,000 ; and · Accelerated vesting of all unvested LTIP units in the Operating Partnership, consisting of 13,306 LTIP units subject to time-based vesting and 18,665 LTIP units subject to performance-based vesting, with LTIP units subject to performance-based vesting criteria vesting at target performance.  Under the terms of the DeLorenzo separation agreement, Mr. DeLorenzo is entitled to receive the following severance benefits: · Earned but unpaid compensation through the date of termination, including base salary, 2017 bonus (when determined), a pro rata portion of his annual car allowance, and any unused vacation time; · A lump sum cash severance payment of $500,000 ; · COBRA payments for up to 18 months after termination, in an amount equal to approximately $42,000 ; and · Partial accelerated vesting of unvested LTIP units in the Operating Partnership, consisting of 9,111 LTIP units subject to time based vesting and 13,982 LTIP units subject to performance-based vesting, with LTIP units subject to performance based vesting criteria vesting at target performance.  The Company’s total estimated costs in connection with the departure of Messrs. Krug and DeLorenzo of approximately $2.7 million during the year ended December 31, 2018 was included in general and administrative expense (approximately $43,000 was included in accounts payable, accrued expenses and other liabilities as of December 31, 2018).  OTHER On August 11, 2017, the Company acquired an existing mortgage note receivable encumbering a vacant developable land parcel located in Jersey City, New Jersey (the “Land Property”) with a balance of $44.7 million (the “Land Note Receivable”). The Land Note Receivable matures in July 2019 and earns interest at an annual rate of 5.85 percent which accrues monthly and is payable at maturity. In March 2018, the Company received a partial prepayment of $3 million. The Land Property is currently an unimproved land parcel which operates as a surface parking facility. Additionally, the Company entered into an agreement to acquire the Land Property, subject to the Company's ability to obtain all necessary development rights and entitlements to develop an apartment building on the land, and other related conditions to ensure that the Company can develop the project. The purchase price is $73 million, subject to adjustment based on the level of development rights obtained for the construction of a multifamily apartment building.  Through February 2016, the Company could not dispose of or distribute certain of its properties, which were originally contributed by certain unrelated common unitholders of the Operating Partnership, without the express written consent of such common unitholders, as applicable, except in a manner which did not result in recognition of any built-in-gain (which may result in an income tax liability) or which reimbursed the appropriate specific common unitholders for the tax consequences of the recognition of such built-in-gains (collectively, the “Property Lock-Ups”). Upon the expiration in February 2016 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 General Partner’s Board of Directors; David S. Mack, director; and Earle I. Mack, a former director), the Robert Martin Group (which includes Robert F. Weinberg, a former director and current member of the General Partner's Advisory Board), and the Cali Group (which includes John R. Cali, a former director and current member of the General Partner's Advisory Board). As of December 31, 2018 , after the effects of tax-free exchanges on certain of the originally contributed properties, either wholly or partially, over time, 79 of the Company’s properties, primarily a portfolio of flex properties in Westchester County, New York with an aggregate carrying value of approximately $ 1.4 billion, are subject to these conditions.
Mack-Cali Realty LP [Member]
Commitments And Contingencies [Line Items]
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 $ 1.1 million, $1.1 million and $ 1.1 million for the years ended December 31, 2018 , 2017 and 2016 , 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 $ 4.4 million, $ 3.9 million and $ 3.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively.  The Port Imperial 4/5 Garage development project agreement with the City of Weehawken had a term of five years beginning when the project was substantially complete, which occurred in 2013. The agreement, which expired in December 2018, provided that real estate taxes be paid initially on the land value of the project only and allowed for a phase in of real estate taxes on the value of the improvements at zero percent year one and 80 percent in years two through five.  The Port Imperial South 1/3 Garage development project agreement with the City of Weehawken has a term of five years beginning when the project is substantially complete, which occurred in the fourth quarter of 2015. The agreement provides that real estate taxes be paid at 100 percent on the land value of the project only over the five year period and allows for a phase in of real estate taxes on the building improvement value at zero percent in year one and 95 percent in years two through five.  The Port Imperial Hotel development project agreement with the City of Weehawken is for a term of 15 years following substantial completion, which commenced initial operation in December 2018. The annual PILOT is equal to two percent of Total Project Costs, as defined therein.  The Port Imperial South 11 development project agreement with the City of Weehawken is for a term of 15 years following substantial completion, which occurred in August 2018. The annual PILOT is equal to 10 percent of Gross Revenues, as defined therein.  The 111 River Realty agreement with the City of Hoboken, which commenced on October 1, 2001 expires in April 2022. The PILOT payment equaled $1.2 million annually through April 2017 and then increased to $1.4 million annually until expiration. The PILOT totaled $1.4 million, $1.3 million and $0.6 million for the years ended December 31, 2018 , 2017 and 2016, respectively.  The Monaco Towers agreement with the City of Jersey City, which commenced in 2011, is for a term of 10 years. The annual PILOT is equal to 10 percent of gross revenues, as defined. The PILOT totaled $2.4 million for the year ended December 31, 2018 and $1.6 million for the period from acquisition (April 2017) through December 31, 2017.  The Marbella Tower agreement with the City of Jersey City, which commenced in 2003, expired in December 2018. The annual PILOT was equal to 15 percent of gross revenues, as defined therein. The PILOT totaled $0.9 million for the period from acquisition (August 2018), through December 31, 2018 .  The Marbella II agreement with the City of Jersey City, which commenced in 2016, is for a term of 10 years. The annual PILOT is equal to 10 percent of gross revenues for Years 1-4, 12 percent of gross revenues for Years 5-8 and 14 percent of gross revenue for years 9-10, as defined therein.  The Port Imperial South Parcel 8/9 development project agreement with the City of Weehawken is for a term of 25 years following substantial completion, which is anticipated to occur in the fourth quarter 2020. The annual PILOT is equal to 11 percent of gross revenue for Years 1-10, 12.5 percent for Years 11-18 and 14 percent for Years 19-25, as defined therein.  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 December 31, 2018 , are as follows (dollars in thousands) :    Year Amount  2019 $ 2,470  2020 2,491  2021 2,491  2022 2,491  2023 2,491  2024 through 2084 210,117   Total $ 222,551  Ground lease expense incurred by the Company during the years ended December 31, 2018 , 2017 and 2016 amounted to $ 2.3 million, $ 2.6 million and $1.5 million, respectively.  CONSTRUCTION PROJECTS In 2015, the Company entered into a 90 -percent owned joint venture with XS Port Imperial Hotel, LLC to form XS Hotel Urban Renewal Associates LLC, which is developing a 372 -key hotel ( 164 keys Residence Inn and 208 keys Marriott Envue) in Weehawken, New Jersey. The Residence Inn opened in 4Q 2018 and the Marriott Envue is expected to open in 2Q 2019. The construction of the project is estimated to cost $159.9 million, with construction costs of $147.1 million incurred by the venture through December 31, 2018. The project costs are expected to be funded from a $94 million construction loan (with $73.4 million outstanding as of December 31, 2018).  The Company is developing a 313 -unit multi-family project known as Building 8/9 at Port Imperial in Weehawken, New Jersey, which began construction in third quarter 2018. The construction project, which is estimated to cost $142.6 million, of which construction costs of $35.4 million have been incurred through December 31, 2018, is expected to be ready for occupancy in fourth quarter 2020 . The Company is expected to fund $50.6 million of construction costs, of which the Company has funded $35.4 million as of December 31, 2018, and the remaining construction costs are expected to be funded primarily from a $92 million construction loan.  The Company is developing a 326 -unit multi-family project known as Chase III at Overlook Ridge in Malden, Massachusetts, which began construction in third quarter 2018. The construction project, which is estimated to cost $99.9 million, of which $20.2 million have been incurred through December 31, 2018, is expected to be ready for occupancy in fourth quarter 2020 . The Company is expected to fund $37.9 million of construction costs, of which the Company has funded $20.2 million as of December 31, 2018, and the remaining construction costs are expected to be funded primarily from a $62 million construction loan.  CHANGES IN EXECUTIVE OFFICERS On October 31, 2018, RRT entered into a separation and consulting agreement with Robert Andrew Marshall, the President and Executive Vice President of Development of RRT (the “Separation and Consulting Agreement”). Pursuant to the Separation and Consulting Agreement, Mr. Marshall’s employment with RRT was terminated, effective as of October 31, 2018 (the “Termination Date”), and Mr. Marshall has agreed to provide consulting services to RRT and the Company during the period beginning on November 1, 2018 and ending on March 31, 2019 (the “Consulting Period”).  Under the terms of the Separation and Consulting Agreement, Mr. Marshall will receive the following separation payments:  · accrued but unpaid base salary through October 31, 2018; · unreimbursed expenses incurred by Mr. Marshall prior to the Termination Date; and · COBRA payments through January 31, 2019, in an aggregate amount equal to approximately $7,533 . · In addition, during the Consulting Period, Mr. Marshall will receive a monthly consulting fee of $22,500 . · The Separation and Consulting Agreement provides that Mr. Marshall will continue to vest during the Consulting Period in all of the 22,120 Time-Based Long-Term Incentive Plan Awards originally issued in March 2016 (the “Vested 2016 Time-Based LTIP Awards”) and 28,880 of the 35,697 Performance-Based Long-Term Incentive Plan Awards originally issued in March 2016 (the “Vested 2016 Performance-Based LTIP Awards” and, together with the Vested 2016 Time-Based LTIP Awards, the “Vested 2016 LTIP Awards”). The Vested 2016 LTIP awards will vest on the earliest to occur of (i) Mr. Marshall’s death, (ii) the termination of Mr. Marshall’s consulting services by the Company for any reason other than for Cause (as defined in the Separation and Consulting Agreement) prior to March 31, 2019 or (iii) March 8, 2019 (such earliest date, the “Vesting Date”), subject to Mr. Marshall’s continuous performance of the consulting services through the applicable Vesting Date. All other equity awards previously issued to Mr. Marshall, including the remaining 6,817 Performance-Based LTIP Awards originally issued in March 2016, 4,449 Time-Based Long-Term Incentive Plan Awards originally issued in April 2017, 13,473 Performance-Based Long-Term Incentive Plan Awards originally issued in April 2017, 11,799 Time-Based Long-Term Incentive Plan Awards originally issued in April 2018, and 22,676 Performance-Based Long-Term Incentive Plan Awards originally issued in April 2018, expired and were forfeited and cancelled, effective as of the Termination Date. · The Separation and Consulting Agreement further provides that on the earliest to occur of (i) March 11, 2019, (ii) five (5) business days after RRT receives written notice of Mr. Marshall’s death, or (iii) the date on which Mr. Marshall’s consulting services are terminated by the Company for any reason other than for Cause, the Company will purchase from Mr. Marshall all of the Vested 2016 LTIP Awards for an aggregate purchase price in cash equal to the product of (x) the total number of Vested 2016 LTIP Awards (which will amount to a total of 51,000 ) and (y) the average closing price per share of the Company’s common stock, as reported on the New York Stock Exchange for the period of five trading days ending on the applicable Vesting Date.  The Company’s total estimated costs in connection with the departure of Mr. Marshall of approximately $0.1 million (net of a reversal of $0.3 million of amortization of stock compensation expense due to the forfeiture of the unvested securities) during the year ended December 31, 2018 was included in general and administrative expense (approximately $1.0 million was included in accounts payable, accrued expenses and other liabilities as of December 31, 2018).  In June 2018, the General Partner entered into a separation and general release agreement with Mitchell E. Rudin, pursuant to which Mr. Rudin’s employment with the Company as its Vice Chairman was terminated effective as of June 5, 2018.  Under the terms of the Rudin separation agreement, Mr. Rudin is entitled to receive the following separation payments:  · Accrued but unpaid base salary through June 5, 2018; · A lump sum cash payment of $2,558,082 ; · Payment of unreimbursed expenses incurred by Mr. Rudin prior to termination, in the amount of $50,000 in the aggregate; and · COBRA payments for up to 18 months after termination, in an amount equal to approximately $34,047 . · The Rudin separation agreement reflects that certain equity awards previously issued to Mr. Rudin, including time-vesting options, restricted stock units and performance share units, vested in full as of June 5, 2018 in accordance with their terms. Pursuant to the Rudin separation agreement, other than the equity awards that were fully vested as of June 5, 2018, as set forth in the Rudin separation agreement, all other equity awards granted to Mr. Rudin, including 32,311 LTIP Units subject to time-based vesting and 175,127 LTIP Units subject to performance-based vesting, expired and were immediately forfeited and canceled, effective as of June 5, 2018.  The Company’s total estimated costs in connection with the departure of Mr. Rudin of approximately $1.2 million (net of a reversal of $1.6 million of amortization of stock compensation expense due to the forfeiture of the unvested securities) during the year ended December 31, 2018 was included in general and administrative expense (approximately $23,000 was included in accounts payable, accrued expenses and other liabilities as of December 31, 2018).  In January 2018, the Company announced the appointment of David J. Smetana as chief financial officer and Nicholas Hilton as executive vice president of leasing of the General Partner. Mr. Smetana began to perform his duties as chief financial officer and Anthony Krug ceased to serve as chief financial officer immediately following the filing of the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Mr. Krug remained an employee of the General Partner and provided transition services through March 31, 2018. Mr. Hilton’s employment commenced on February 12, 2018 following the departure of Christopher DeLorenzo. In connection with these management changes, the General Partner entered into a separation agreement and release with each of Messrs. Krug and DeLorenzo. Under the terms of the Krug separation agreement, Mr. Krug is entitled to receive the following severance benefits: · Earned but unpaid compensation through the date of termination, including base salary, 2017 bonus (when determined), a pro rata portion of his annual car allowance, and any unused vacation time; · A lump sum cash severance payment of $1,312,500 ; · A prorated portion of his 2018 target bonus equal to $93,750 ; · COBRA payments for up to two years after termination, in an amount equal to approximately $42,000 ; and · Accelerated vesting of all unvested LTIP units in the Operating Partnership, consisting of 13,306 LTIP units subject to time-based vesting and 18,665 LTIP units subject to performance-based vesting, with LTIP units subject to performance-based vesting criteria vesting at target performance.  Under the terms of the DeLorenzo separation agreement, Mr. DeLorenzo is entitled to receive the following severance benefits: · Earned but unpaid compensation through the date of termination, including base salary, 2017 bonus (when determined), a pro rata portion of his annual car allowance, and any unused vacation time; · A lump sum cash severance payment of $500,000 ; · COBRA payments for up to 18 months after termination, in an amount equal to approximately $42,000 ; and · Partial accelerated vesting of unvested LTIP units in the Operating Partnership, consisting of 9,111 LTIP units subject to time based vesting and 13,982 LTIP units subject to performance-based vesting, with LTIP units subject to performance based vesting criteria vesting at target performance.  The Company’s total estimated costs in connection with the departure of Messrs. Krug and DeLorenzo of approximately $2.7 million during the year ended December 31, 2018 was included in general and administrative expense (approximately $43,000 was included in accounts payable, accrued expenses and other liabilities as of December 31, 2018).  OTHER On August 11, 2017, the Company acquired an existing mortgage note receivable encumbering a vacant developable land parcel located in Jersey City, New Jersey (the “Land Property”) with a balance of $44.7 million (the “Land Note Receivable”). The Land Note Receivable matures in July 2019 and earns interest at an annual rate of 5.85 percent which accrues monthly and is payable at maturity. In March 2018, the Company received a partial prepayment of $3 million. The Land Property is currently an unimproved land parcel which operates as a surface parking facility. Additionally, the Company entered into an agreement to acquire the Land Property, subject to the Company's ability to obtain all necessary development rights and entitlements to develop an apartment building on the land, and other related conditions to ensure that the Company can develop the project. The purchase price is $73 million, subject to adjustment based on the level of development rights obtained for the construction of a multifamily apartment building.  Through February 2016, the Company could not dispose of or distribute certain of its properties, which were originally contributed by certain unrelated common unitholders of the Operating Partnership, without the express written consent of such common unitholders, as applicable, except in a manner which did not result in recognition of any built-in-gain (which may result in an income tax liability) or which reimbursed the appropriate specific common unitholders for the tax consequences of the recognition of such built-in-gains (collectively, the “Property Lock-Ups”). Upon the expiration in February 2016 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 General Partner’s Board of Directors; David S. Mack, director; and Earle I. Mack, a former director), the Robert Martin Group (which includes Robert F. Weinberg, a former director and current member of the General Partner's Advisory Board), and the Cali Group (which includes John R. Cali, a former director and current member of the General Partner's Advisory Board). As of December 31, 2018 , after the effects of tax-free exchanges on certain of the originally contributed properties, either wholly or partially, over time, 79 of the Company’s properties, primarily a portfolio of flex properties in Westchester County, New York with an aggregate carrying value of approximately $ 1.4 billion, are subject to these conditions.

Tenant Leases

Tenant Leases	12 Months Ended
	Dec. 31, 2018
Leases [Line Items]
Tenant Leases	13. TENANT LEASES  The Properties are leased to tenants under operating leases with various expiration dates through 2036 . 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 December 31, 2018 are as follows (dollars in thousands) :     Year Amount  2019 $ 314,708  2020 306,559  2021 284,120  2022 258,076  2023 220,533  2024 and thereafter 923,061   Total $ 2,307,057      Multi-family rental property residential leases are excluded from the above table as they generally expire within one year.
Mack-Cali Realty LP [Member]
Leases [Line Items]
Tenant Leases	13. TENANT LEASES  The Properties are leased to tenants under operating leases with various expiration dates through 2036 . 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 December 31, 2018 are as follows (dollars in thousands) :     Year Amount  2019 $ 314,708  2020 306,559  2021 284,120  2022 258,076  2023 220,533  2024 and thereafter 923,061   Total $ 2,307,057      Multi-family rental property residential leases are excluded from the above table as they generally expire within one year.

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interests	12 Months Ended
	Dec. 31, 2018
Redeemable Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interests	14. REDEEMABLE NONCONTROLLING INTERESTS  The Company evaluates the terms of the partnership units issued in accordance with the FASB’s Distinguishing Liabilities from Equity guidance. Units which embody an unconditional obligation requiring the Company to redeem the units for cash after a specified or determinable date (or dates) or upon the occurrence of an event that is not solely within the control of the issuer are determined to be contingently redeemable under this guidance and are included as Redeemable noncontrolling interests and classified within the mezzanine section between Total liabilities and Stockholders’ equity on the Company’s Consolidated Balance Sheets. Convertible units for which the Company has the option to settle redemption amounts in cash or Common Stock are included in the caption Noncontrolling interests in subsidiaries within the equity section on the Company’s Consolidated Balance Sheet.  Rockpoint Transaction On February 27, 2017, the Company, RRT, the Company’s wholly-owned subsidiary through which the Company conducts its multi-family residential real estate operations, Roseland Residential, L.P. (“RRLP”), the operating partnership through which RRT conducts all of its operations, and certain other affiliates of the Company entered into an equity investment agreement (the “Investment Agreement”) with Rockpoint Group, L.L.C. and certain of its affiliates (collectively, “Rockpoint”). The Investment Agreement provides for multiple equity investments by Rockpoint in RRLP from time to time for up to an aggregate of $300 million of equity units of limited partnership interests of RRLP (the “Rockpoint Units”). The initial closing under the Investment Agreement occurred on March 10, 2017 for $150 million of Rockpoint Units and the parties agreed that the Company's contributed equity value, (“RRT Contributed Equity Value”), was $1.23 billion at closing. Additional closings of Rockpoint Units to be issued and sold to Rockpoint pursuant to the Investment Agreement may occur from time to time in increments of not less than $10 million per closing, with the balance of the full $300 million by March 1, 2019. During the year ended December 31, 2018 , a total additional amount of $105 million of Rockpoint Units were issued and sold to Rockpoint pursuant to the Investment Agreement.  The Company has a participation right, where prior to March 1, 2022 and following either the full investment of $300 million by Rockpoint or in certain other limited circumstances, the Company may contribute up to $200 million to obtain equity units on substantially the same terms and conditions as the Rockpoint Units to be issued and sold to Rockpoint.  Under the terms of the transaction, the cash flow from operations of RRLP will be distributable to RRT and Rockpoint as follows:  first, to provide a 6% annual return to Rockpoint (and to the Company after it contributes to RRT to obtain equity units, as described above) on its invested capital (“Preferred Base Return”); second, to provide a 6% annual return on the equity value of the properties contributed by it to the partnership (“RRT Base Return”) with 95% of the RRT Base Return to RRT and 5% of the RRT Base Return to Rockpoint; and third, pro rata between Rockpoint (and the Company upon its contribution to obtain equity units) and RRT based on total respective invested capital by Rockpoint and RRT Initial Capital Contribution.  Based on Rockpoint’s $255 million invested capital and RRT’s Initial Capital Contribution, at December 31, 2018 this pro rata distribution would be approximately 17.1% to Rockpoint and 82.9% to RRT.  RRLP’s cash flow from capital events will generally be distributable to RRT and Rockpoint as follows:  first, to Rockpoint (and the Company after it contributes to RRT to obtain equity units) to the extent there is any unpaid, accrued Preferred Base Return; second, as a return of capital to Rockpoint (and the Company after it contributes to RRT to obtain equity units); third, to RRT to the extent there is any unpaid, accrued RRT Base Return (with Rockpoint entitled to 5% of the amounts distributable to RRT); fourth, as a return of capital to RRT based on the equity value of the properties contributed by it to the partnership (with Rockpoint entitled to 5% of the amounts distributable to RRT); fifth, pro rata between Rockpoint (and the Company after it contributes to RRT to obtain equity units) and RRT based on total respective invested capital and contributed equity value until Rockpoint has achieved an 11% internal rate of return; and sixth, to Rockpoint (and to the Company after it contributes to RRT to obtain equity units) based on 50% of its pro rata share described in “fifth” above and the balance to RRT.  In general, RRLP may not sell its properties in a taxable transaction, although it may engage in tax-deferred like-kind exchanges of properties or it may proceed in another manner designed to avoid the recognition of gains for tax purposes.  Beginning March 1, 2022, except in certain limited circumstances as defined in the agreement, either RRT or Rockpoint may cause RRT to redeem (a “Put/Call Event”) all, but not less than all, of Rockpoint’s interest in the Rockpoint Units based on a liquidation value of RRLP to be determined by a third party valuation of the real estate assets and generally based on the capital event waterfall described above. On a Put/Call Event, other than the sale of RRLP, Rockpoint can either demand payment in cash or may elect to convert all, but not less than all, of its investment to common equity in RRLP. As such, the Rockpoint Units contain a substantive redemption feature that is outside of the Company’s control and accordingly, pursuant to ASC 480-1--S99-3A, the Rockpoint Units are classified in mezzanine equity measured based on the estimated future redemption value as of December 31, 2018 . The Company determines the redemption value of these interests by hypothetically liquidating the estimated Net Asset Value (“NAV”) of the RRT real estate portfolio including debt principal through the applicable waterfall provisions of the RRLP partnership agreement. The estimation of NAV includes unobservable inputs that consider assumptions of market participants in pricing the underlying assets of RRLP. For properties under development, the Company applies a discount rate to the estimated future cash flows allocable to the Company during the period under construction and then applies a direct capitalization method to the estimated stabilized cash flows. For operating properties the direct capitalization method is used by applying a capitalization rate to the projected net operating income. Estimated future cash flows used in such analyses are based on the Company’s business plan for each respective property including capital expenditures, management's views of market and economic conditions, and considers items such as current and future rental rates, occupancies and market transactions for comparable properties. The estimated future redemption value of Rockpoint Units is approximately $330 million as of December 31, 2018 .  Preferred Units On February 3, 2017, the Operating Partnership issued 42,800 shares of a new class of 3.5 percent Series A Preferred Limited Partnership Units of the Operating Partnership (the “Series A Units”). The Series A Units were issued to the Company’s partners in the Plaza VIII & IX Associates L.L.C. joint venture that owns a development site adjacent to the Company’s Harborside property in Jersey City, New Jersey as non-cash consideration for their approximate 37.5 percent interest in the joint venture.  Each Series A Unit has a stated value of $1,000 , pays dividends quarterly at an annual rate of 3.5 percent (subject to increase under certain circumstances), is convertible into 28.15 common units of limited partnership interests of the Operating Partnership beginning generally five years from the date of issuance, or an aggregate of up to 1,204,820 common units. The conversion rate was based on a value of $35.52 per common unit. The Series A Units have a liquidation and dividend preference senior to the common units and include customary anti-dilution protections for stock splits and similar events. The Series A Units are redeemable for cash at their stated value beginning five years from the date of issuance at the option of the holder.  On February 28, 2017, the Operating Partnership authorized the issuance of 9,213 shares of a new class of 3.5 percent Series A-1 Preferred Limited Partnership Units of the Operating Partnership (the “Series A-1 Units”). 9,122 Series A-1 Units were issued on February 28, 2017 and an additional 91 Series A-1 Units were issued in April 2017 pursuant to acquiring additional interests in a joint venture that owns Monaco Towers in Jersey City, New Jersey. The Series A-1 Units were issued as non-cash consideration for the partner’s approximate 13.8 percent ownership interest in the joint venture.  Each Series A-1 Unit has a stated value of $1,000 (the “Stated Value”), pays dividends quarterly at an annual rate equal to the greater of (x) 3.5 percent, or (y) the then-effective annual dividend yield on the General Partner’s common stock, and is convertible into 27.936 common units of limited partnership interests of the Operating Partnership beginning generally five years from the date of issuance, or an aggregate of up to 257,375 Common Units. The conversion rate was based on a value of $35.80 per common unit. The Series A-1 Units have a liquidation and dividend preference senior to the Common Units and include customary anti-dilution protections for stock splits and similar events. The Series A-1 Units are redeemable for cash at their stated value beginning five years from the date of issuance at the option of the holder. The Series A-1 Units are pari passu with the 42,800 3.5% Series A Units issued on February 3, 2017.  The following table sets forth the changes in Redeemable noncontrolling interests for the year ended December 31, 2018 (dollars in thousands) :     Series A and Total  A-1 Preferred Rockpoint Redeemable  Units Interests Noncontrolling  In MCRLP in RRT Interests  Balance January 1, 2018 $ 52,324 $ 159,884 $ 212,208  Redeemable Noncontrolling Interests Issued - 105,000 105,000  Net 52,324 264,884 317,208  Income Attributed to Noncontrolling Interests 1,820 12,159 13,979  Distributions (1,820) (12,159) (13,979)  Redemption Value Adjustment - 13,251 13,251  Redeemable noncontrolling interests as of December 31, 2018 $ 52,324 $ 278,135 $ 330,459 
Mack-Cali Realty LP [Member]
Redeemable Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interests	14. REDEEMABLE NONCONTROLLING INTERESTS  The Company evaluates the terms of the partnership units issued in accordance with the FASB’s Distinguishing Liabilities from Equity guidance. Units which embody an unconditional obligation requiring the Company to redeem the units for cash after a specified or determinable date (or dates) or upon the occurrence of an event that is not solely within the control of the issuer are determined to be contingently redeemable under this guidance and are included as Redeemable noncontrolling interests and classified within the mezzanine section between Total liabilities and Stockholders’ equity on the Company’s Consolidated Balance Sheets. Convertible units for which the Company has the option to settle redemption amounts in cash or Common Stock are included in the caption Noncontrolling interests in subsidiaries within the equity section on the Company’s Consolidated Balance Sheet.  Rockpoint Transaction On February 27, 2017, the Company, RRT, the Company’s wholly-owned subsidiary through which the Company conducts its multi-family residential real estate operations, Roseland Residential, L.P. (“RRLP”), the operating partnership through which RRT conducts all of its operations, and certain other affiliates of the Company entered into an equity investment agreement (the “Investment Agreement”) with Rockpoint Group, L.L.C. and certain of its affiliates (collectively, “Rockpoint”). The Investment Agreement provides for multiple equity investments by Rockpoint in RRLP from time to time for up to an aggregate of $300 million of equity units of limited partnership interests of RRLP (the “Rockpoint Units”). The initial closing under the Investment Agreement occurred on March 10, 2017 for $150 million of Rockpoint Units and the parties agreed that the Company's contributed equity value, (“RRT Contributed Equity Value”), was $1.23 billion at closing. Additional closings of Rockpoint Units to be issued and sold to Rockpoint pursuant to the Investment Agreement may occur from time to time in increments of not less than $10 million per closing, with the balance of the full $300 million by March 1, 2019. During the year ended December 31, 2018 , a total additional amount of $105 million of Rockpoint Units were issued and sold to Rockpoint pursuant to the Investment Agreement.  The Company has a participation right, where prior to March 1, 2022 and following either the full investment of $300 million by Rockpoint or in certain other limited circumstances, the Company may contribute up to $200 million to obtain equity units on substantially the same terms and conditions as the Rockpoint Units to be issued and sold to Rockpoint.  Under the terms of the transaction, the cash flow from operations of RRLP will be distributable to RRT and Rockpoint as follows:  first, to provide a 6% annual return to Rockpoint (and to the Company after it contributes to RRT to obtain equity units, as described above) on its invested capital (“Preferred Base Return”); second, to provide a 6% annual return on the equity value of the properties contributed by it to the partnership (“RRT Base Return”) with 95% of the RRT Base Return to RRT and 5% of the RRT Base Return to Rockpoint; and third, pro rata between Rockpoint (and the Company upon its contribution to obtain equity units) and RRT based on total respective invested capital by Rockpoint and RRT Initial Capital Contribution.  Based on Rockpoint’s $255 million invested capital and RRT’s Initial Capital Contribution, at December 31, 2018 this pro rata distribution would be approximately 17.1% to Rockpoint and 82.9% to RRT.  RRLP’s cash flow from capital events will generally be distributable to RRT and Rockpoint as follows:  first, to Rockpoint (and the Company after it contributes to RRT to obtain equity units) to the extent there is any unpaid, accrued Preferred Base Return; second, as a return of capital to Rockpoint (and the Company after it contributes to RRT to obtain equity units); third, to RRT to the extent there is any unpaid, accrued RRT Base Return (with Rockpoint entitled to 5% of the amounts distributable to RRT); fourth, as a return of capital to RRT based on the equity value of the properties contributed by it to the partnership (with Rockpoint entitled to 5% of the amounts distributable to RRT); fifth, pro rata between Rockpoint (and the Company after it contributes to RRT to obtain equity units) and RRT based on total respective invested capital and contributed equity value until Rockpoint has achieved an 11% internal rate of return; and sixth, to Rockpoint (and to the Company after it contributes to RRT to obtain equity units) based on 50% of its pro rata share described in “fifth” above and the balance to RRT.  In general, RRLP may not sell its properties in a taxable transaction, although it may engage in tax-deferred like-kind exchanges of properties or it may proceed in another manner designed to avoid the recognition of gains for tax purposes.  Beginning March 1, 2022, except in certain limited circumstances as defined in the agreement, either RRT or Rockpoint may cause RRT to redeem (a “Put/Call Event”) all, but not less than all, of Rockpoint’s interest in the Rockpoint Units based on a liquidation value of RRLP to be determined by a third party valuation of the real estate assets and generally based on the capital event waterfall described above. On a Put/Call Event, other than the sale of RRLP, Rockpoint can either demand payment in cash or may elect to convert all, but not less than all, of its investment to common equity in RRLP. As such, the Rockpoint Units contain a substantive redemption feature that is outside of the Company’s control and accordingly, pursuant to ASC 480-1--S99-3A, the Rockpoint Units are classified in mezzanine equity measured based on the estimated future redemption value as of December 31, 2018 . The Company determines the redemption value of these interests by hypothetically liquidating the estimated Net Asset Value (“NAV”) of the RRT real estate portfolio including debt principal through the applicable waterfall provisions of the RRLP partnership agreement. The estimation of NAV includes unobservable inputs that consider assumptions of market participants in pricing the underlying assets of RRLP. For properties under development, the Company applies a discount rate to the estimated future cash flows allocable to the Company during the period under construction and then applies a direct capitalization method to the estimated stabilized cash flows. For operating properties the direct capitalization method is used by applying a capitalization rate to the projected net operating income. Estimated future cash flows used in such analyses are based on the Company’s business plan for each respective property including capital expenditures, management's views of market and economic conditions, and considers items such as current and future rental rates, occupancies and market transactions for comparable properties. The estimated future redemption value of Rockpoint Units is approximately $330 million as of December 31, 2018 .  Preferred Units On February 3, 2017, the Operating Partnership issued 42,800 shares of a new class of 3.5 percent Series A Preferred Limited Partnership Units of the Operating Partnership (the “Series A Units”). The Series A Units were issued to the Company’s partners in the Plaza VIII & IX Associates L.L.C. joint venture that owns a development site adjacent to the Company’s Harborside property in Jersey City, New Jersey as non-cash consideration for their approximate 37.5 percent interest in the joint venture.  Each Series A Unit has a stated value of $1,000 , pays dividends quarterly at an annual rate of 3.5 percent (subject to increase under certain circumstances), is convertible into 28.15 common units of limited partnership interests of the Operating Partnership beginning generally five years from the date of issuance, or an aggregate of up to 1,204,820 common units. The conversion rate was based on a value of $35.52 per common unit. The Series A Units have a liquidation and dividend preference senior to the common units and include customary anti-dilution protections for stock splits and similar events. The Series A Units are redeemable for cash at their stated value beginning five years from the date of issuance at the option of the holder.  On February 28, 2017, the Operating Partnership authorized the issuance of 9,213 shares of a new class of 3.5 percent Series A-1 Preferred Limited Partnership Units of the Operating Partnership (the “Series A-1 Units”). 9,122 Series A-1 Units were issued on February 28, 2017 and an additional 91 Series A-1 Units were issued in April 2017 pursuant to acquiring additional interests in a joint venture that owns Monaco Towers in Jersey City, New Jersey. The Series A-1 Units were issued as non-cash consideration for the partner’s approximate 13.8 percent ownership interest in the joint venture.  Each Series A-1 Unit has a stated value of $1,000 (the “Stated Value”), pays dividends quarterly at an annual rate equal to the greater of (x) 3.5 percent, or (y) the then-effective annual dividend yield on the General Partner’s common stock, and is convertible into 27.936 common units of limited partnership interests of the Operating Partnership beginning generally five years from the date of issuance, or an aggregate of up to 257,375 Common Units. The conversion rate was based on a value of $35.80 per common unit. The Series A-1 Units have a liquidation and dividend preference senior to the Common Units and include customary anti-dilution protections for stock splits and similar events. The Series A-1 Units are redeemable for cash at their stated value beginning five years from the date of issuance at the option of the holder. The Series A-1 Units are pari passu with the 42,800 3.5% Series A Units issued on February 3, 2017.  The following table sets forth the changes in Redeemable noncontrolling interests for the year ended December 31, 2018 (dollars in thousands) :     Series A and Total  A-1 Preferred Rockpoint Redeemable  Units Interests Noncontrolling  In MCRLP in RRT Interests  Balance January 1, 2018 $ 52,324 $ 159,884 $ 212,208  Redeemable Noncontrolling Interests Issued - 105,000 105,000  Net 52,324 264,884 317,208  Income Attributed to Noncontrolling Interests 1,820 12,159 13,979  Distributions (1,820) (12,159) (13,979)  Redemption Value Adjustment - 13,251 13,251  Redeemable noncontrolling interests as of December 31, 2018 $ 52,324 $ 278,135 $ 330,459 

Mack-Cali Realty Corporation St

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital	12 Months Ended
	Dec. 31, 2018
Stockolders Equity [Line Items]
Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital	15. MACK-CALI REALTY CORPORATION STOCKHOLDERS’ EQUITY AND MACK-CALI REALTY, L.P.’S PARTNERS’ CAPITAL  To maintain its qualification as a REIT, not more than 50 percent in value of the outstanding shares of the General Partner may be owned, directly or indirectly, by five or fewer individuals at any time during the last half of any taxable year of the General Partner, other than its initial taxable year (defined to include certain entities), applying certain constructive ownership rules. To help ensure that the General Partner will not fail this test, the General Partner’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 General Partner 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.  Partners’ Capital in the accompanying consolidated financial statements relates to (a) General Partners’ capital consisting of common units in the Operating Partnership held by the General Partner, and (b) Limited Partners’ capital consisting of common units and LTIP units held by the limited partners. See Note 16: Noncontrolling Interests in Subsidiaries.  Any transactions resulting in the issuance of additional common and preferred stock of the General Partner result in a corresponding issuance by the Operating Partnership of an equivalent amount of common and preferred units to the General Partner.  SHARE/UNIT REPURCHASE PROGRAM In September 2012 , the Board of Directors of the General Partner renewed and authorized an increase to the General Partner’s repurchase program (“Repurchase Program”). The General Partner 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. As of December 31, 2018 , the General Partner has repurchased 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. Concurrent with these repurchases, the General Partner sold to the Operating Partnership common units for approximately $11 million. DIVIDEND REINVESTMENT AND STOCK PURCHASE PLAN The General Partner has a Dividend Reinvestment and Stock Purchase Plan (the “DRIP”) which commenced in March 1999 under which approximately 5.5 million shares of the General Partner’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 General Partner’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 General Partner’s common stock reserved for issuance under the DRIP.  STOCK OPTION PLANS In May 2013, the General Partner established the 2013 Incentive Stock Plan (the “2013 Plan”) under which a total of 4,600,000 shares have been reserved for issuance.  On June 5, 2015, in connection with employment agreements entered into with each of Messrs. Rudin and DeMarco (together, the “Executive Employment Agreements”), the Company granted options to purchase a total of 800,000 shares of the General Partner’s common stock, exercisable for a period of ten years with an exercise price equal to the closing price of the General Partner’s common stock on the grant date of $17.31 per share, with 400,000 of such options vesting in three equal annual installments commencing on the first anniversary of the grant date (“Time Vesting Options”) and fully vesting on June 5, 2018, and 400,000 of such options vesting if the General Partner’s common stock trades at or above $25.00 per share for 30 consecutive trading days while the executive is employed (“Price Vesting Options”), or on or before June 30, 2019, subject to certain conditions. The Price Vesting Options vested on July 5, 2016 on account of the price vesting condition being achieved.  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, 2016 805,000 $ 17.33 $ 4,843  Lapsed or Cancelled (5,000) 21.25 -  Outstanding at December 31, 2016 ( $17.31 ) 800,000 $ 17.31 9,368  Granted, Lapsed or Cancelled - -  Outstanding at December 31, 2017 ($17.31) 800,000 $ 17.31 3,400  Granted, Lapsed or Cancelled - -  Outstanding at December 31, 2018 ($17.31) 800,000 $ 17.31 $ 1,824  Options exercisable at December 31, 2018 800,000  Available for grant at December 31, 2018 1,580,869  There were no stock options exercised under any stock option plans for the year s ended December 31, 2018 , 2017 and 2016 . The Company has a policy of issuing new shares to satisfy stock option exercises.  As of December 31, 2018 and 2017 , the stock options outstanding had a weighted average remaining contractual life of approximately 6.4 years and 7.4 years, respectively.  The Company recognized stock options expense of $ 193,000 , $ 464,000 and $ 1,407,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively.  RESTRICTED STOCK AWARDS The Company has issued stock awards (“Restricted Stock Awards”) to officers, certain other employees and non-employee members of the Board of Directors of the General Partner, which allow the holders to each receive a certain amount of shares of the General Partner’s common stock generally over a one to seven -year vesting period, of which 67,289 unvested shares were legally outstanding at December 31, 2018 . Vesting of the Restricted Stock Awards issued to executive officers and certain other employees is based on time and service.  On June 5, 2015, in connection with the Executive Employment Agreements, the Company granted a total of 37,550.54 Restricted Stock Awards, which were valued in accordance with ASC 718 – Stock Compensation, at their fair value. These awards vested equally over a three -year period on each annual anniversary date of the grant date.  All currently outstanding and unvested Restricted Stock Awards provided to the officers, certain other employees, and members of the Board of Directors of the General Partner were issued under the 2013 Plan.  Information regarding the Restricted Stock Awards grant activity is summarized below:    Weighted-Average  Grant – Date  Shares Fair Value  Outstanding at January 1, 2016 136,220 $ 19.36  Granted 74,622 23.79  Vested (61,654) 18.94  Forfeited (3,910) 21.58  Outstanding at December 31, 2016 145,278 $ 21.76  Granted 59,985 27.00  Vested (95,009) 20.73  Forfeited (1,936) 25.83  Outstanding at December 31, 2017 108,318 $ 25.49  Granted 40,185 20.16  Vested (72,502) 25.33  Forfeited (8,712) 25.83  Outstanding at December 31, 2018 67,289 $ 22.43 As of December 31, 2018 , the Company had $0.5 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 0.5 years.  PERFORMANCE SHARE UNITS On June 5, 2015, in connection with the Executive Employment Agreements, the Company granted a total of 112,651.64 performance share units (“PSUs”) which was to vest from 0 to 150 percent of the number of PSUs granted based on the Company’s total shareholder return relative to a peer group of equity office REITs over a three -year performance period starting from the grant date, each PSU evidencing the right to receive a share of the General Partner’s common stock upon vesting. The PSUs were also entitled to the payment of dividend equivalents in respect of vested PSUs in the form of additional PSUs. The PSUs were valued in accordance with ASC 718, Compensation - Stock Compensation, at their fair value on the grant date, utilizing a Monte-Carlo simulation to estimate the probability of the vesting conditions being satisfied.  The PSUs vested at 100 percent on June 5, 2018 based on the calculation of the achievement of the Company’s total shareholder return, for which shares of the General Partner’s common stock were issued under the 2013 Plan.  As of December 31, 2018 , the Company had no unrecognized compensation cost as there are no unvested PSUs outstanding under the Company’s stock compensation plans.  LONG-TERM INCENTIVE PLAN AWARDS On March 8, 2016, the Company granted Long-Term Incentive Plan (“LTIP”) awards to senior management of the Company, including the General Partner’s executive officers (the “2016 LTIP Awards”). All of the 2016 LTIP Awards were in the form of units in the Operating Partnership (“LTIP Units”) and constitute awards under the 2013 Plan. For Messrs. Rudin, DeMarco and Tycher, approximately 25 percent of the target 2016 LTIP Award was in the form of a time-based award that vests after three years on March 8, 2019 (the “2016 TBV LTIP Units”), and the remaining approximately 75 percent of the target 2016 LTIP Award was in the form of a performance-based award under a new Outperformance Plan (the “2016 OPP”) adopted by the General Partner’s Board of Directors consisting of a multi-year, performance-based equity compensation plan and related forms of award agreement (the “2016 PBV LTIP Units”). For all other executive officers, approximately 40 percent of the target 2016 LTIP Award was in the form of 2016 TBV LTIP Units and the remaining approximately 60 percent of the target 2016 LTIP Award was in the form of 2016 PBV LTIP Units.  The 2016 OPP was designed to align the interests of senior management to relative and absolute performance of the Company over a three -year performance period from March 8, 2016 through March 7, 2019. Participants in the 2016 OPP will only earn the full awards if, over the three -year performance period, the Company achieves a 50 percent absolute total stockholder return (“TSR”) and if the Company is in the 75th percentile of performance versus the NAREIT Office Index.  On April 4, 2017, the Company granted LTIP awards to senior management of the Company, including the General Partner’s executive officers (the “2017 LTIP Awards”). All of the 2017 LTIP Awards were in the form of LTIP Units and constitute awards under the 2013 Plan. For Messrs. DeMarco, Tycher and Rudin, approximately twenty-five percent ( 25% ) of the 2017 LTIP Award was in the form of a time-based award that vests after three years on April 4, 2020 (the “2017 TBV LTIP Units”), and the remaining approximately seventy-five percent ( 75% ) of the 2017 LTIP Award was in the form of a performance-based award under the Company’s Outperformance Plan (the “2017 OPP”) adopted by the General Partner’s Board of Directors, consisting of a multi-year, performance-based equity compensation plan and related forms of award agreement (the “2017 PBV LTIP Units”). For all other executive officers, approximately forty percent ( 40% ) of the 2017 LTIP Award was in the form of 2017 TBV LTIP Units and the remaining approximately sixty percent ( 60% ) of the 2017 LTIP Award was in the form of 2017 PBV LTIP Units.  The 2017 OPP was designed to align the interests of senior management to relative and absolute performance of the Company over a three-year performance period from April 4, 2017 through April 3, 2020. Participants in the 2017 OPP will only earn the full awards if, over the three -year performance period, the Company achieves a thirty-six percent ( 36% ) absolute TSR and if the Company is in the 75th percentile of performance as compared to the NAREIT office index.  On April 20, 2018, the Company granted LTIP awards to senior management of the Company, including the General Partner’s executive officers (the “2018 LTIP Awards”). All of the 2018 LTIP Awards were in the form of LTIP Units and constitute awards under the 2013 Plan. For Messrs. DeMarco and Tycher, approximately twenty-five percent ( 25% ) of the grant date fair value of the 2018 LTIP Award was in the form of a time-based award that vests after three years on April 20, 2021 (the “2018 TBV LTIP Units”), and the remaining approximately seventy-five percent ( 75% ) of the grant date fair value of the 2018 LTIP Award was in the form of a performance-based award under the Company’s Outperformance Plan (the “2018 OPP”) adopted by the General Partner’s Board of Directors, consisting of a multi-year, performance-based equity compensation plan and related forms of award agreement (the “2018 PBV LTIP Units”). For all other executive officers, approximately fifty percent ( 50% ) of the grant date fair value of the 2018 LTIP Award was in the form of 2018 TBV LTIP Units and the remaining approximately fifty percent ( 50% ) of the grant date fair value of the 2018 LTIP Award was in the form of 2018 PBV LTIP Units.  The 2018 OPP was designed to align the interests of senior management to relative and absolute performance of the Company over a three-year performance period from April 20, 2018 through April 19, 2021. Participants in the 2018 OPP will only earn the full awards if, over the three -year performance period, the Company achieves a thirty-six percent ( 36% ) absolute TSR and if the Company’s TSR is in the 75th percentile of performance as compared to the office REITs in the NAREIT index.  LTIP Units will remain subject to forfeiture depending on the extent that the 2016 LTIP Awards, 2017 LTIP Awards and 2018 LTIP Awards vest. The number of LTIP Units to be issued initially to recipients of the 2016 PBV LTIP Awards, 2017 PBV LTIP Awards and 2018 PBV LTIP Awards is the maximum number of LTIP Units that may be earned under the awards. The number of LTIP Units that actually vest for each award recipient will be determined at the end of the performance measurement period. TSR for the Company and for the Index over the three-year measurement period and other circumstances will determine how many LTIP Units vest for each recipient; if they are fewer than the number issued initially, the balance will be forfeited as of the performance measurement date.  Prior to vesting, recipients of LTIP Units will be entitled to receive per unit distributions equal to one-tenth ( 10 percent) of the regular quarterly distributions payable on a common unit of limited partnership interest in the Operating Partnership (a “common unit”), but will not be entitled to receive any special distributions. Distributions with respect to the other nine-tenths ( 90 percent) of regular quarterly distributions payable on a common unit will accrue but shall only become payable upon vesting of the LTIP Unit. After vesting of the 2016 TBV LTIP Units, 2017 TBV LTIP Units and 2018 LTIP TBV Units or the end of the measurement period for the 2016 PBV LTIP Units, 2017 PBV LTIP Units and 2018 LTIP PBV Units, the number of LTIP Units, both vested and unvested, will be entitled to receive distributions in an amount per unit equal to distributions, both regular and special, payable on a common unit.  As a result of certain executive management and other personnel changes during the year ended December 31, 2018 , the former employees forfeited and cancelled 189,273 2016 LTIP Awards, 105,443 2017 LTIP Awards and 38,015 2018 LTIP Awards, and the Company accelerated the vesting of 22,215 2016 LTIP Awards and 32,849 2017 LTIP Awards. As of December 31, 2018 , a total of 332,302 2016 PBV LTIP Units, 108,764 2016 TBV LTIP Units, 370,509 2017 PBV LTIP Units, 69,522 2017 TBV LTIP Units, 629,252 2018 PBV LTIP Units and 196,757 2018 TBV LTIP Units, net of LTIP Units forfeited and cancelled resulting from executive management and other personnel changes, were outstanding. The LTIP Units were valued in accordance with ASC 718 – Stock Compensation, at their fair value. The Company has reserved shares of common stock under the 2013 Plan for issuance upon vesting and conversion of the LTIP Units in accordance with their terms and conditions.  As of December 31, 2018 , the Company had $11.2 million of total unrecognized compensation cost related to unvested LTIP awards granted under the Company’s stock compensation plans. That cost is expected to be recognized over a weighted average period of 2.4 years.  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 year s ended December 31, 2018 , 2017 and 2016 , 26,620 , 19,728 and 14,274 deferred stock units were earned, respectively. As of December 31, 2018 and 2017 , there were 236,383 and 210,738 deferred stock units outstanding, respectively.  EARNINGS PER SHARE/UNIT Basic EPS or EPU excludes dilution and is computed by dividing net income available to common shareholders or unitholders by the weighted average number of shares or units outstanding for the period. Diluted EPS or EPU 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 years ended December 31, 2018 , 2017 and 2016 in accordance with ASC 260, Earnings Per Share (dollars in thousands, except per share amounts) :  Mack-Cali Realty Corporation:    Year Ended December 31,  Computation of Basic EPS 2018 2017 2016  Net income $ 106,401 $ 33,718 $ 130,294  Add: Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Add (deduct): Noncontrolling interest in Operating Partnership (9,527) (2,711) (13,721)  Deduct: Redeemable noncontrolling interest (13,979) (8,840) -  Deduct: Redemption value adjustment of redeemable noncontrolling  interests attributable to common shareholders (11,425) (17,951) -  Net income available to common shareholders for basic earnings per share $ 72,686 $ 5,234 $ 117,224   Weighted average common shares 90,388 90,005 89,746   Basic EPS :  Net income available to common shareholders $ 0.80 $ 0.06 $ 1.31         Year Ended December 31,  Computation of Diluted EPS 2018 2017 2016  Net income available to common shareholders for basic earnings per share $ 72,686 $ 5,234 $ 117,224  Add (deduct): Noncontrolling interest in Operating Partnership 9,527 2,711 13,721  Deduct: Redemption value adjustment of redeemable noncontrolling  interests attributable to the Operating Partnership unitholders (1,296) (2,074) -  Net income available for diluted earnings per share $ 80,917 $ 5,871 $ 130,945   Weighted average common shares 100,724 100,703 100,498   Diluted EPS :  Net income available to common shareholders $ 0.80 $ 0.06 $ 1.30   The following schedule reconciles the weighted average shares used in the basic EPS calculation to the shares used in the diluted EPS calculation (in thousands):   Year Ended December 31,  2018 2017 2016  Basic EPS shares 90,388 90,005 89,746  Add: Operating Partnership – common and vested LTIP units 10,246 10,405 10,499  Restricted Stock Awards - 40 43  Stock Options 90 253 210  Diluted EPS Shares 100,724 100,703 100,498  Contingently issuable shares under the PSU Awards were excluded from the denominator in 2017 and 2016 because the criteria had not been met for the periods. Contingently issuable shares under Restricted Stock Awards were excluded from the denominator in 2018 as such securities were anti-dilutive during the period. Also not included in the computations of diluted EPS were the unvested LTIP Units as such securities were anti-dilutive during all periods presented. Unvested restricted stock outstanding as of December 31, 2018 , 2017 and 2016 were 67,289 , 95,801 and 120,245 shares, respectively.  Dividends declared per common share for the years ended December 31, 2018 , 2017 and 2016 was $0.80 , $0.75 and $0.60 per share, respectively.  Mack-Cali Realty, L.P.:     Year Ended December 31,  Computation of Basic EPU 2018 2017 2016  Net income $ 106,401 $ 33,718 $ 130,294  Add: Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Deduct: Redeemable noncontrolling interest (13,979) (8,840) -  Deduct: Redemption value adjustment of redeemable noncontrolling interests (12,721) (20,025) -  Net income available to common unitholders for basic earnings per unit $ 80,917 $ 5,871 $ 130,945   Weighted average common units 100,634 100,410 100,245   Basic EPU :  Net income available to common unitholders for basic earnings per unit $ 0.80 $ 0.06 $ 1.31    Year Ended December 31,  Computation of Diluted EPU 2018 2017 2016  Net income available to common unitholders for diluted earnings per unit $ 80,917 $ 5,871 $ 130,945   Weighted average common unit 100,724 100,703 100,498   Diluted EPU :  Net income available to common unitholders $ 0.80 $ 0.06 $ 1.30  The following schedule reconciles the weighted average units used in the basic EPU calculation to the units used in the diluted EPU calculation (in thousands) :    Year Ended December 31,  2018 2017 2016  Basic EPU units 100,634 100,410 100,245  Add: Restricted Stock Awards - 40 43  Stock Options 90 253 210  Diluted EPU Units 100,724 100,703 100,498  Contingently issuable shares under the PSU Awards were excluded from the denominator in 2017 and 2016 because the criteria had not been met for the periods. Contingently issuable shares under Restricted Stock Awards were excluded from the denominator in 2018 as such securities were anti-dilutive during the period. Also not included in the computations of diluted EPU were the unvested LTIP Units as such securities were anti-dilutive during all periods presented. Unvested restricted stock outstanding as of December 31, 2018 , 2017 and 2016 were 67,289 , 95,801 and 120,245 shares, respectively.  Distributions declared per common unit for the years ended December 31, 2018 , 2017 and 2016 was $ 0.80 , $0.75 and $0.60 per unit, respectively.
Mack-Cali Realty LP [Member]
Stockolders Equity [Line Items]
Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital	15. MACK-CALI REALTY CORPORATION STOCKHOLDERS’ EQUITY AND MACK-CALI REALTY, L.P.’S PARTNERS’ CAPITAL  To maintain its qualification as a REIT, not more than 50 percent in value of the outstanding shares of the General Partner may be owned, directly or indirectly, by five or fewer individuals at any time during the last half of any taxable year of the General Partner, other than its initial taxable year (defined to include certain entities), applying certain constructive ownership rules. To help ensure that the General Partner will not fail this test, the General Partner’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 General Partner 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.  Partners’ Capital in the accompanying consolidated financial statements relates to (a) General Partners’ capital consisting of common units in the Operating Partnership held by the General Partner, and (b) Limited Partners’ capital consisting of common units and LTIP units held by the limited partners. See Note 16: Noncontrolling Interests in Subsidiaries.  Any transactions resulting in the issuance of additional common and preferred stock of the General Partner result in a corresponding issuance by the Operating Partnership of an equivalent amount of common and preferred units to the General Partner.  SHARE/UNIT REPURCHASE PROGRAM In September 2012 , the Board of Directors of the General Partner renewed and authorized an increase to the General Partner’s repurchase program (“Repurchase Program”). The General Partner 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. As of December 31, 2018 , the General Partner has repurchased 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. Concurrent with these repurchases, the General Partner sold to the Operating Partnership common units for approximately $11 million. DIVIDEND REINVESTMENT AND STOCK PURCHASE PLAN The General Partner has a Dividend Reinvestment and Stock Purchase Plan (the “DRIP”) which commenced in March 1999 under which approximately 5.5 million shares of the General Partner’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 General Partner’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 General Partner’s common stock reserved for issuance under the DRIP.  STOCK OPTION PLANS In May 2013, the General Partner established the 2013 Incentive Stock Plan (the “2013 Plan”) under which a total of 4,600,000 shares have been reserved for issuance.  On June 5, 2015, in connection with employment agreements entered into with each of Messrs. Rudin and DeMarco (together, the “Executive Employment Agreements”), the Company granted options to purchase a total of 800,000 shares of the General Partner’s common stock, exercisable for a period of ten years with an exercise price equal to the closing price of the General Partner’s common stock on the grant date of $17.31 per share, with 400,000 of such options vesting in three equal annual installments commencing on the first anniversary of the grant date (“Time Vesting Options”) and fully vesting on June 5, 2018, and 400,000 of such options vesting if the General Partner’s common stock trades at or above $25.00 per share for 30 consecutive trading days while the executive is employed (“Price Vesting Options”), or on or before June 30, 2019, subject to certain conditions. The Price Vesting Options vested on July 5, 2016 on account of the price vesting condition being achieved.  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, 2016 805,000 $ 17.33 $ 4,843  Lapsed or Cancelled (5,000) 21.25 -  Outstanding at December 31, 2016 ( $17.31 ) 800,000 $ 17.31 9,368  Granted, Lapsed or Cancelled - -  Outstanding at December 31, 2017 ($17.31) 800,000 $ 17.31 3,400  Granted, Lapsed or Cancelled - -  Outstanding at December 31, 2018 ($17.31) 800,000 $ 17.31 $ 1,824  Options exercisable at December 31, 2018 800,000  Available for grant at December 31, 2018 1,580,869  There were no stock options exercised under any stock option plans for the year s ended December 31, 2018 , 2017 and 2016 . The Company has a policy of issuing new shares to satisfy stock option exercises.  As of December 31, 2018 and 2017 , the stock options outstanding had a weighted average remaining contractual life of approximately 6.4 years and 7.4 years, respectively.  The Company recognized stock options expense of $ 193,000 , $ 464,000 and $ 1,407,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively.  RESTRICTED STOCK AWARDS The Company has issued stock awards (“Restricted Stock Awards”) to officers, certain other employees and non-employee members of the Board of Directors of the General Partner, which allow the holders to each receive a certain amount of shares of the General Partner’s common stock generally over a one to seven -year vesting period, of which 67,289 unvested shares were legally outstanding at December 31, 2018 . Vesting of the Restricted Stock Awards issued to executive officers and certain other employees is based on time and service.  On June 5, 2015, in connection with the Executive Employment Agreements, the Company granted a total of 37,550.54 Restricted Stock Awards, which were valued in accordance with ASC 718 – Stock Compensation, at their fair value. These awards vested equally over a three -year period on each annual anniversary date of the grant date.  All currently outstanding and unvested Restricted Stock Awards provided to the officers, certain other employees, and members of the Board of Directors of the General Partner were issued under the 2013 Plan.  Information regarding the Restricted Stock Awards grant activity is summarized below:    Weighted-Average  Grant – Date  Shares Fair Value  Outstanding at January 1, 2016 136,220 $ 19.36  Granted 74,622 23.79  Vested (61,654) 18.94  Forfeited (3,910) 21.58  Outstanding at December 31, 2016 145,278 $ 21.76  Granted 59,985 27.00  Vested (95,009) 20.73  Forfeited (1,936) 25.83  Outstanding at December 31, 2017 108,318 $ 25.49  Granted 40,185 20.16  Vested (72,502) 25.33  Forfeited (8,712) 25.83  Outstanding at December 31, 2018 67,289 $ 22.43 As of December 31, 2018 , the Company had $0.5 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 0.5 years.  PERFORMANCE SHARE UNITS On June 5, 2015, in connection with the Executive Employment Agreements, the Company granted a total of 112,651.64 performance share units (“PSUs”) which was to vest from 0 to 150 percent of the number of PSUs granted based on the Company’s total shareholder return relative to a peer group of equity office REITs over a three -year performance period starting from the grant date, each PSU evidencing the right to receive a share of the General Partner’s common stock upon vesting. The PSUs were also entitled to the payment of dividend equivalents in respect of vested PSUs in the form of additional PSUs. The PSUs were valued in accordance with ASC 718, Compensation - Stock Compensation, at their fair value on the grant date, utilizing a Monte-Carlo simulation to estimate the probability of the vesting conditions being satisfied.  The PSUs vested at 100 percent on June 5, 2018 based on the calculation of the achievement of the Company’s total shareholder return, for which shares of the General Partner’s common stock were issued under the 2013 Plan.  As of December 31, 2018 , the Company had no unrecognized compensation cost as there are no unvested PSUs outstanding under the Company’s stock compensation plans.  LONG-TERM INCENTIVE PLAN AWARDS On March 8, 2016, the Company granted Long-Term Incentive Plan (“LTIP”) awards to senior management of the Company, including the General Partner’s executive officers (the “2016 LTIP Awards”). All of the 2016 LTIP Awards were in the form of units in the Operating Partnership (“LTIP Units”) and constitute awards under the 2013 Plan. For Messrs. Rudin, DeMarco and Tycher, approximately 25 percent of the target 2016 LTIP Award was in the form of a time-based award that vests after three years on March 8, 2019 (the “2016 TBV LTIP Units”), and the remaining approximately 75 percent of the target 2016 LTIP Award was in the form of a performance-based award under a new Outperformance Plan (the “2016 OPP”) adopted by the General Partner’s Board of Directors consisting of a multi-year, performance-based equity compensation plan and related forms of award agreement (the “2016 PBV LTIP Units”). For all other executive officers, approximately 40 percent of the target 2016 LTIP Award was in the form of 2016 TBV LTIP Units and the remaining approximately 60 percent of the target 2016 LTIP Award was in the form of 2016 PBV LTIP Units.  The 2016 OPP was designed to align the interests of senior management to relative and absolute performance of the Company over a three -year performance period from March 8, 2016 through March 7, 2019. Participants in the 2016 OPP will only earn the full awards if, over the three -year performance period, the Company achieves a 50 percent absolute total stockholder return (“TSR”) and if the Company is in the 75th percentile of performance versus the NAREIT Office Index.  On April 4, 2017, the Company granted LTIP awards to senior management of the Company, including the General Partner’s executive officers (the “2017 LTIP Awards”). All of the 2017 LTIP Awards were in the form of LTIP Units and constitute awards under the 2013 Plan. For Messrs. DeMarco, Tycher and Rudin, approximately twenty-five percent ( 25% ) of the 2017 LTIP Award was in the form of a time-based award that vests after three years on April 4, 2020 (the “2017 TBV LTIP Units”), and the remaining approximately seventy-five percent ( 75% ) of the 2017 LTIP Award was in the form of a performance-based award under the Company’s Outperformance Plan (the “2017 OPP”) adopted by the General Partner’s Board of Directors, consisting of a multi-year, performance-based equity compensation plan and related forms of award agreement (the “2017 PBV LTIP Units”). For all other executive officers, approximately forty percent ( 40% ) of the 2017 LTIP Award was in the form of 2017 TBV LTIP Units and the remaining approximately sixty percent ( 60% ) of the 2017 LTIP Award was in the form of 2017 PBV LTIP Units.  The 2017 OPP was designed to align the interests of senior management to relative and absolute performance of the Company over a three-year performance period from April 4, 2017 through April 3, 2020. Participants in the 2017 OPP will only earn the full awards if, over the three -year performance period, the Company achieves a thirty-six percent ( 36% ) absolute TSR and if the Company is in the 75th percentile of performance as compared to the NAREIT office index.  On April 20, 2018, the Company granted LTIP awards to senior management of the Company, including the General Partner’s executive officers (the “2018 LTIP Awards”). All of the 2018 LTIP Awards were in the form of LTIP Units and constitute awards under the 2013 Plan. For Messrs. DeMarco and Tycher, approximately twenty-five percent ( 25% ) of the grant date fair value of the 2018 LTIP Award was in the form of a time-based award that vests after three years on April 20, 2021 (the “2018 TBV LTIP Units”), and the remaining approximately seventy-five percent ( 75% ) of the grant date fair value of the 2018 LTIP Award was in the form of a performance-based award under the Company’s Outperformance Plan (the “2018 OPP”) adopted by the General Partner’s Board of Directors, consisting of a multi-year, performance-based equity compensation plan and related forms of award agreement (the “2018 PBV LTIP Units”). For all other executive officers, approximately fifty percent ( 50% ) of the grant date fair value of the 2018 LTIP Award was in the form of 2018 TBV LTIP Units and the remaining approximately fifty percent ( 50% ) of the grant date fair value of the 2018 LTIP Award was in the form of 2018 PBV LTIP Units.  The 2018 OPP was designed to align the interests of senior management to relative and absolute performance of the Company over a three-year performance period from April 20, 2018 through April 19, 2021. Participants in the 2018 OPP will only earn the full awards if, over the three -year performance period, the Company achieves a thirty-six percent ( 36% ) absolute TSR and if the Company’s TSR is in the 75th percentile of performance as compared to the office REITs in the NAREIT index.  LTIP Units will remain subject to forfeiture depending on the extent that the 2016 LTIP Awards, 2017 LTIP Awards and 2018 LTIP Awards vest. The number of LTIP Units to be issued initially to recipients of the 2016 PBV LTIP Awards, 2017 PBV LTIP Awards and 2018 PBV LTIP Awards is the maximum number of LTIP Units that may be earned under the awards. The number of LTIP Units that actually vest for each award recipient will be determined at the end of the performance measurement period. TSR for the Company and for the Index over the three-year measurement period and other circumstances will determine how many LTIP Units vest for each recipient; if they are fewer than the number issued initially, the balance will be forfeited as of the performance measurement date.  Prior to vesting, recipients of LTIP Units will be entitled to receive per unit distributions equal to one-tenth ( 10 percent) of the regular quarterly distributions payable on a common unit of limited partnership interest in the Operating Partnership (a “common unit”), but will not be entitled to receive any special distributions. Distributions with respect to the other nine-tenths ( 90 percent) of regular quarterly distributions payable on a common unit will accrue but shall only become payable upon vesting of the LTIP Unit. After vesting of the 2016 TBV LTIP Units, 2017 TBV LTIP Units and 2018 LTIP TBV Units or the end of the measurement period for the 2016 PBV LTIP Units, 2017 PBV LTIP Units and 2018 LTIP PBV Units, the number of LTIP Units, both vested and unvested, will be entitled to receive distributions in an amount per unit equal to distributions, both regular and special, payable on a common unit.  As a result of certain executive management and other personnel changes during the year ended December 31, 2018 , the former employees forfeited and cancelled 189,273 2016 LTIP Awards, 105,443 2017 LTIP Awards and 38,015 2018 LTIP Awards, and the Company accelerated the vesting of 22,215 2016 LTIP Awards and 32,849 2017 LTIP Awards. As of December 31, 2018 , a total of 332,302 2016 PBV LTIP Units, 108,764 2016 TBV LTIP Units, 370,509 2017 PBV LTIP Units, 69,522 2017 TBV LTIP Units, 629,252 2018 PBV LTIP Units and 196,757 2018 TBV LTIP Units, net of LTIP Units forfeited and cancelled resulting from executive management and other personnel changes, were outstanding. The LTIP Units were valued in accordance with ASC 718 – Stock Compensation, at their fair value. The Company has reserved shares of common stock under the 2013 Plan for issuance upon vesting and conversion of the LTIP Units in accordance with their terms and conditions.  As of December 31, 2018 , the Company had $11.2 million of total unrecognized compensation cost related to unvested LTIP awards granted under the Company’s stock compensation plans. That cost is expected to be recognized over a weighted average period of 2.4 years.  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 year s ended December 31, 2018 , 2017 and 2016 , 26,620 , 19,728 and 14,274 deferred stock units were earned, respectively. As of December 31, 2018 and 2017 , there were 236,383 and 210,738 deferred stock units outstanding, respectively.  EARNINGS PER SHARE/UNIT Basic EPS or EPU excludes dilution and is computed by dividing net income available to common shareholders or unitholders by the weighted average number of shares or units outstanding for the period. Diluted EPS or EPU 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 years ended December 31, 2018 , 2017 and 2016 in accordance with ASC 260, Earnings Per Share (dollars in thousands, except per share amounts) :  Mack-Cali Realty Corporation:    Year Ended December 31,  Computation of Basic EPS 2018 2017 2016  Net income $ 106,401 $ 33,718 $ 130,294  Add: Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Add (deduct): Noncontrolling interest in Operating Partnership (9,527) (2,711) (13,721)  Deduct: Redeemable noncontrolling interest (13,979) (8,840) -  Deduct: Redemption value adjustment of redeemable noncontrolling  interests attributable to common shareholders (11,425) (17,951) -  Net income available to common shareholders for basic earnings per share $ 72,686 $ 5,234 $ 117,224   Weighted average common shares 90,388 90,005 89,746   Basic EPS :  Net income available to common shareholders $ 0.80 $ 0.06 $ 1.31         Year Ended December 31,  Computation of Diluted EPS 2018 2017 2016  Net income available to common shareholders for basic earnings per share $ 72,686 $ 5,234 $ 117,224  Add (deduct): Noncontrolling interest in Operating Partnership 9,527 2,711 13,721  Deduct: Redemption value adjustment of redeemable noncontrolling  interests attributable to the Operating Partnership unitholders (1,296) (2,074) -  Net income available for diluted earnings per share $ 80,917 $ 5,871 $ 130,945   Weighted average common shares 100,724 100,703 100,498   Diluted EPS :  Net income available to common shareholders $ 0.80 $ 0.06 $ 1.30   The following schedule reconciles the weighted average shares used in the basic EPS calculation to the shares used in the diluted EPS calculation (in thousands):   Year Ended December 31,  2018 2017 2016  Basic EPS shares 90,388 90,005 89,746  Add: Operating Partnership – common and vested LTIP units 10,246 10,405 10,499  Restricted Stock Awards - 40 43  Stock Options 90 253 210  Diluted EPS Shares 100,724 100,703 100,498  Contingently issuable shares under the PSU Awards were excluded from the denominator in 2017 and 2016 because the criteria had not been met for the periods. Contingently issuable shares under Restricted Stock Awards were excluded from the denominator in 2018 as such securities were anti-dilutive during the period. Also not included in the computations of diluted EPS were the unvested LTIP Units as such securities were anti-dilutive during all periods presented. Unvested restricted stock outstanding as of December 31, 2018 , 2017 and 2016 were 67,289 , 95,801 and 120,245 shares, respectively.  Dividends declared per common share for the years ended December 31, 2018 , 2017 and 2016 was $0.80 , $0.75 and $0.60 per share, respectively.  Mack-Cali Realty, L.P.:     Year Ended December 31,  Computation of Basic EPU 2018 2017 2016  Net income $ 106,401 $ 33,718 $ 130,294  Add: Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Deduct: Redeemable noncontrolling interest (13,979) (8,840) -  Deduct: Redemption value adjustment of redeemable noncontrolling interests (12,721) (20,025) -  Net income available to common unitholders for basic earnings per unit $ 80,917 $ 5,871 $ 130,945   Weighted average common units 100,634 100,410 100,245   Basic EPU :  Net income available to common unitholders for basic earnings per unit $ 0.80 $ 0.06 $ 1.31    Year Ended December 31,  Computation of Diluted EPU 2018 2017 2016  Net income available to common unitholders for diluted earnings per unit $ 80,917 $ 5,871 $ 130,945   Weighted average common unit 100,724 100,703 100,498   Diluted EPU :  Net income available to common unitholders $ 0.80 $ 0.06 $ 1.30  The following schedule reconciles the weighted average units used in the basic EPU calculation to the units used in the diluted EPU calculation (in thousands) :    Year Ended December 31,  2018 2017 2016  Basic EPU units 100,634 100,410 100,245  Add: Restricted Stock Awards - 40 43  Stock Options 90 253 210  Diluted EPU Units 100,724 100,703 100,498  Contingently issuable shares under the PSU Awards were excluded from the denominator in 2017 and 2016 because the criteria had not been met for the periods. Contingently issuable shares under Restricted Stock Awards were excluded from the denominator in 2018 as such securities were anti-dilutive during the period. Also not included in the computations of diluted EPU were the unvested LTIP Units as such securities were anti-dilutive during all periods presented. Unvested restricted stock outstanding as of December 31, 2018 , 2017 and 2016 were 67,289 , 95,801 and 120,245 shares, respectively.  Distributions declared per common unit for the years ended December 31, 2018 , 2017 and 2016 was $ 0.80 , $0.75 and $0.60 per unit, respectively.

Noncontrolling Interests In Sub

Noncontrolling Interests In Subsidiaries	12 Months Ended
	Dec. 31, 2018
Noncontrolling Interest [Line Items]
Noncontrolling Interests In Subsidiaries	16. NONCONTROLLING INTERESTS IN SUBSIDIARIES  Noncontrolling interests in subsidiaries in the accompanying consolidated financial statements relate to (i) common units and LTIP units in the Operating Partnership, held by parties other than the General Partner (“Limited Partners”), and (ii) interests in consolidated joint ventures for the portion of such ventures not owned by the Company.  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 value 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 year ended December 31, 2018 , the Company has decreased noncontrolling interests in the Operating Partnership and increased additional paid-in capital in Mack-Cali Realty Corporation stockholders’ equity by approximately $2.2 million as of December 31, 2018 .  NONCONTROLLING INTEREST IN OPERATING PARTNERSHIP (applicable only to General Partner)  Common Units Certain individuals and entities own common units in the Operating Partnership. A common unit and a share of Common Stock of the General Partner 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 General Partner’s Common Stock, or cash equal to the fair market value of a share of the General Partner’s Common Stock at the time of redemption, for each common unit. The General Partner, 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 General Partner 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 General Partner 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.  LTIP Units On March 8, 2016, the Company granted 2016 LTIP Awards to senior management of the Company, including the General Partner’s executive officers. On April 4, 2017, the Company granted 2017 LTIP Awards to senior management of the Company, including the General Partner’s executive officers. On April 20, 2018, the Company granted 2018 LTIP Awards to senior management of the Company, including the General Partner’s executive officers. All of the 2016 LTIP Awards, 2017 LTIP Awards and 2018 LTIP Awards are in the form of units in the Operating Partnership. See Note 15: Mack-Cali Realty Corporation Stockholders’ Equity and Mack-Cali Realty, L.P.’s Partners’ Capital – Long-Term Incentive Plan Awards.  LTIP Units are designed to qualify as “profits interests” in the Operating Partnership for federal income tax purposes. As a general matter, the profits interests characteristics of the LTIP Units mean that initially they will not be economically equivalent in value to a common unit. If and when events specified by applicable tax regulations occur, LTIP Units can over time increase in value up to the point where they are equivalent to common units on a one-for-one basis. After LTIP Units are fully vested, and to the extent the special tax rules applicable to profits interests have allowed them to become equivalent in value to common units, LTIP Units may be converted on a one-for-one basis into common units. Common units in turn have a one-for-one relationship in value with shares of the General Partner’s common stock, and are redeemable on a one-for-one basis for cash or, at the election of the Company, shares of the General Partner’s common stock.  Unit Transactions The following table sets forth the changes in noncontrolling interests in subsidiaries which relate to the common units and LTIP units in the Operating Partnership for the year s ended December 31, 2018 , 2017 and 2016 :     Common LTIP  Units Units  Balance at January 1, 2016 10,516,844 -  Redemption of common units for shares of common stock (28,739) -  Issuance of units - 657,373  Balance at December 31, 2016 10,488,105 657,373  Redemption of common units for shares of common stock (148,662) -  Issuance of units 99,412 578,323  Cancellation of units - (4,819)  Balance at December 31, 2017 10,438,855 1,230,877  Redemption of common units for shares of common stock (264,570) -  Issuance of units - 864,024  Cancellation of units - (332,731)   Balance at December 31, 2018 10,174,285 1,762,170  Noncontrolling Interest Ownership in Operating Partnership As of December 31, 2018 and 2017 , the noncontrolling interest common unitholders owned 10.2 percent and 10.4 percent of the Operating Partnership, respectively.  NONCONTROLLING INTEREST IN CONSOLIDATED JOINT VENTURES (applicable to General Partner and Operating Partnership)  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 ( two 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 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.
Mack-Cali Realty LP [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interests In Subsidiaries	16. NONCONTROLLING INTERESTS IN SUBSIDIARIES  Noncontrolling interests in subsidiaries in the accompanying consolidated financial statements relate to (i) common units and LTIP units in the Operating Partnership, held by parties other than the General Partner (“Limited Partners”), and (ii) interests in consolidated joint ventures for the portion of such ventures not owned by the Company.  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 value 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 year ended December 31, 2018 , the Company has decreased noncontrolling interests in the Operating Partnership and increased additional paid-in capital in Mack-Cali Realty Corporation stockholders’ equity by approximately $2.2 million as of December 31, 2018 .  NONCONTROLLING INTEREST IN OPERATING PARTNERSHIP (applicable only to General Partner)  Common Units Certain individuals and entities own common units in the Operating Partnership. A common unit and a share of Common Stock of the General Partner 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 General Partner’s Common Stock, or cash equal to the fair market value of a share of the General Partner’s Common Stock at the time of redemption, for each common unit. The General Partner, 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 General Partner 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 General Partner 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.  LTIP Units On March 8, 2016, the Company granted 2016 LTIP Awards to senior management of the Company, including the General Partner’s executive officers. On April 4, 2017, the Company granted 2017 LTIP Awards to senior management of the Company, including the General Partner’s executive officers. On April 20, 2018, the Company granted 2018 LTIP Awards to senior management of the Company, including the General Partner’s executive officers. All of the 2016 LTIP Awards, 2017 LTIP Awards and 2018 LTIP Awards are in the form of units in the Operating Partnership. See Note 15: Mack-Cali Realty Corporation Stockholders’ Equity and Mack-Cali Realty, L.P.’s Partners’ Capital – Long-Term Incentive Plan Awards.  LTIP Units are designed to qualify as “profits interests” in the Operating Partnership for federal income tax purposes. As a general matter, the profits interests characteristics of the LTIP Units mean that initially they will not be economically equivalent in value to a common unit. If and when events specified by applicable tax regulations occur, LTIP Units can over time increase in value up to the point where they are equivalent to common units on a one-for-one basis. After LTIP Units are fully vested, and to the extent the special tax rules applicable to profits interests have allowed them to become equivalent in value to common units, LTIP Units may be converted on a one-for-one basis into common units. Common units in turn have a one-for-one relationship in value with shares of the General Partner’s common stock, and are redeemable on a one-for-one basis for cash or, at the election of the Company, shares of the General Partner’s common stock.  Unit Transactions The following table sets forth the changes in noncontrolling interests in subsidiaries which relate to the common units and LTIP units in the Operating Partnership for the year s ended December 31, 2018 , 2017 and 2016 :     Common LTIP  Units Units  Balance at January 1, 2016 10,516,844 -  Redemption of common units for shares of common stock (28,739) -  Issuance of units - 657,373  Balance at December 31, 2016 10,488,105 657,373  Redemption of common units for shares of common stock (148,662) -  Issuance of units 99,412 578,323  Cancellation of units - (4,819)  Balance at December 31, 2017 10,438,855 1,230,877  Redemption of common units for shares of common stock (264,570) -  Issuance of units - 864,024  Cancellation of units - (332,731)   Balance at December 31, 2018 10,174,285 1,762,170  Noncontrolling Interest Ownership in Operating Partnership As of December 31, 2018 and 2017 , the noncontrolling interest common unitholders owned 10.2 percent and 10.4 percent of the Operating Partnership, respectively.  NONCONTROLLING INTEREST IN CONSOLIDATED JOINT VENTURES (applicable to General Partner and Operating Partnership)  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 ( two 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 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	12 Months Ended
	Dec. 31, 2018
Segment Reporting Information [Line Items]
Segment Reporting	17. SEGMENT REPORTING  The Company operates in two business segments: (i) commercial and other real estate and (ii) multi-family real estate and 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 had no revenues from foreign countries recorded for the year s ended December 31, 2018 , 2017 and 2016 . The Company had no long lived assets in foreign locations as of December 31, 2018 and 2017 . 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 and operations in each of its real estate segments (commercial and other real estate, and multi-family real estate and services).  Selected results of operations for the years ended December 31, 2018 , 2017 and 2016 , and selected asset information as of December 31, 2018 and 2017 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) :    Commercial Multi-family Corporate Total  & Other Real Estate Real Estate & Services (d) & Other (e) Company  Total revenues:  2018 $ 416,369 $ 113,805 $ 432 $ 530,606  2017 522,223 90,654 3,323 616,200  2016 541,271 69,873 2,254 613,398   Total operating and  interest expenses (a):  2018 $ 183,439 $ 70,280 $ 104,788 $ 358,507  2017 238,055 63,589 94,662 396,306  2016 263,663 60,646 91,042 415,351   Equity in earnings (loss) of  unconsolidated joint ventures:  2018 $ 2,319 $ (2,446) $ - $ (127)  2017 1,644 (7,725) - (6,081)  2016 23,796 (5,008) - 18,788  -  Net operating income (loss) (b):  2018 $ 235,249 $ 41,079 $ (104,356) $ 171,972  2017 285,812 19,340 (91,339) 213,813  2016 301,404 4,219 (88,788) 216,835   Total assets:  2018 $ 2,687,178 $ 2,260,497 $ 112,969 $ 5,060,644  2017 2,915,646 1,937,708 104,531 4,957,885   Total long-lived assets (c):  2018 $ 2,413,696 $ 1,973,826 $ 33,157 $ 4,420,679  2017 2,613,815 1,645,410 31,901 4,291,126   Total investments in  unconsolidated joint ventures:  2018 $ 13,699 $ 218,771 $ 280 $ 232,750  2017 15,143 237,321 162 252,626   (a) Total operating and interest expenses represent the sum of: real estate taxes; utilities; operating services; real estate services expenses; general and administrative, acquisition-related costs 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 and classified 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) Segment assets and operations were owned through a consolidated variable interest entity commencing in February 2018 . (e) Corporate & Other represents all corporate-level items (including interest and other investment income, interest expense, non-property general and administrative expense) as well as intercompany eliminations necessary to reconcile to consolidated Company totals. Mack-Cali Realty Corporation The following schedule reconciles net operating income to net income available to common shareholders (dollars in thousands) :      Year Ended December 31,  2018 2017 2016  Net operating income $ 171,972 $ 213,813 $ 216,835  Add (deduct):  Depreciation and amortization (174,847) (205,169) (186,684)  Land Impairments (24,566) - -  Gain on change of control of interests 14,217 - 15,347  Realized gains (losses) and unrealized losses on disposition of  rental property, net 99,436 2,364 109,666  Gain on disposition of developable land 30,939 - -  Gain on sale of investment in unconsolidated joint venture - 23,131 5,670  Loss from extinguishment of debt, net (10,750) (421) (30,540)  Net income 106,401 33,718 130,294  Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Noncontrolling interest in Operating Partnership (9,527) (2,711) (13,721)  Redeemable noncontrolling interest (13,979) (8,840) -  Net income available to common shareholders $ 84,111 $ 23,185 $ 117,224 Mack-Cali Realty, L.P. The following schedule reconciles net operating income to net income available to common unitholders (dollars in thousands) :     Year Ended December 31,  2018 2017 2016  Net operating income $ 171,972 $ 213,813 $ 216,835  Add (deduct):  Depreciation and amortization (174,847) (205,169) (186,684)  Land Impairments (24,566) - -  Gain on change of control of interests 14,217 - 15,347  Realized gains (losses) and unrealized losses on disposition of  rental property, net 99,436 2,364 109,666  Gain on disposition of developable land 30,939 - -  Gain on sale of investment in unconsolidated joint venture - 23,131 5,670  Loss from extinguishment of debt, net (10,750) (421) (30,540)  Net income 106,401 33,718 130,294  Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Redeemable noncontrolling interest (13,979) (8,840)  Net income available to common unitholders $ 93,638 $ 25,896 $ 130,945 
Mack-Cali Realty LP [Member]
Segment Reporting Information [Line Items]
Segment Reporting	17. SEGMENT REPORTING  The Company operates in two business segments: (i) commercial and other real estate and (ii) multi-family real estate and 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 had no revenues from foreign countries recorded for the year s ended December 31, 2018 , 2017 and 2016 . The Company had no long lived assets in foreign locations as of December 31, 2018 and 2017 . 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 and operations in each of its real estate segments (commercial and other real estate, and multi-family real estate and services).  Selected results of operations for the years ended December 31, 2018 , 2017 and 2016 , and selected asset information as of December 31, 2018 and 2017 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) :    Commercial Multi-family Corporate Total  & Other Real Estate Real Estate & Services (d) & Other (e) Company  Total revenues:  2018 $ 416,369 $ 113,805 $ 432 $ 530,606  2017 522,223 90,654 3,323 616,200  2016 541,271 69,873 2,254 613,398   Total operating and  interest expenses (a):  2018 $ 183,439 $ 70,280 $ 104,788 $ 358,507  2017 238,055 63,589 94,662 396,306  2016 263,663 60,646 91,042 415,351   Equity in earnings (loss) of  unconsolidated joint ventures:  2018 $ 2,319 $ (2,446) $ - $ (127)  2017 1,644 (7,725) - (6,081)  2016 23,796 (5,008) - 18,788  -  Net operating income (loss) (b):  2018 $ 235,249 $ 41,079 $ (104,356) $ 171,972  2017 285,812 19,340 (91,339) 213,813  2016 301,404 4,219 (88,788) 216,835   Total assets:  2018 $ 2,687,178 $ 2,260,497 $ 112,969 $ 5,060,644  2017 2,915,646 1,937,708 104,531 4,957,885   Total long-lived assets (c):  2018 $ 2,413,696 $ 1,973,826 $ 33,157 $ 4,420,679  2017 2,613,815 1,645,410 31,901 4,291,126   Total investments in  unconsolidated joint ventures:  2018 $ 13,699 $ 218,771 $ 280 $ 232,750  2017 15,143 237,321 162 252,626   (a) Total operating and interest expenses represent the sum of: real estate taxes; utilities; operating services; real estate services expenses; general and administrative, acquisition-related costs 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 and classified 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) Segment assets and operations were owned through a consolidated variable interest entity commencing in February 2018 . (e) Corporate & Other represents all corporate-level items (including interest and other investment income, interest expense, non-property general and administrative expense) as well as intercompany eliminations necessary to reconcile to consolidated Company totals. Mack-Cali Realty Corporation The following schedule reconciles net operating income to net income available to common shareholders (dollars in thousands) :      Year Ended December 31,  2018 2017 2016  Net operating income $ 171,972 $ 213,813 $ 216,835  Add (deduct):  Depreciation and amortization (174,847) (205,169) (186,684)  Land Impairments (24,566) - -  Gain on change of control of interests 14,217 - 15,347  Realized gains (losses) and unrealized losses on disposition of  rental property, net 99,436 2,364 109,666  Gain on disposition of developable land 30,939 - -  Gain on sale of investment in unconsolidated joint venture - 23,131 5,670  Loss from extinguishment of debt, net (10,750) (421) (30,540)  Net income 106,401 33,718 130,294  Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Noncontrolling interest in Operating Partnership (9,527) (2,711) (13,721)  Redeemable noncontrolling interest (13,979) (8,840) -  Net income available to common shareholders $ 84,111 $ 23,185 $ 117,224 Mack-Cali Realty, L.P. The following schedule reconciles net operating income to net income available to common unitholders (dollars in thousands) :     Year Ended December 31,  2018 2017 2016  Net operating income $ 171,972 $ 213,813 $ 216,835  Add (deduct):  Depreciation and amortization (174,847) (205,169) (186,684)  Land Impairments (24,566) - -  Gain on change of control of interests 14,217 - 15,347  Realized gains (losses) and unrealized losses on disposition of  rental property, net 99,436 2,364 109,666  Gain on disposition of developable land 30,939 - -  Gain on sale of investment in unconsolidated joint venture - 23,131 5,670  Loss from extinguishment of debt, net (10,750) (421) (30,540)  Net income 106,401 33,718 130,294  Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Redeemable noncontrolling interest (13,979) (8,840)  Net income available to common unitholders $ 93,638 $ 25,896 $ 130,945 

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions	18. RELATED PARTY TRANSACTIONS  William L. Mack, Chairman of the Board of Directors of the General Partner, David S. Mack, a director of the General Partner, and Earle I. Mack, a former director of the General Partner, are the executive officers, directors and stockholders of a corporation that leases approximately 7,034 square feet at one of the Company’s office properties (the Company disposed of this property in January 2019), which is scheduled to expire in September 2019 . The Company has recognized $193,000 , $187,000 and $193,000 in revenue under this lease for the years ended December 31, 2018 , 2017 and 2016 , respectively, and had no accounts receivable from the corporation as of December 31, 2018 and 2017 .  The adult children of Marshall Tycher, Chairman of RRT, own minority equity interests in a vendor to the Company. Additionally, Mr. Tycher’s son-in-law is an employee of the vendor. The Company recognized $148,000 in expense for this vendor during the year ended December 31, 2018 and had no accounts payable to this vendor as of December 31, 2018.  Certain executive officers of RRT and/or their family members (“RG”) directly or indirectly hold small noncontrolling interests in a certain consolidated joint venture. Additionally, the Company earned $1,114,000 , $1,873,000 , and $2,464,000 from entities in which RG has ownership interests for the years ended December 31, 2018 , 2017 and 2016 , respectively.
Mack-Cali Realty LP [Member]
Related Party Transactions	18. RELATED PARTY TRANSACTIONS  William L. Mack, Chairman of the Board of Directors of the General Partner, David S. Mack, a director of the General Partner, and Earle I. Mack, a former director of the General Partner, are the executive officers, directors and stockholders of a corporation that leases approximately 7,034 square feet at one of the Company’s office properties (the Company disposed of this property in January 2019), which is scheduled to expire in September 2019 . The Company has recognized $193,000 , $187,000 and $193,000 in revenue under this lease for the years ended December 31, 2018 , 2017 and 2016 , respectively, and had no accounts receivable from the corporation as of December 31, 2018 and 2017 .  The adult children of Marshall Tycher, Chairman of RRT, own minority equity interests in a vendor to the Company. Additionally, Mr. Tycher’s son-in-law is an employee of the vendor. The Company recognized $148,000 in expense for this vendor during the year ended December 31, 2018 and had no accounts payable to this vendor as of December 31, 2018.  Certain executive officers of RRT and/or their family members (“RG”) directly or indirectly hold small noncontrolling interests in a certain consolidated joint venture. Additionally, the Company earned $1,114,000 , $1,873,000 , and $2,464,000 from entities in which RG has ownership interests for the years ended December 31, 2018 , 2017 and 2016 , respectively.

Condensed Quarterly Financial I

Condensed Quarterly Financial Information	12 Months Ended
	Dec. 31, 2018
Condensed Quarterly Financial Information	19. CONDENSED QUARTERLY FINANCIAL INFORMATION (unaudited)  Mack-Cali Realty Corporation The following summarizes the condensed quarterly financial information for the Company (dollars in thousands) :      Quarter Ended 2018 December 31 September 30 June 30 March 31  Total revenues $ 132,936 $ 132,114 $ 126,589 $ 138,967  Net income $ 52,523 $ 1,689 $ 1,501 $ 50,688  Net income (loss) available to common shareholders $ 43,804 $ (1,478) $ (1,251) $ 43,036  `  Basic earnings per common share:  Net income (loss) available to common shareholders $ 0.45 $ (0.05) $ (0.05) $ 0.45   Diluted earnings per common share:  Net income (loss) available to common shareholders $ 0.45 $ (0.05) $ (0.05) $ 0.45       Quarter Ended 2017 December 31 September 30 June 30 March 31  Total revenues $ 143,529 $ 160,018 $ 162,766 $ 149,887  Net income (loss) $ 5,411 $ 44,703 $ (39,125) $ 22,729  Net income (loss) available to common shareholders $ 2,582 $ 38,054 $ (37,330) $ 19,879   Basic earnings per common share:  Net income (loss) available to common shareholders $ (0.01) $ 0.39 $ (0.44) $ 0.11   Diluted earnings per common share:  Net income (loss) available to common shareholders $ (0.01) $ 0.39 $ (0.44) $ 0.11 Mack-Cali Realty, L.P. The following summarizes the condensed quarterly financial information for the Company (dollars in thousands) :     Quarter Ended 2018 December 31 September 30 June 30 March 31  Total revenues $ 132,936 $ 132,114 $ 126,589 $ 138,967  Net income $ 52,523 $ 1,689 $ 1,501 $ 50,688  Net income (loss) available to common unitholders $ 48,757 $ (1,645) $ (1,393) $ 47,919   Basic earnings per common unit:  Net income (loss) available to common unitholders $ 0.45 $ (0.05) $ (0.05) $ 0.45   Diluted earnings per common units:  Net income (loss) available to common unitholders $ 0.45 $ (0.05) $ (0.05) $ 0.45      Quarter Ended 2017 December 31 September 30 June 30 March 31  Total revenues $ 143,529 $ 160,018 $ 162,766 $ 149,887  Net income (loss) $ 5,411 $ 44,703 $ (39,125) $ 22,729  Net income (loss) available to common unitholders $ 2,881 $ 42,467 $ (41,626) $ 22,174   Basic earnings per common unit:  Net income (loss) available to common unitholders $ (0.01) $ 0.39 $ (0.44) $ 0.11   Diluted earnings per common unit:  Net income (loss) available to common unitholders $ (0.01) $ 0.39 $ (0.44) $ 0.11 
Mack-Cali Realty LP [Member]
Condensed Quarterly Financial Information	19. CONDENSED QUARTERLY FINANCIAL INFORMATION (unaudited)  Mack-Cali Realty Corporation The following summarizes the condensed quarterly financial information for the Company (dollars in thousands) :      Quarter Ended 2018 December 31 September 30 June 30 March 31  Total revenues $ 132,936 $ 132,114 $ 126,589 $ 138,967  Net income $ 52,523 $ 1,689 $ 1,501 $ 50,688  Net income (loss) available to common shareholders $ 43,804 $ (1,478) $ (1,251) $ 43,036  `  Basic earnings per common share:  Net income (loss) available to common shareholders $ 0.45 $ (0.05) $ (0.05) $ 0.45   Diluted earnings per common share:  Net income (loss) available to common shareholders $ 0.45 $ (0.05) $ (0.05) $ 0.45       Quarter Ended 2017 December 31 September 30 June 30 March 31  Total revenues $ 143,529 $ 160,018 $ 162,766 $ 149,887  Net income (loss) $ 5,411 $ 44,703 $ (39,125) $ 22,729  Net income (loss) available to common shareholders $ 2,582 $ 38,054 $ (37,330) $ 19,879   Basic earnings per common share:  Net income (loss) available to common shareholders $ (0.01) $ 0.39 $ (0.44) $ 0.11   Diluted earnings per common share:  Net income (loss) available to common shareholders $ (0.01) $ 0.39 $ (0.44) $ 0.11 Mack-Cali Realty, L.P. The following summarizes the condensed quarterly financial information for the Company (dollars in thousands) :     Quarter Ended 2018 December 31 September 30 June 30 March 31  Total revenues $ 132,936 $ 132,114 $ 126,589 $ 138,967  Net income $ 52,523 $ 1,689 $ 1,501 $ 50,688  Net income (loss) available to common unitholders $ 48,757 $ (1,645) $ (1,393) $ 47,919   Basic earnings per common unit:  Net income (loss) available to common unitholders $ 0.45 $ (0.05) $ (0.05) $ 0.45   Diluted earnings per common units:  Net income (loss) available to common unitholders $ 0.45 $ (0.05) $ (0.05) $ 0.45      Quarter Ended 2017 December 31 September 30 June 30 March 31  Total revenues $ 143,529 $ 160,018 $ 162,766 $ 149,887  Net income (loss) $ 5,411 $ 44,703 $ (39,125) $ 22,729  Net income (loss) available to common unitholders $ 2,881 $ 42,467 $ (41,626) $ 22,174   Basic earnings per common unit:  Net income (loss) available to common unitholders $ (0.01) $ 0.39 $ (0.44) $ 0.11   Diluted earnings per common unit:  Net income (loss) available to common unitholders $ (0.01) $ 0.39 $ (0.44) $ 0.11 

Real Estate Investments And Acc

Real Estate Investments And Accumulated Depreciation	12 Months Ended
	Dec. 31, 2018
Real Estate Investments And Accumulated Depreciation	    MACK-CALI REALTY CORPORATION, MACK-CALI REALTY, L.P. AND SUBSIDIARIES  REAL ESTATE INVESTMENTS AND ACCUMULATED DEPRECIATION  December 31, 2018  (dollars in thousands)  SCHEDULE III  Gross Amount at Which  Costs Carried at Close of  Initial Costs Capitalized Period (a)  Property Year Related Building and Subsequent to Building and Accumulated  Property Location Type Built Acquired Encumbrances Land Improvements Acquisition(e) Land Improvements Total (d) Depreciation (b)   NEW JERSEY  Bergen County  Fort Lee  One Bridge Plaza Office 1981 1996 - 2,439 24,462 7,436 2,439 31,898 34,337 17,658   Essex County  Millburn  150 J.F. Kennedy Parkway Office 1980 1997 - 12,606 50,425 17,073 12,606 67,498 80,104 33,259  Roseland  51 J.F. Kennedy Parkway Office 1988 2017 69,459 5,873 100,359 575 5,873 100,934 106,807 6,806  101 J.F. Kennedy Parkway Office 1981 2017 29,197 4,380 59,730 1,151 4,380 60,881 65,261 4,063  103 J.F. Kennedy Parkway Office 1981 2017 24,875 3,158 50,813 469 3,158 51,282 54,440 3,434   Hudson County  Hoboken  111 River Street Office 2002 2016 - 204 198,609 14,932 - 213,745 213,745 14,364  Jersey City  Harborside Plaza 1 Office 1983 1996 - 3,923 51,013 26,426 3,923 77,439 81,362 41,749  Harborside Plaza 2 Office 1990 1996 - 17,655 101,546 53,393 8,364 164,230 172,594 69,838  Harborside Plaza 3 Office 1990 1996 - 17,655 101,878 53,060 8,363 164,230 172,593 69,838  Harborside Plaza 4A Office 2000 2000 - 1,244 56,144 8,688 1,244 64,832 66,076 31,301  Harborside Plaza 5 Office 2002 2002 - 6,218 170,682 60,698 5,705 231,893 237,598 101,850  101 Hudson Street Office 1992 2005 248,460 45,530 271,376 33,508 45,530 304,884 350,414 103,639  Rosegarden Monaco Multi-Family 2011 2017 168,370 58,761 240,871 434 58,761 241,305 300,066 10,720  Marbella I Multi-Family 2003 2018 130,040 48,820 160,740 1,306 48,820 162,046 210,866 1,711  Weehawken  100 Avenue at Port Imperial Other 2016 2016 - 350 - 4,205 471 4,084 4,555 310  500 Avenue at Port Imperial Other 2013 2013 36,568 13,099 56,669 (19,756) 13,099 36,913 50,012 4,925  Port Imperial South 11 Multi-Family 2018 2018 99,792 - - - 22,047 108,392 130,439 577   Mercer County  Princeton  100 Overlook Center Office 1988 1997 - 2,378 21,754 4,577 2,378 26,331 28,709 13,218  5 Vaughn Drive Office 1987 1995 - 657 9,800 1,564 657 11,364 12,021 6,529   Middlesex County  Edison  333 Thornall Street Office 1984 2015 - 5,542 40,762 3,686 5,542 44,448 49,990 4,933  343 Thornall Street Office 1991 2006 - 6,027 39,101 15,160 6,027 54,261 60,288 16,308  Iselin  101 Wood Avenue South Office 1990 2016 - 8,509 72,738 1,183 7,384 75,046 82,430 6,936  New Brunswick  Richmond Court Multi-Family 1997 2013 - 2,992 13,534 1,908 2,992 15,442 18,434 1,856  Riverwatch Commons Multi-Family 1995 2013 - 4,169 18,974 2,187 4,169 21,161 25,330 2,534  Plainsboro  500 College Road East (c) Office 1984 1998 614 20,626 5,776 614 26,402 27,016 14,225  Woodbridge  581 Main Street Office 1991 1997 - 3,237 12,949 35,315 8,115 43,386 51,501 16,482   Monmouth County  Holmdel  23 Main Street Office 1977 2005 - 4,336 19,544 6,377 4,336 25,921 30,257 8,116  Middletown  One River Center, Building 1 Office 1983 2004 - 3,070 17,414 16,094 2,451 34,127 36,578 8,385  One River Center, Building 2 Office 1983 2004 - 2,468 15,043 4,175 2,452 19,234 21,686 7,880  One River Center, Building 3 Office 1984 2004 - 4,051 24,790 5,688 4,627 29,902 34,529 11,525  Neptune  3600 Route 66 Office 1989 1995 - 1,098 18,146 11,461 1,098 29,607 30,705 15,555  Red Bank  100 Schultz Drive Office 1989 2017 - 1,953 6,790 1,126 1,953 7,916 9,869 905  200 Schultz Drive Office 1989 2017 - 2,184 8,259 1,165 2,184 9,424 11,608 1,003       MACK-CALI REALTY CORPORATION, MACK-CALI REALTY, L.P. AND SUBSIDIARIES  REAL ESTATE INVESTMENTS AND ACCUMULATED DEPRECIATION  December 31, 2018  (dollars in thousands)  SCHEDULE III  Gross Amount at Which  Costs Carried at Close of  Initial Costs Capitalized Period (a)  Property Year Related Building and Subsequent to Building and Accumulated  Property Location Type Built Acquired Encumbrances Land Improvements Acquisition(e) Land Improvements Total (d) Depreciation (b)   Morris County  Florham Park  325 Columbia Parkway Office 1987 1994 - 1,564 - 18,616 1,564 18,616 20,180 13,036  Madison  1 Giralda Farms Office 1982 2017 - 3,370 27,145 734 3,370 27,879 31,249 2,260  7 Giralda Farms Office 1997 2017 - 5,402 5,402 510 5,402 38,174 43,576 2,766  Morris Plains  Signature Place Multi-Family 41,703 930 - 56,373 930 56,373 57,303 922  Parsippany  4 Campus Drive Office 1983 2001 - 5,213 20,984 4,052 5,213 25,036 30,249 11,490  6 Campus Drive Office 1983 2001 - 4,411 17,796 3,945 4,411 21,741 26,152 9,665  7 Campus Drive Office 1982 1998 - 1,932 27,788 6,757 1,932 34,545 36,477 18,408  8 Campus Drive Office 1987 1998 - 1,865 35,456 12,475 1,865 47,931 49,796 22,089  9 Campus Drive Office 1983 2001 - 3,277 11,796 22,721 5,842 31,952 37,794 13,474  2 Dryden Way Office 1990 1998 - 778 420 110 778 530 1,308 320  4 Gatehall Drive Office 1988 2000 - 8,452 33,929 7,788 8,452 41,717 50,169 18,726  2 Hilton Court Office 1991 1998 - 1,971 32,007 4,474 1,971 36,481 38,452 19,992  1 Sylvan Way Office 1989 1998 - 1,689 24,699 4,984 1,021 30,351 31,372 14,094  3 Sylvan Way Office 1988 2015 - 5,590 4,710 9,840 5,590 14,550 20,140 845  5 Sylvan Way Office 1989 1998 - 1,160 25,214 7,056 1,161 32,269 33,430 14,774  7 Sylvan Way Office 1987 1998 - 2,084 26,083 14,823 2,084 40,906 42,990 15,697  5 Wood Hollow Road Office 1979 2004 - 5,302 26,488 21,087 5,302 47,575 52,877 21,689   NEW YORK  Westchester County  Eastchester  Quarry Place at Tuckahoe Multi-Family 2016 2016 40,433 5,585 3,400 48,718 5,585 52,118 57,703 2,573  Elmsford  11 Clearbrook Road Office/Flex 1974 1997 - 149 2,159 504 149 2,663 2,812 1,479  75 Clearbrook Road Office/Flex 1990 1997 - 2,314 4,716 57 2,314 4,773 7,087 2,621  100 Clearbrook Road Office 1975 1997 - 220 5,366 1,846 220 7,212 7,432 3,620  125 Clearbrook Road Office/Flex 2002 2002 - 1,055 3,676 (292) 1,055 3,384 4,439 1,685  150 Clearbrook Road Office/Flex 1975 1997 - 497 7,030 2,198 497 9,228 9,725 4,927  175 Clearbrook Road Office/Flex 1973 1997 - 655 7,473 973 655 8,446 9,101 4,731  200 Clearbrook Road Office/Flex 1974 1997 - 579 6,620 1,667 579 8,287 8,866 4,343  250 Clearbrook Road Office/Flex 1973 1997 - 867 8,647 2,387 867 11,034 11,901 5,813  50 Executive Boulevard Office/Flex 1969 1997 - 237 2,617 540 237 3,157 3,394 1,731  77 Executive Boulevard Office/Flex 1977 1997 - 34 1,104 179 34 1,283 1,317 740  85 Executive Boulevard Office/Flex 1968 1997 - 155 2,507 456 155 2,963 3,118 1,584  101 Executive Boulevard Office 1971 1997 - 267 5,838 (6,105) - - - -  300 Executive Boulevard Office/Flex 1970 1997 - 460 3,609 307 460 3,916 4,376 2,132  350 Executive Boulevard Office/Flex 1970 1997 - 100 1,793 175 100 1,968 2,068 1,146  399 Executive Boulevard Office/Flex 1962 1997 - 531 7,191 163 531 7,354 7,885 4,077  400 Executive Boulevard Office/Flex 1970 1997 - 2,202 1,846 1,140 2,202 2,986 5,188 1,807  500 Executive Boulevard Office/Flex 1970 1997 - 258 4,183 508 258 4,691 4,949 2,655  525 Executive Boulevard Office/Flex 1972 1997 - 345 5,499 837 345 6,336 6,681 3,661  1 Westchester Plaza Office/Flex 1967 1997 - 199 2,023 183 199 2,206 2,405 1,214  2 Westchester Plaza Office/Flex 1968 1997 - 234 2,726 914 234 3,640 3,874 1,971  3 Westchester Plaza Office/Flex 1969 1997 - 655 7,936 1,433 655 9,369 10,024 4,876  4 Westchester Plaza Office/Flex 1969 1997 - 320 3,729 1,531 320 5,260 5,580 2,512  5 Westchester Plaza Office/Flex 1969 1997 - 118 1,949 303 118 2,252 2,370 1,184  6 Westchester Plaza Office/Flex 1968 1997 - 164 1,998 202 164 2,200 2,364 1,197  7 Westchester Plaza Office/Flex 1972 1997 - 286 4,321 1,168 286 5,489 5,775 2,781  8 Westchester Plaza Office/Flex 1971 1997 - 447 5,262 2,127 447 7,389 7,836 4,025  Hawthorne  200 Saw Mill River Road Office/Flex 1965 1997 - 353 3,353 833 353 4,186 4,539 2,110  1 Skyline Drive Office 1980 1997 - 66 1,711 210 66 1,921 1,987 1,102  2 Skyline Drive Office 1987 1997 - 109 3,128 1,474 109 4,602 4,711 2,909  4 Skyline Drive Office/Flex 1987 1997 - 363 7,513 2,140 363 9,653 10,016 5,635  5 Skyline Drive Office/Flex 1980 2001 - 2,219 8,916 1,472 2,219 10,388 12,607 5,340  6 Skyline Drive Office/Flex 1980 2001 - 740 2,971 535 740 3,506 4,246 1,942  7 Skyline Drive Office 1987 1998 - 330 13,013 2,733 330 15,746 16,076 8,071  8 Skyline Drive Office/Flex 1985 1997 - 212 4,410 836 212 5,246 5,458 3,036  10 Skyline Drive Office/Flex 1985 1997 - 134 2,799 271 134 3,070 3,204 1,630  11 Skyline Drive (c) Office/Flex 1989 1997 - - 4,788 763 - 5,551 5,551 2,906  12 Skyline Drive (c) Office/Flex 1999 1999 - 1,562 3,254 218 1,320 3,714 5,034 1,911  15 Skyline Drive (c) Office/Flex 1989 1997 - - 7,449 1,858 - 9,307 9,307 4,537  17 Skyline Drive (c) Office 1989 1997 - - 7,269 1,248 - 8,517 8,517 4,547          MACK-CALI REALTY CORPORATION, MACK-CALI REALTY, L.P. AND SUBSIDIARIES  REAL ESTATE INVESTMENTS AND ACCUMULATED DEPRECIATION  December 31, 2018  (dollars in thousands)  SCHEDULE III  Gross Amount at Which  Costs Carried at Close of  Initial Costs Capitalized Period (a)  Property Year Related Building and Subsequent to Building and Accumulated  Property Location Type Built Acquired Encumbrances Land Improvements Acquisition(e) Land Improvements Total (d) Depreciation (b)   Tarrytown  230 White Plains Road Retail 1984 1997 - 124 1,845 288 124 2,133 2,257 1,108  Yonkers  100 Corporate Boulevard Office/Flex 1987 1997 - 602 9,910 1,175 602 11,085 11,687 6,143  200 Corporate Boulevard South Office/Flex 1990 1997 - 502 7,575 2,585 502 10,160 10,662 5,017  1 Executive Boulevard Office 1982 1997 - 1,104 11,904 3,688 1,105 15,591 16,696 8,210  2 Executive Boulevard Retail 1986 1997 - 89 2,439 107 89 2,546 2,635 1,397  3 Executive Boulevard Office 1987 1997 - 385 6,256 1,803 385 8,059 8,444 4,496  4 Executive Plaza Office/Flex 1986 1997 - 584 6,134 854 584 6,988 7,572 3,723  6 Executive Plaza Office/Flex 1987 1997 - 546 7,246 2,212 546 9,458 10,004 5,127  1 Odell Plaza Office/Flex 1980 1997 - 1,206 6,815 2,349 1,206 9,164 10,370 5,093  3 Odell Plaza Office 1984 2003 - 1,322 4,777 2,360 1,322 7,137 8,459 3,976  5 Odell Plaza Office/Flex 1983 1997 - 331 2,988 476 331 3,464 3,795 2,029  7 Odell Plaza Office/Flex 1984 1997 - 419 4,418 1,303 419 5,721 6,140 2,938   CONNECTICUT  Fairfield County  Stamford  419 West Avenue Office/Flex 1986 1997 - 4,538 9,246 482 4,538 9,728 14,266 5,316  500 West Avenue Office/Flex 1988 1997 - 415 1,679 646 415 2,325 2,740 1,221  550 West Avenue Office/Flex 1990 1997 - 1,975 3,856 133 1,975 3,989 5,964 2,172  600 West Avenue Office/Flex 1999 1999 - 2,305 2,863 1,184 2,305 4,047 6,352 1,739  650 West Avenue Office/Flex 1998 1998 - 1,328 - 3,247 1,328 3,247 4,575 1,805   MASSACHUSETTS  Middlesex County  Malden  The Chase at Overlook Ridge Multi-Family 2016 2016 134,839 11,072 87,793 74,692 21,827 151,730 173,557 9,969   Suffolk County  East Boston  Portside at Pier One Multi-Family 2016 2016 58,644 - 73,713 446 - 74,159 74,159 6,163  Portside 5/6 Multi-Family 2018 2018 96,369 - - - - 113,913 113,913 1,268  Revere  Alterra at Overlook Ridge IA Multi-Family 2004 2013 40,102 9,042 50,671 1,072 9,042 51,743 60,785 7,933  Alterra at Overlook Ridge II Multi-Family 2008 2013 59,371 12,055 71,409 409 12,056 71,817 83,873 10,980   Projects Under Development  and Developable Land 128,017 363,373 494,764 - 363,373 494,764 858,137 14,726   Furniture, Fixtures  and Equipment - - - 53,718 - 53,718 53,718 15,879   TOTALS 1,406,239 788,528 3,429,551 811,324 807,236 4,498,781 5,306,017 1,097,868    (a) The aggregate cost for federal income tax purposes at December 31, 2018 was approximately $5.1 billion. (b) Depreciation of buildings and improvements are calculated over lives ranging from the life of the lease to 40 years. (c) This property is located on land leased by the Company. (d) Properties identified as held for sale at December 31, 2018 are excluded. (e) These costs are net of impairments and valuation allowances recorded, if any.  MACK-CALI REALTY CORPORATION/MACK-CALI REALTY, L.P. AND SUBSIDIARIES NOTE TO SCHEDULE III    Changes in rental properties and accumulated depreciation for the periods ended December 31, 2018 , 2017 and 2016 are as follows: (dollars in thousands)     2018 2017 2016  Rental Properties  Balance at beginning of year $ 5,102,844 $ 4,804,867 $ 4,807,718  Additions 686,452 1,179,365 819,535  Rental property held for sale (184,233) (310,089) (79,200)  Properties sold (238,873) (538,424) (695,837)  Impairments - - -  Retirements/disposals (60,173) (32,875) (47,349)  Balance at end of year $ 5,306,017 $ 5,102,844 $ 4,804,867    Accumulated Depreciation  Balance at beginning of year $ 1,087,083 $ 1,332,073 $ 1,464,482  Depreciation expense 140,726 154,343 151,569  Rental property held for sale (30,404) (126,503) (31,792)  Properties sold (39,364) (217,625) (204,837)  Repurposed buildings - (22,330) -  Impairments - - -  Retirements/disposals (60,173) (32,875) (47,349)  Balance at end of year $ 1,097,868 $ 1,087,083 $ 1,332,073   Schadf      
Mack-Cali Realty LP [Member]
Real Estate Investments And Accumulated Depreciation	    MACK-CALI REALTY CORPORATION, MACK-CALI REALTY, L.P. AND SUBSIDIARIES  REAL ESTATE INVESTMENTS AND ACCUMULATED DEPRECIATION  December 31, 2018  (dollars in thousands)  SCHEDULE III  Gross Amount at Which  Costs Carried at Close of  Initial Costs Capitalized Period (a)  Property Year Related Building and Subsequent to Building and Accumulated  Property Location Type Built Acquired Encumbrances Land Improvements Acquisition(e) Land Improvements Total (d) Depreciation (b)   NEW JERSEY  Bergen County  Fort Lee  One Bridge Plaza Office 1981 1996 - 2,439 24,462 7,436 2,439 31,898 34,337 17,658   Essex County  Millburn  150 J.F. Kennedy Parkway Office 1980 1997 - 12,606 50,425 17,073 12,606 67,498 80,104 33,259  Roseland  51 J.F. Kennedy Parkway Office 1988 2017 69,459 5,873 100,359 575 5,873 100,934 106,807 6,806  101 J.F. Kennedy Parkway Office 1981 2017 29,197 4,380 59,730 1,151 4,380 60,881 65,261 4,063  103 J.F. Kennedy Parkway Office 1981 2017 24,875 3,158 50,813 469 3,158 51,282 54,440 3,434   Hudson County  Hoboken  111 River Street Office 2002 2016 - 204 198,609 14,932 - 213,745 213,745 14,364  Jersey City  Harborside Plaza 1 Office 1983 1996 - 3,923 51,013 26,426 3,923 77,439 81,362 41,749  Harborside Plaza 2 Office 1990 1996 - 17,655 101,546 53,393 8,364 164,230 172,594 69,838  Harborside Plaza 3 Office 1990 1996 - 17,655 101,878 53,060 8,363 164,230 172,593 69,838  Harborside Plaza 4A Office 2000 2000 - 1,244 56,144 8,688 1,244 64,832 66,076 31,301  Harborside Plaza 5 Office 2002 2002 - 6,218 170,682 60,698 5,705 231,893 237,598 101,850  101 Hudson Street Office 1992 2005 248,460 45,530 271,376 33,508 45,530 304,884 350,414 103,639  Rosegarden Monaco Multi-Family 2011 2017 168,370 58,761 240,871 434 58,761 241,305 300,066 10,720  Marbella I Multi-Family 2003 2018 130,040 48,820 160,740 1,306 48,820 162,046 210,866 1,711  Weehawken  100 Avenue at Port Imperial Other 2016 2016 - 350 - 4,205 471 4,084 4,555 310  500 Avenue at Port Imperial Other 2013 2013 36,568 13,099 56,669 (19,756) 13,099 36,913 50,012 4,925  Port Imperial South 11 Multi-Family 2018 2018 99,792 - - - 22,047 108,392 130,439 577   Mercer County  Princeton  100 Overlook Center Office 1988 1997 - 2,378 21,754 4,577 2,378 26,331 28,709 13,218  5 Vaughn Drive Office 1987 1995 - 657 9,800 1,564 657 11,364 12,021 6,529   Middlesex County  Edison  333 Thornall Street Office 1984 2015 - 5,542 40,762 3,686 5,542 44,448 49,990 4,933  343 Thornall Street Office 1991 2006 - 6,027 39,101 15,160 6,027 54,261 60,288 16,308  Iselin  101 Wood Avenue South Office 1990 2016 - 8,509 72,738 1,183 7,384 75,046 82,430 6,936  New Brunswick  Richmond Court Multi-Family 1997 2013 - 2,992 13,534 1,908 2,992 15,442 18,434 1,856  Riverwatch Commons Multi-Family 1995 2013 - 4,169 18,974 2,187 4,169 21,161 25,330 2,534  Plainsboro  500 College Road East (c) Office 1984 1998 614 20,626 5,776 614 26,402 27,016 14,225  Woodbridge  581 Main Street Office 1991 1997 - 3,237 12,949 35,315 8,115 43,386 51,501 16,482   Monmouth County  Holmdel  23 Main Street Office 1977 2005 - 4,336 19,544 6,377 4,336 25,921 30,257 8,116  Middletown  One River Center, Building 1 Office 1983 2004 - 3,070 17,414 16,094 2,451 34,127 36,578 8,385  One River Center, Building 2 Office 1983 2004 - 2,468 15,043 4,175 2,452 19,234 21,686 7,880  One River Center, Building 3 Office 1984 2004 - 4,051 24,790 5,688 4,627 29,902 34,529 11,525  Neptune  3600 Route 66 Office 1989 1995 - 1,098 18,146 11,461 1,098 29,607 30,705 15,555  Red Bank  100 Schultz Drive Office 1989 2017 - 1,953 6,790 1,126 1,953 7,916 9,869 905  200 Schultz Drive Office 1989 2017 - 2,184 8,259 1,165 2,184 9,424 11,608 1,003       MACK-CALI REALTY CORPORATION, MACK-CALI REALTY, L.P. AND SUBSIDIARIES  REAL ESTATE INVESTMENTS AND ACCUMULATED DEPRECIATION  December 31, 2018  (dollars in thousands)  SCHEDULE III  Gross Amount at Which  Costs Carried at Close of  Initial Costs Capitalized Period (a)  Property Year Related Building and Subsequent to Building and Accumulated  Property Location Type Built Acquired Encumbrances Land Improvements Acquisition(e) Land Improvements Total (d) Depreciation (b)   Morris County  Florham Park  325 Columbia Parkway Office 1987 1994 - 1,564 - 18,616 1,564 18,616 20,180 13,036  Madison  1 Giralda Farms Office 1982 2017 - 3,370 27,145 734 3,370 27,879 31,249 2,260  7 Giralda Farms Office 1997 2017 - 5,402 5,402 510 5,402 38,174 43,576 2,766  Morris Plains  Signature Place Multi-Family 41,703 930 - 56,373 930 56,373 57,303 922  Parsippany  4 Campus Drive Office 1983 2001 - 5,213 20,984 4,052 5,213 25,036 30,249 11,490  6 Campus Drive Office 1983 2001 - 4,411 17,796 3,945 4,411 21,741 26,152 9,665  7 Campus Drive Office 1982 1998 - 1,932 27,788 6,757 1,932 34,545 36,477 18,408  8 Campus Drive Office 1987 1998 - 1,865 35,456 12,475 1,865 47,931 49,796 22,089  9 Campus Drive Office 1983 2001 - 3,277 11,796 22,721 5,842 31,952 37,794 13,474  2 Dryden Way Office 1990 1998 - 778 420 110 778 530 1,308 320  4 Gatehall Drive Office 1988 2000 - 8,452 33,929 7,788 8,452 41,717 50,169 18,726  2 Hilton Court Office 1991 1998 - 1,971 32,007 4,474 1,971 36,481 38,452 19,992  1 Sylvan Way Office 1989 1998 - 1,689 24,699 4,984 1,021 30,351 31,372 14,094  3 Sylvan Way Office 1988 2015 - 5,590 4,710 9,840 5,590 14,550 20,140 845  5 Sylvan Way Office 1989 1998 - 1,160 25,214 7,056 1,161 32,269 33,430 14,774  7 Sylvan Way Office 1987 1998 - 2,084 26,083 14,823 2,084 40,906 42,990 15,697  5 Wood Hollow Road Office 1979 2004 - 5,302 26,488 21,087 5,302 47,575 52,877 21,689   NEW YORK  Westchester County  Eastchester  Quarry Place at Tuckahoe Multi-Family 2016 2016 40,433 5,585 3,400 48,718 5,585 52,118 57,703 2,573  Elmsford  11 Clearbrook Road Office/Flex 1974 1997 - 149 2,159 504 149 2,663 2,812 1,479  75 Clearbrook Road Office/Flex 1990 1997 - 2,314 4,716 57 2,314 4,773 7,087 2,621  100 Clearbrook Road Office 1975 1997 - 220 5,366 1,846 220 7,212 7,432 3,620  125 Clearbrook Road Office/Flex 2002 2002 - 1,055 3,676 (292) 1,055 3,384 4,439 1,685  150 Clearbrook Road Office/Flex 1975 1997 - 497 7,030 2,198 497 9,228 9,725 4,927  175 Clearbrook Road Office/Flex 1973 1997 - 655 7,473 973 655 8,446 9,101 4,731  200 Clearbrook Road Office/Flex 1974 1997 - 579 6,620 1,667 579 8,287 8,866 4,343  250 Clearbrook Road Office/Flex 1973 1997 - 867 8,647 2,387 867 11,034 11,901 5,813  50 Executive Boulevard Office/Flex 1969 1997 - 237 2,617 540 237 3,157 3,394 1,731  77 Executive Boulevard Office/Flex 1977 1997 - 34 1,104 179 34 1,283 1,317 740  85 Executive Boulevard Office/Flex 1968 1997 - 155 2,507 456 155 2,963 3,118 1,584  101 Executive Boulevard Office 1971 1997 - 267 5,838 (6,105) - - - -  300 Executive Boulevard Office/Flex 1970 1997 - 460 3,609 307 460 3,916 4,376 2,132  350 Executive Boulevard Office/Flex 1970 1997 - 100 1,793 175 100 1,968 2,068 1,146  399 Executive Boulevard Office/Flex 1962 1997 - 531 7,191 163 531 7,354 7,885 4,077  400 Executive Boulevard Office/Flex 1970 1997 - 2,202 1,846 1,140 2,202 2,986 5,188 1,807  500 Executive Boulevard Office/Flex 1970 1997 - 258 4,183 508 258 4,691 4,949 2,655  525 Executive Boulevard Office/Flex 1972 1997 - 345 5,499 837 345 6,336 6,681 3,661  1 Westchester Plaza Office/Flex 1967 1997 - 199 2,023 183 199 2,206 2,405 1,214  2 Westchester Plaza Office/Flex 1968 1997 - 234 2,726 914 234 3,640 3,874 1,971  3 Westchester Plaza Office/Flex 1969 1997 - 655 7,936 1,433 655 9,369 10,024 4,876  4 Westchester Plaza Office/Flex 1969 1997 - 320 3,729 1,531 320 5,260 5,580 2,512  5 Westchester Plaza Office/Flex 1969 1997 - 118 1,949 303 118 2,252 2,370 1,184  6 Westchester Plaza Office/Flex 1968 1997 - 164 1,998 202 164 2,200 2,364 1,197  7 Westchester Plaza Office/Flex 1972 1997 - 286 4,321 1,168 286 5,489 5,775 2,781  8 Westchester Plaza Office/Flex 1971 1997 - 447 5,262 2,127 447 7,389 7,836 4,025  Hawthorne  200 Saw Mill River Road Office/Flex 1965 1997 - 353 3,353 833 353 4,186 4,539 2,110  1 Skyline Drive Office 1980 1997 - 66 1,711 210 66 1,921 1,987 1,102  2 Skyline Drive Office 1987 1997 - 109 3,128 1,474 109 4,602 4,711 2,909  4 Skyline Drive Office/Flex 1987 1997 - 363 7,513 2,140 363 9,653 10,016 5,635  5 Skyline Drive Office/Flex 1980 2001 - 2,219 8,916 1,472 2,219 10,388 12,607 5,340  6 Skyline Drive Office/Flex 1980 2001 - 740 2,971 535 740 3,506 4,246 1,942  7 Skyline Drive Office 1987 1998 - 330 13,013 2,733 330 15,746 16,076 8,071  8 Skyline Drive Office/Flex 1985 1997 - 212 4,410 836 212 5,246 5,458 3,036  10 Skyline Drive Office/Flex 1985 1997 - 134 2,799 271 134 3,070 3,204 1,630  11 Skyline Drive (c) Office/Flex 1989 1997 - - 4,788 763 - 5,551 5,551 2,906  12 Skyline Drive (c) Office/Flex 1999 1999 - 1,562 3,254 218 1,320 3,714 5,034 1,911  15 Skyline Drive (c) Office/Flex 1989 1997 - - 7,449 1,858 - 9,307 9,307 4,537  17 Skyline Drive (c) Office 1989 1997 - - 7,269 1,248 - 8,517 8,517 4,547          MACK-CALI REALTY CORPORATION, MACK-CALI REALTY, L.P. AND SUBSIDIARIES  REAL ESTATE INVESTMENTS AND ACCUMULATED DEPRECIATION  December 31, 2018  (dollars in thousands)  SCHEDULE III  Gross Amount at Which  Costs Carried at Close of  Initial Costs Capitalized Period (a)  Property Year Related Building and Subsequent to Building and Accumulated  Property Location Type Built Acquired Encumbrances Land Improvements Acquisition(e) Land Improvements Total (d) Depreciation (b)   Tarrytown  230 White Plains Road Retail 1984 1997 - 124 1,845 288 124 2,133 2,257 1,108  Yonkers  100 Corporate Boulevard Office/Flex 1987 1997 - 602 9,910 1,175 602 11,085 11,687 6,143  200 Corporate Boulevard South Office/Flex 1990 1997 - 502 7,575 2,585 502 10,160 10,662 5,017  1 Executive Boulevard Office 1982 1997 - 1,104 11,904 3,688 1,105 15,591 16,696 8,210  2 Executive Boulevard Retail 1986 1997 - 89 2,439 107 89 2,546 2,635 1,397  3 Executive Boulevard Office 1987 1997 - 385 6,256 1,803 385 8,059 8,444 4,496  4 Executive Plaza Office/Flex 1986 1997 - 584 6,134 854 584 6,988 7,572 3,723  6 Executive Plaza Office/Flex 1987 1997 - 546 7,246 2,212 546 9,458 10,004 5,127  1 Odell Plaza Office/Flex 1980 1997 - 1,206 6,815 2,349 1,206 9,164 10,370 5,093  3 Odell Plaza Office 1984 2003 - 1,322 4,777 2,360 1,322 7,137 8,459 3,976  5 Odell Plaza Office/Flex 1983 1997 - 331 2,988 476 331 3,464 3,795 2,029  7 Odell Plaza Office/Flex 1984 1997 - 419 4,418 1,303 419 5,721 6,140 2,938   CONNECTICUT  Fairfield County  Stamford  419 West Avenue Office/Flex 1986 1997 - 4,538 9,246 482 4,538 9,728 14,266 5,316  500 West Avenue Office/Flex 1988 1997 - 415 1,679 646 415 2,325 2,740 1,221  550 West Avenue Office/Flex 1990 1997 - 1,975 3,856 133 1,975 3,989 5,964 2,172  600 West Avenue Office/Flex 1999 1999 - 2,305 2,863 1,184 2,305 4,047 6,352 1,739  650 West Avenue Office/Flex 1998 1998 - 1,328 - 3,247 1,328 3,247 4,575 1,805   MASSACHUSETTS  Middlesex County  Malden  The Chase at Overlook Ridge Multi-Family 2016 2016 134,839 11,072 87,793 74,692 21,827 151,730 173,557 9,969   Suffolk County  East Boston  Portside at Pier One Multi-Family 2016 2016 58,644 - 73,713 446 - 74,159 74,159 6,163  Portside 5/6 Multi-Family 2018 2018 96,369 - - - - 113,913 113,913 1,268  Revere  Alterra at Overlook Ridge IA Multi-Family 2004 2013 40,102 9,042 50,671 1,072 9,042 51,743 60,785 7,933  Alterra at Overlook Ridge II Multi-Family 2008 2013 59,371 12,055 71,409 409 12,056 71,817 83,873 10,980   Projects Under Development  and Developable Land 128,017 363,373 494,764 - 363,373 494,764 858,137 14,726   Furniture, Fixtures  and Equipment - - - 53,718 - 53,718 53,718 15,879   TOTALS 1,406,239 788,528 3,429,551 811,324 807,236 4,498,781 5,306,017 1,097,868    (a) The aggregate cost for federal income tax purposes at December 31, 2018 was approximately $5.1 billion. (b) Depreciation of buildings and improvements are calculated over lives ranging from the life of the lease to 40 years. (c) This property is located on land leased by the Company. (d) Properties identified as held for sale at December 31, 2018 are excluded. (e) These costs are net of impairments and valuation allowances recorded, if any.  MACK-CALI REALTY CORPORATION/MACK-CALI REALTY, L.P. AND SUBSIDIARIES NOTE TO SCHEDULE III    Changes in rental properties and accumulated depreciation for the periods ended December 31, 2018 , 2017 and 2016 are as follows: (dollars in thousands)     2018 2017 2016  Rental Properties  Balance at beginning of year $ 5,102,844 $ 4,804,867 $ 4,807,718  Additions 686,452 1,179,365 819,535  Rental property held for sale (184,233) (310,089) (79,200)  Properties sold (238,873) (538,424) (695,837)  Impairments - - -  Retirements/disposals (60,173) (32,875) (47,349)  Balance at end of year $ 5,306,017 $ 5,102,844 $ 4,804,867    Accumulated Depreciation  Balance at beginning of year $ 1,087,083 $ 1,332,073 $ 1,464,482  Depreciation expense 140,726 154,343 151,569  Rental property held for sale (30,404) (126,503) (31,792)  Properties sold (39,364) (217,625) (204,837)  Repurposed buildings - (22,330) -  Impairments - - -  Retirements/disposals (60,173) (32,875) (47,349)  Balance at end of year $ 1,097,868 $ 1,087,083 $ 1,332,073   Schadf      

Mortgage Loans On Real Estate

Mortgage Loans On Real Estate	12 Months Ended
	Dec. 31, 2018
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]
Mortgages Loans On Real Estate	 MACK-CALI REALTY CORPORATION/MACK-CALI REALTY, L.P. AND SUBSIDIARIES SCHEDULE IV – MORTGAGE LOANS ON REAL ESTATE As of December 31, 2018 (in thousands)       Face Amount  of Mortgages or  Interest Interest Final Periodic Maximum Carrying  Type of Accrual Payment Maturity Payment Prior Available Amount of  Loan/Borrower Description Location Rate Rate Date Term (a) Liens Credit Mortgages   Mortgage Loan:  Borrower A Land Jersey City, NJ 5.85 % 5.85 % 07/21/19 P&I - $ 41,695 $ 45,242   Total $ 41,695 $ 45,242   (a) P&I = Principal & Interest at maturity   The following table reconciles mortgage loans from January 1, 2017 to December 31, 2018 (in thousands) :     2018 2017  Balance at January 1 $ 45,734 $ -  Additions/(repayments)  New mortgage loan/(repayments) (3,000) 44,695  Accrued interest 2,508 1,039  Balance at December 31, $ 45,242 $ 45,734 

Significant Accounting Polici_2

Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Rental Property	Rental Property Rental 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 were expensed as incurred for all real estate acquisitions classified as business combinations, which were substantially all of our operating property acquisitions, through December 31, 2016. The Company early adopted FASB guidance Accounting Standards Update (“ASU”) 2017-01 on January 1, 2017, which revises the definition of a business and is expected to result in more transactions to be accounted for as asset acquisitions and significantly limit transactions that would be accounted for as business combinations. Where an acquisition has been determined to be an asset acquisition, acquisition-related costs are capitalized. 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 $ 2.3 million, $ 2.2 million and $2.6 million for the years ended December 31, 2018 , 2017 and 2016 , 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.  Included in net investment in rental property as of December 31, 2018 and December 31, 2017 is real estate and building and tenant improvements not in service; as follows (dollars in thousands) :     December 31, December 31,  2018 2017  Land held for development (including pre-development costs) (a) $ 465,930 $ 483,432  Development and construction in progress, including land (b) 327,039 535,971  Total $ 792,969 $ 1,019,403  (a) Includes predevelopment and infrastructure costs included in buildings and improvements of $204.9 million and $188.1 million as of December 31, 2018 and December 31, 2017, respectively. (b) Includes land of $49.6 million and $77.0 million as of December 31, 2018 and December 31, 2017, respectively.  The Company considers a construction project as substantially completed and held available for occupancy upon the substantial completion of 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 residents, 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 commercial square footage or multi-family units 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 relative fair values. The Company records goodwill or a gain on bargain purchase (if any) if the net assets acquired/liabilities assumed differ from the purchase consideration of a business 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 or leases.  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, current and historical operating and/or cash flow losses, near-term mortgage debt maturities and/or other factors, including those 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 impairment loss shall be measured as the excess of the carrying value 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 Sale When 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. The Company generally considers assets to be held for sale when the transaction has received appropriate corporate authority, and there are no significant contingencies relating to the sale. If, in management’s opinion, the estimated net sales price, net of selling costs, of the assets which have been identified as held for sale is less than the carrying value of the assets, a valuation allowance (which is recorded as unrealized losses on disposition of rental property) 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 value 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 Ventures The 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.  If the venture subsequently makes distributions and the Company does not have an implied or actual commitment to support the operations of the venture, including a general partner interest in the investee, the Company will not record a basis less than zero, rather such amounts will be recorded as equity in earnings of unconsolidated joint ventures. 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 value 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 Equivalents All highly liquid investments with an original maturity of three months or less when purchased are considered to be cash equivalents.
Deferred Financing Costs	 Deferred Financing Costs Costs incurred in obtaining financing are capitalized and amortized over the term of the related indebtedness. Deferred financing costs are presented in the balance sheet as a direct deduction from the carrying value of the debt liability to which they relate, except deferred financing costs related to the revolving credit facility, which are presented in deferred charges, goodwill and other assets. In all cases, amortization of such costs is included in interest expense and was $ 5,028,000 , $ 4,612,000 and $ 4,582,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. If a financing obligation is extinguished early, any unamortized deferred financing costs are written off and included in gains (losses) from extinguishment of debt. Included in loss from extinguishment of debt, net of gains, of $10.8 million, $0.4 million and $ 30.5 million for the years ended December 31, 2018 , 2017 and 2016 were unamortized deferred financing costs which were written off (as non-cash transactions) amounting to $0.6 million, $ 0.4 million and $ 0.7 million, respectively.
Deferred Leasing Costs	Deferred Leasing Costs Costs incurred in connection with successfully executed commercial and residential 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, and included in deferred charges, goodwill and other assets, net was approximately $ 3,463,000 , $ 3,146,000 and $ 3,270,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. Upon the adoption of ASC842 on January1, 2019, the Company will no longer capitalize such costs.
Goodwill	Goodwill Goodwill 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 value 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 value. If, based on this assessment, management determines that the fair value of the reporting unit is not less than its carrying value, then performing the additional two-step impairment test is unnecessary. If the carrying value of goodwill exceeds its fair value, an impairment charge is recognized. The Company determined that its goodwill, with a balance of $2.9 million, was not impaired at December 31, 2018 after management performed its impairment tests.
Derivative Instruments	Derivative Instruments The 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 Recognition Base 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 Accounts Management 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 Taxes The General Partner has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “IRS Code”). As a REIT, the General Partner generally will not be subject to corporate federal income tax on net income that it currently distributes to its shareholders, provided that the General Partner 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 General Partner retains and does not distribute any net capital gains, the General Partner will be required to pay federal, state and local taxes, as applicable, on such net capital gains at the rate applicable to capital gains of a corporation.  The Operating Partnership is a partnership, and, as a result, all income and losses of the partnership are allocated to the partners for inclusion in their respective tax returns. Accordingly, no provision or benefit for income taxes has been made in the accompanying financial statements.  As of December 31, 2018 , the estimated net basis of the rental property for federal income tax purposes was lower than the net assets as reported in the Operating Partnership’s financial statements by approximately $410,573,000 . The Operating Partnership’s taxable income for the year ended December 31, 2018 was estimated to be approximately $82,106,000 and for the years ended December 31, 2017 and 2016 was approximately $97,037,000 and $30,208,000 , respectively. The differences between book income and taxable income primarily result from differences in depreciation expenses, the recording of rental income, differences in the deductibility of interest expense and certain other expenses for tax purposes, differences in revenue recognition and the rules for tax purposes of a property exchange.  The General Partner has elected to treat certain of its corporate subsidiaries as taxable REIT subsidiaries (each a “TRS”). In general, a TRS of the General Partner 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 General Partner 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.  The deferred tax asset balance at December 31, 2018 amounted to $ 10.1 million which has been fully reserved through a valuation allowance. New tax reform legislation enacted in late 2017 reduced the corporate tax rate to 21 percent, effective January 1, 2018. Consequently, the Company’s deferred tax assets were re-measured to reflect the reduction in the future U.S. corporate income tax rate as of the enactment date. As a result, the Company recorded a decrease related to its deferred tax assets of $5.3 million and a decrease to the associated valuation allowance of $5.3 million at December 31, 2017. If the General Partner fails to qualify as a REIT in any taxable year, the Company will be subject to federal income 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 December 31, 2018 , the tax years that remain subject to examination by the major tax jurisdictions under the statute of limitations are generally from the year 2014 forward. 
Earnings Per Share Or Unit	Earnings Per Share or Unit The Company presents both basic and diluted earnings per share or unit (“EPS or EPU”). Basic EPS or EPU excludes dilution and is computed by dividing net income available to common shareholders or unitholders by the weighted average number of shares or units outstanding for the period. Diluted EPS or EPU 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 or EPU from continuing operations amount. Shares or Units whose issuance is contingent upon the satisfaction of certain conditions shall be considered outstanding and included in the computation of diluted EPS or EPU as follows (i) if all necessary conditions have been satisfied by the end of the period (the events have occurred), those shares or units 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 or units included in diluted EPS or EPU shall be based on the number of shares or units, 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 or units 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 or units shall be included in the denominator of diluted EPS or EPU as of the beginning of the period (or as of the date of the grant, if later). 
Dividends And Distributions Payable	Dividends and Distributions Payable The dividends and distributions payable at December 31, 2018 represents dividends payable to common shareholders ( 90,320,408 shares) and distributions payable to noncontrolling interest unitholders of the Operating Partnership ( 10,174,285 common units and 1,762,170 LTIP units) for all such holders of record as of January 3, 2019 with respect to the fourth quarter 2018 . The fourth quarter 2018 common stock dividends and unit distributions of $ 0.20 per common share, common unit and LTIP unit were approved by the General Partner’s Board of Directors on December 11, 2018 and paid on January 11, 2019 .  The dividends and distributions payable at December 31, 2017 represents dividends payable to common shareholders ( 89,914,658 shares) and distributions payable to noncontrolling interest unitholders of the Operating Partnership ( 10,438,855 common units and 1,230,877 LTIP units) for all such holders of record as of January 3, 2018 with respect to the fourth quarter 2017 . The fourth quarter 2017 common stock dividends and unit distributions of $ 0.20 per common share, common unit and LTIP unit were approved by the General Partner’s Board of Directors on December 12, 2017 and paid on January 12, 2018 .  The Company has determined that the $ 0.80 dividend per common share paid during the year ended December 31, 2018 represented approximately 47 percent ordinary income and approximately 53 percent capital gain; the $ 0.70 dividend per common share paid during the year ended December 31, 2017 represented 100 percent ordinary income and the $ 0.60 dividend per common share paid during the year ended December 31, 2016 represented 100 percent return of capital. 
Costs Incurred For Stock Issuances	Costs Incurred For Stock Issuances Costs incurred in connection with the Company’s stock issuances are reflected as a reduction of additional paid ‑in capital. 
Stock Compensation	Stock Compensation The 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”), performance share units, long term incentive plan awards and stock options at the grant date be amortized ratably into expense over the appropriate vesting period. The Company recorded stock compensation expense of $ 6,894,000 , $ 7,447,000 and $ 5,646,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. 
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) Other comprehensive income (loss) includes items that are recorded in equity, such as effective portions of derivatives designated as cash flow hedges or unrealized holding gains or losses on marketable securities available for sale.
Redeemable Noncontrolling Interests	Redeemable Noncontrolling Interests The Company evaluates the terms of the partnership units issued in accordance with the FASB’s Distinguishing Liabilities from Equity guidance. Units which embody an unconditional obligation requiring the Company to redeem the units for cash after a specified or determinable date (or dates) or upon the occurrence of an event that is not solely within the control of the issuer are determined to be contingently redeemable under this guidance and are included as Redeemable noncontrolling interests and classified within the mezzanine section between Total liabilities and Stockholders’ equity on the Company’s Consolidated Balance Sheets. The carrying amount of the redeemable noncontrolling interests will be changed by periodic accretions, so that the carrying amount will equal the estimated future redemption value at the redemption date.
Fair Value Hierarchy	Fair Value Hierarchy The 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.
Impact Of Recently-Issued Accounting Standards	Impact Of Recently-Issued Accounting Standards In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), modifying the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). ASU 2016-02 provides new guidelines that change the accounting for leasing arrangements for lessees, whereby their rights and obligations under substantially all leases, existing and new, would be capitalized and recorded on the balance sheet. For lessors, however, the accounting remains largely equivalent to the current model, with the distinction between operating, sales-type, and direct financing leases retained, but updated to align with certain changes to the lessee model and the new revenue recognition standard.  ASU 2016-02 provides two transition methods. The first transition method allows for application of the new model at the beginning of the earliest comparative period presented. Under the second transition method, comparative periods would not be restated, with any cumulative effect adjustments recognized in the opening balance of retained earnings in the period of adoption. In addition, a practical expedient was recently issued by the FASB that allows lessors to combine non-lease components with related lease components if certain conditions are met. The Company will adopt this guidance for its interim and annual periods beginning January 1, 2019 and expects to use the second transition method.  Under ASU 2016-02, lessors will only capitalize incremental direct leasing costs and will expense internal leasing costs that were previously capitalized prior to the adoption of ASU 2016-02. For leases where the Company is a lessee, primarily its ground leases, the Company expects to recognize a right-of-use asset and a corresponding lease liability. The Company is continuing to assess the potential impact of this standard but expects to recognize right-of-use assets and lease liabilities for such ground leases.  In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (“ASU 2016-13”). The guidance introduces a new model for estimating credit losses for certain types of financial instruments, including trade and lease receivables, loans receivable, held-to-maturity debt securities, and net investments in direct financing leases, amongst other financial instruments. ASU 2016-13 also modifies the impairment model for available-for-sale debt securities and expands the disclosure requirements regarding an entity’s assumptions, models, and methods for estimating the allowance for losses. ASU 2016-13 is effective for annual reporting periods beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. The Company is currently in the process of evaluating the impact the adoption of ASU 2016-13 will have on the Company’s consolidated financial statements.  In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities (“ASU 2017-12”). The purpose of ASU 2017-12 is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. ASU 2017-12 is effective for annual reporting periods beginning after December 15, 2018. ASU 2017-12 requires a modified retrospective transition method which requires a cumulative effect of the change on the opening balance of each affected component of equity in the Company’s consolidated financial statements as of the date of adoption. The Company does not expect the adoption of ASU 2017-12 to have a material impact on the Company’s consolidated financial statements.
Mack-Cali Realty LP [Member]
Significant Accounting Policies [Line Items]
Rental Property	Rental Property Rental 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 were expensed as incurred for all real estate acquisitions classified as business combinations, which were substantially all of our operating property acquisitions, through December 31, 2016. The Company early adopted FASB guidance Accounting Standards Update (“ASU”) 2017-01 on January 1, 2017, which revises the definition of a business and is expected to result in more transactions to be accounted for as asset acquisitions and significantly limit transactions that would be accounted for as business combinations. Where an acquisition has been determined to be an asset acquisition, acquisition-related costs are capitalized. 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 $ 2.3 million, $ 2.2 million and $2.6 million for the years ended December 31, 2018 , 2017 and 2016 , 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.  Included in net investment in rental property as of December 31, 2018 and December 31, 2017 is real estate and building and tenant improvements not in service; as follows (dollars in thousands) :     December 31, December 31,  2018 2017  Land held for development (including pre-development costs) (a) $ 465,930 $ 483,432  Development and construction in progress, including land (b) 327,039 535,971  Total $ 792,969 $ 1,019,403  (a) Includes predevelopment and infrastructure costs included in buildings and improvements of $204.9 million and $188.1 million as of December 31, 2018 and December 31, 2017, respectively. (b) Includes land of $49.6 million and $77.0 million as of December 31, 2018 and December 31, 2017, respectively.  The Company considers a construction project as substantially completed and held available for occupancy upon the substantial completion of 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 residents, 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 commercial square footage or multi-family units 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 relative fair values. The Company records goodwill or a gain on bargain purchase (if any) if the net assets acquired/liabilities assumed differ from the purchase consideration of a business 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 or leases.  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, current and historical operating and/or cash flow losses, near-term mortgage debt maturities and/or other factors, including those 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 impairment loss shall be measured as the excess of the carrying value 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 Sale When 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. The Company generally considers assets to be held for sale when the transaction has received appropriate corporate authority, and there are no significant contingencies relating to the sale. If, in management’s opinion, the estimated net sales price, net of selling costs, of the assets which have been identified as held for sale is less than the carrying value of the assets, a valuation allowance (which is recorded as unrealized losses on disposition of rental property) 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 value 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 Ventures The 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.  If the venture subsequently makes distributions and the Company does not have an implied or actual commitment to support the operations of the venture, including a general partner interest in the investee, the Company will not record a basis less than zero, rather such amounts will be recorded as equity in earnings of unconsolidated joint ventures. 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 value 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 Equivalents All highly liquid investments with an original maturity of three months or less when purchased are considered to be cash equivalents.
Deferred Financing Costs	 Deferred Financing Costs Costs incurred in obtaining financing are capitalized and amortized over the term of the related indebtedness. Deferred financing costs are presented in the balance sheet as a direct deduction from the carrying value of the debt liability to which they relate, except deferred financing costs related to the revolving credit facility, which are presented in deferred charges, goodwill and other assets. In all cases, amortization of such costs is included in interest expense and was $ 5,028,000 , $ 4,612,000 and $ 4,582,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. If a financing obligation is extinguished early, any unamortized deferred financing costs are written off and included in gains (losses) from extinguishment of debt. Included in loss from extinguishment of debt, net of gains, of $10.8 million, $0.4 million and $ 30.5 million for the years ended December 31, 2018 , 2017 and 2016 were unamortized deferred financing costs which were written off (as non-cash transactions) amounting to $0.6 million, $ 0.4 million and $ 0.7 million, respectively.
Deferred Leasing Costs	Deferred Leasing Costs Costs incurred in connection with successfully executed commercial and residential 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, and included in deferred charges, goodwill and other assets, net was approximately $ 3,463,000 , $ 3,146,000 and $ 3,270,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. Upon the adoption of ASC842 on January1, 2019, the Company will no longer capitalize such costs.
Goodwill	Goodwill Goodwill 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 value 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 value. If, based on this assessment, management determines that the fair value of the reporting unit is not less than its carrying value, then performing the additional two-step impairment test is unnecessary. If the carrying value of goodwill exceeds its fair value, an impairment charge is recognized. The Company determined that its goodwill, with a balance of $2.9 million, was not impaired at December 31, 2018 after management performed its impairment tests.
Derivative Instruments	Derivative Instruments The 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 Recognition Base 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 Accounts Management 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 Taxes The General Partner has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “IRS Code”). As a REIT, the General Partner generally will not be subject to corporate federal income tax on net income that it currently distributes to its shareholders, provided that the General Partner 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 General Partner retains and does not distribute any net capital gains, the General Partner will be required to pay federal, state and local taxes, as applicable, on such net capital gains at the rate applicable to capital gains of a corporation.  The Operating Partnership is a partnership, and, as a result, all income and losses of the partnership are allocated to the partners for inclusion in their respective tax returns. Accordingly, no provision or benefit for income taxes has been made in the accompanying financial statements.  As of December 31, 2018 , the estimated net basis of the rental property for federal income tax purposes was lower than the net assets as reported in the Operating Partnership’s financial statements by approximately $410,573,000 . The Operating Partnership’s taxable income for the year ended December 31, 2018 was estimated to be approximately $82,106,000 and for the years ended December 31, 2017 and 2016 was approximately $97,037,000 and $30,208,000 , respectively. The differences between book income and taxable income primarily result from differences in depreciation expenses, the recording of rental income, differences in the deductibility of interest expense and certain other expenses for tax purposes, differences in revenue recognition and the rules for tax purposes of a property exchange.  The General Partner has elected to treat certain of its corporate subsidiaries as taxable REIT subsidiaries (each a “TRS”). In general, a TRS of the General Partner 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 General Partner 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.  The deferred tax asset balance at December 31, 2018 amounted to $ 10.1 million which has been fully reserved through a valuation allowance. New tax reform legislation enacted in late 2017 reduced the corporate tax rate to 21 percent, effective January 1, 2018. Consequently, the Company’s deferred tax assets were re-measured to reflect the reduction in the future U.S. corporate income tax rate as of the enactment date. As a result, the Company recorded a decrease related to its deferred tax assets of $5.3 million and a decrease to the associated valuation allowance of $5.3 million at December 31, 2017. If the General Partner fails to qualify as a REIT in any taxable year, the Company will be subject to federal income 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 December 31, 2018 , the tax years that remain subject to examination by the major tax jurisdictions under the statute of limitations are generally from the year 2014 forward. 
Earnings Per Share Or Unit	Earnings Per Share or Unit The Company presents both basic and diluted earnings per share or unit (“EPS or EPU”). Basic EPS or EPU excludes dilution and is computed by dividing net income available to common shareholders or unitholders by the weighted average number of shares or units outstanding for the period. Diluted EPS or EPU 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 or EPU from continuing operations amount. Shares or Units whose issuance is contingent upon the satisfaction of certain conditions shall be considered outstanding and included in the computation of diluted EPS or EPU as follows (i) if all necessary conditions have been satisfied by the end of the period (the events have occurred), those shares or units 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 or units included in diluted EPS or EPU shall be based on the number of shares or units, 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 or units 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 or units shall be included in the denominator of diluted EPS or EPU as of the beginning of the period (or as of the date of the grant, if later). 
Dividends And Distributions Payable	Dividends and Distributions Payable The dividends and distributions payable at December 31, 2018 represents dividends payable to common shareholders ( 90,320,408 shares) and distributions payable to noncontrolling interest unitholders of the Operating Partnership ( 10,174,285 common units and 1,762,170 LTIP units) for all such holders of record as of January 3, 2019 with respect to the fourth quarter 2018 . The fourth quarter 2018 common stock dividends and unit distributions of $ 0.20 per common share, common unit and LTIP unit were approved by the General Partner’s Board of Directors on December 11, 2018 and paid on January 11, 2019 .  The dividends and distributions payable at December 31, 2017 represents dividends payable to common shareholders ( 89,914,658 shares) and distributions payable to noncontrolling interest unitholders of the Operating Partnership ( 10,438,855 common units and 1,230,877 LTIP units) for all such holders of record as of January 3, 2018 with respect to the fourth quarter 2017 . The fourth quarter 2017 common stock dividends and unit distributions of $ 0.20 per common share, common unit and LTIP unit were approved by the General Partner’s Board of Directors on December 12, 2017 and paid on January 12, 2018 .  The Company has determined that the $ 0.80 dividend per common share paid during the year ended December 31, 2018 represented approximately 47 percent ordinary income and approximately 53 percent capital gain; the $ 0.70 dividend per common share paid during the year ended December 31, 2017 represented 100 percent ordinary income and the $ 0.60 dividend per common share paid during the year ended December 31, 2016 represented 100 percent return of capital. 
Costs Incurred For Stock Issuances	Costs Incurred For Stock Issuances Costs incurred in connection with the Company’s stock issuances are reflected as a reduction of additional paid ‑in capital. 
Stock Compensation	Stock Compensation The 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”), performance share units, long term incentive plan awards and stock options at the grant date be amortized ratably into expense over the appropriate vesting period. The Company recorded stock compensation expense of $ 6,894,000 , $ 7,447,000 and $ 5,646,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. 
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) Other comprehensive income (loss) includes items that are recorded in equity, such as effective portions of derivatives designated as cash flow hedges or unrealized holding gains or losses on marketable securities available for sale.
Redeemable Noncontrolling Interests	Redeemable Noncontrolling Interests The Company evaluates the terms of the partnership units issued in accordance with the FASB’s Distinguishing Liabilities from Equity guidance. Units which embody an unconditional obligation requiring the Company to redeem the units for cash after a specified or determinable date (or dates) or upon the occurrence of an event that is not solely within the control of the issuer are determined to be contingently redeemable under this guidance and are included as Redeemable noncontrolling interests and classified within the mezzanine section between Total liabilities and Stockholders’ equity on the Company’s Consolidated Balance Sheets. The carrying amount of the redeemable noncontrolling interests will be changed by periodic accretions, so that the carrying amount will equal the estimated future redemption value at the redemption date.
Fair Value Hierarchy	Fair Value Hierarchy The 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.
Impact Of Recently-Issued Accounting Standards	Impact Of Recently-Issued Accounting Standards In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), modifying the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). ASU 2016-02 provides new guidelines that change the accounting for leasing arrangements for lessees, whereby their rights and obligations under substantially all leases, existing and new, would be capitalized and recorded on the balance sheet. For lessors, however, the accounting remains largely equivalent to the current model, with the distinction between operating, sales-type, and direct financing leases retained, but updated to align with certain changes to the lessee model and the new revenue recognition standard.  ASU 2016-02 provides two transition methods. The first transition method allows for application of the new model at the beginning of the earliest comparative period presented. Under the second transition method, comparative periods would not be restated, with any cumulative effect adjustments recognized in the opening balance of retained earnings in the period of adoption. In addition, a practical expedient was recently issued by the FASB that allows lessors to combine non-lease components with related lease components if certain conditions are met. The Company will adopt this guidance for its interim and annual periods beginning January 1, 2019 and expects to use the second transition method.  Under ASU 2016-02, lessors will only capitalize incremental direct leasing costs and will expense internal leasing costs that were previously capitalized prior to the adoption of ASU 2016-02. For leases where the Company is a lessee, primarily its ground leases, the Company expects to recognize a right-of-use asset and a corresponding lease liability. The Company is continuing to assess the potential impact of this standard but expects to recognize right-of-use assets and lease liabilities for such ground leases.  In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (“ASU 2016-13”). The guidance introduces a new model for estimating credit losses for certain types of financial instruments, including trade and lease receivables, loans receivable, held-to-maturity debt securities, and net investments in direct financing leases, amongst other financial instruments. ASU 2016-13 also modifies the impairment model for available-for-sale debt securities and expands the disclosure requirements regarding an entity’s assumptions, models, and methods for estimating the allowance for losses. ASU 2016-13 is effective for annual reporting periods beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. The Company is currently in the process of evaluating the impact the adoption of ASU 2016-13 will have on the Company’s consolidated financial statements.  In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities (“ASU 2017-12”). The purpose of ASU 2017-12 is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. ASU 2017-12 is effective for annual reporting periods beginning after December 15, 2018. ASU 2017-12 requires a modified retrospective transition method which requires a cumulative effect of the change on the opening balance of each affected component of equity in the Company’s consolidated financial statements as of the date of adoption. The Company does not expect the adoption of ASU 2017-12 to have a material impact on the Company’s consolidated financial statements.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Schedule Of Rental Property Improvements	   December 31, December 31,  2018 2017  Land held for development (including pre-development costs) (a) $ 465,930 $ 483,432  Development and construction in progress, including land (b) 327,039 535,971  Total $ 792,969 $ 1,019,403  (a) Includes predevelopment and infrastructure costs included in buildings and improvements of $204.9 million and $188.1 million as of December 31, 2018 and December 31, 2017, respectively. (b) Includes land of $49.6 million and $77.0 million as of December 31, 2018 and December 31, 2017, respectively. 
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 
Mack-Cali Realty LP [Member]
Significant Accounting Policies [Line Items]
Schedule Of Rental Property Improvements	   December 31, December 31,  2018 2017  Land held for development (including pre-development costs) (a) $ 465,930 $ 483,432  Development and construction in progress, including land (b) 327,039 535,971  Total $ 792,969 $ 1,019,403  (a) Includes predevelopment and infrastructure costs included in buildings and improvements of $204.9 million and $188.1 million as of December 31, 2018 and December 31, 2017, respectively. (b) Includes land of $49.6 million and $77.0 million as of December 31, 2018 and December 31, 2017, respectively. 
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 

Recent Transactions (Tables)

Recent Transactions (Tables)	12 Months Ended
	Dec. 31, 2018
Real Estate Properties [Line Items]
Schedule Of Properties Acquired	   Acquisition # of Rentable Acquisition  Date Property Address Location Bldgs. Square Feet Cost  01/11/17 Red Bank portfolio (a) Red Bank, New Jersey 3 279,472 $ 27,228  03/06/17 Short Hills/Madison portfolio (b) Short Hills & Madison, New Jersey 6 1,113,028 367,361   Total Acquisitions 9 1,392,500 $ 394,589   (a) This acquisition was funded through borrowings under the Company's unsecured revolving credit facility.  (b) This acquisition was funded through borrowings under the Company’s unsecured revolving credit facility and a new $124.5 million loan secured by three of the properties. 
Schedule Of Purchase Price Allocation	   Red Bank Short Hills/Madison  Portfolio Portfolio Total  Land and leasehold interest $ 7,914 $ 30,336 $ 38,250  Buildings and improvements and other assets 16,047 295,299 311,346  Above market leases (a) 118 6,367 6,485  In-place lease values (a) 3,171 45,604 48,775  27,250 377,606 404,856  Less: Below market lease values (a) (22) (10,245) (10,267)  Net assets recorded upon acquisition $ 27,228 $ 367,361 $ 394,589  (a) Above market, in-place and below market leases are being amortized over a weighted-average term of 5.4 years.
Schedule Of Properties Which Commenced Initial Operations	   # of Total  In-Service Apartment Units/ Development  Date Property Location Type Rooms Costs Incurred  03/01/18 145 Front at City Square Worcester, MA Multi-Family 365 $ 97,483 (a)  04/01/18 Signature Place at Morris Plains Morris Plains, NJ Multi-Family 197 56,715 (b)  05/01/18 Portside 5/6 East Boston, MA Multi-Family 296 114,694 (c)  08/01/18 RiverHouse 11 at Port Imperial Weehawken, NJ Multi-Family 295 130,369 (d)  12/13/18 Residence Inn By Marriott (Phase I) Weehawken, NJ Hotel 164 58,723 (e)  Totals 1,317 $ 457,984 (a) Development costs as of December 31, 2018 included approximately $4.4 in land costs. As of December 31, 2018, the Company anticipates additional costs of approximately $1.1 million, which will be primarily funded from a construction loan. (b) Development costs as of December 31, 2018 included approximately $0.9 in land costs. (c) As of December 31, 2018 , the Company anticipates additional costs of approximately $0.7 million, which will be funded by the Company. (d) As of December 31, 2018 , the Company anticipates additional costs of $1.2 million which will be funded by the Company. (e) As of December 31, 2018, the Company anticipates additional costs of $20.1 million which will be funded from a construction loan.
Schedule Of Net Assets Recorded Upon Consolidation	2018     Marbella Land and leasehold interest $ 48,820 Buildings and improvements and other assets, net 162,958 In-place lease values (a) 6,947 Less: Below market lease values (a) (108)  218,617 Less: Debt (131,000) Net Assets 87,617 Less: Noncontrolling interest (b) (22,812) Net assets recorded upon consolidation $ 64,805  (a) In-place and below market leases are being amortized over a weighted-average term of 9.3 months. (b) Noncontrolling interest balance reflects distribution of $7.0 million of loan proceeds at closing.   2017    Monaco Monaco  North South Total Land and leasehold interest $ 27,300 $ 31,461 $ 58,761 Buildings and improvements and other assets 112,841 129,895 242,736 Above market leases (a) 350 - 350 In-place lease values (a) 4,585 4,913 9,498 Less: Below market lease values (a) (141) (118) (259)  144,935 166,151 311,086 Less: Debt assumed at fair value (79,544) (91,656) (171,200) Net assets recorded upon consolidation $ 65,391 $ 74,495 $ 139,886  (a) Above market, in-place and below market leases are being amortized over a weighted-average term of 8 months.
Schedule Of Disposed Properties	 2018 The Company disposed of the following office properties during the year ended December 31, 2018 (dollars in thousands) :     Realized  Gains  Rentable Net Net (losses)/ Disposition # of Square Sales Carrying Unrealized Date Property/Address Location Bldgs. Feet Proceeds Value Losses, net 02/15/18 35 Waterview Boulevard (a) Parsippany, New Jersey 1 172,498 $ 25,994 $ 25,739 $ 255 03/05/18 Hamilton portfolio (b) Hamilton, New Jersey 6 239,262 17,546 17,501 45 03/07/18 Wall portfolio first closing Wall, New Jersey 5 179,601 14,053 10,526 3,527 03/22/18 700 Horizon Drive Hamilton, New Jersey 1 120,000 33,020 16,053 16,967 03/23/18 Wall portfolio second closing Wall, New Jersey 3 217,822 30,209 12,961 17,248 03/28/18 75 Livingston Avenue Roseland, New Jersey 1 94,221 7,983 5,609 2,374 03/28/18 20 Waterview Boulevard (c) Parsippany, New Jersey 1 225,550 12,475 11,795 680 03/30/18 Westchester Financial Center (d) White Plains, New York 2 489,000 81,769 64,679 17,090 06/27/18 65 Jackson Drive Cranford, New Jersey 0 - 1,510 (e) - 1,510 08/02/18 600 Horizon Drive Hamilton, New Jersey 1 95,000 15,127 6,191 8,936 09/05/18 1 & 3 Barker Avenue White Plains, New York 2 133,300 15,140 13,543 1,597 11/15/18 120 Passaic Street (f) Rochelle Park, New Jersey 1 52,000 2,667 2,568 99 12/31/18 Elmsford Distribution Center Elmsford, New York 6 387,400 66,557 17,314 49,243 Sub-total 30 2,405,654 324,050 204,479 119,571  Unrealized losses on rental property held for sale (20,135) Totals 30 2,405,654 $ 324,050 $ 204,479 $ 99,436  (a) The Company recorded a valuation allowance of $0.7 million on this property during the year ended December 31, 2017. (b) The Company recorded a valuation allowance of $0.6 million on these properties during the year ended December 31, 2017. The disposition additionally included two land properties. (c) The Company recorded a valuation allowance of $11 million on this property during the year ended December 31, 2017. Prior to closing, the Company provided short term financing through a note receivable to an affiliate of the buyers of $2.8 million. The note was paid off in the second quarter of 2018. (d) Prior to closing, the Company provided financing through a note receivable to an affiliate of the buyers of $4.0 million. The note was paid off in October 2018. (e) Represents the receipt by the Company in the second quarter 2018 of variable contingent sales consideration, net of costs, of $1.5 million subsequent to disposition of the property sold in January 2017. (f) The net sale proceeds were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2018. See Note 5: Deferred Charges, Goodwill and Other Assets, Net).   2017 The Company disposed of the following office properties during the year ended December 31, 2017 (dollars in thousands) :     Realized  Gains  Rentable Net Net (losses)/ Disposition # of Square Sales Carrying Unrealized Date Property/Address Location Bldgs. Feet Proceeds Value Losses, net 01/30/17 Cranford portfolio Cranford, New Jersey 6 435,976 $ 26,598 $ 22,736 $ 3,862 01/31/17 440 Route 22 East (a) Bridgewater, New Jersey 1 198,376 10,074 10,069 5 02/07/17 3 Independence Way Princeton, New Jersey 1 111,300 11,549 9,910 1,639 05/15/17 103 Carnegie Center Princeton, New Jersey 1 96,000 15,063 8,271 6,792 08/29/17 400 Chestnut Ridge Road Woodcliff Lake, New Jersey 1 89,200 6,891 7,498 (607) 08/30/17 140 E. Ridgewood Avenue Paramus, New Jersey 1 239,680 30,201 30,737 (536) 08/30/17 Bergen portfolio Woodcliff Lake, Paramus and 5 1,061,544 86,973 (c) 135,121 (48,148)  Rochelle Park, New Jersey 09/11/17 377 Summerhill Road East Brunswick, New Jersey 1 40,000 3,221 2,172 1,049 09/13/17 700 Executive Boulevard Elmsford, New York - - (b) 5,717 970 4,747 09/20/17 Totowa Portfolio Totowa, New Jersey 13 499,243 63,624 27,630 35,994 09/27/17 890 Mountain Avenue (d) New Providence, New Jersey 1 80,000 4,852 6,139 (1,287) 09/28/17 135 Chestnut Ridge Road Montvale, New Jersey 1 66,150 5,844 (e) 2,929 2,915 09/29/17 Moorestown portfolio Moorestown and Burlington, New Jersey 26 1,260,398 73,393 (f) 56,186 17,207 10/19/17 1 Enterprise Boulevard Yonkers, New York - - (b) 3,230 1,380 1,850 11/15/17 61 South Paramus Road Paramus, New Jersey 1 269,191 23,255 37,184 (13,929) 12/06/17 300 Tice Boulevard Woodcliff Lake, New Jersey 1 230,000 28,847 25,705 3,142 Sub-total 60 4,677,058 399,332 384,637 14,695  Unrealized losses on rental property held for sale (12,331)  Totals 60 4,677,058 $ 399,332 $ 384,637 $ 2,364  (a) The Company recorded a valuation allowance of $7.7 million on this property during the year ended December 31, 2016. (b) This disposition is of a ground leased land property. (c) At closing, the Company provided short term seller financing aggregating $65 million through mortgage notes receivable to the buyers. These notes were paid off in November and December 2017. (d) The Company recorded an impairment charge of $7.0 million on this property during the year ended December 31, 2015. (e) The Company recorded an impairment charge of $4.2 million on this property during the year ended December 31, 2015. $5.9 million of the sales proceeds from this sale were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2017. See Note 5: Deferred Charges, Goodwill and Other Assets, Net. (f) $15.3 million of the sales proceeds from this sale were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2017. See Note 5: Deferred Charges, Goodwill and Other Assets, Net.  
Schedule Of Disposed Developable Land	   Net Net Gain on  Disposition Sales Carrying Disposition of  Date Property Address Location Proceeds Value Developable Land  12/31/18 One Lake Street Upper Saddle River, New Jersey (a) $ 46,036 $ 15,097 $ 30,939   Totals $ 46,036 $ 15,097 $ 30,939   (a) The net sale proceeds were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2018. See Note 5: Deferred  Charges, Goodwill and Other Assets, Net. The net carrying value includes $3 million of development costs funded at the closing. 
Summary Of Income From Property Held For Sale, Net	The following table summarizes the rental property held for sale, net, as of December 31, 2018 (dollars in thousands):     December 31,  2018 Land $ 24,376 Buildings and improvements 159,857 Less: Accumulated depreciation (55,250) Less: Unrealized losses on properties held for sale (20,135) Rental property held for sale, net $ 108,848  The following table summarizes the rental property held for sale, net, as of December 31, 2017 (dollars in thousands):     December 31,  2017 Land $ 37,024 Buildings and improvements 273,388 Less: Accumulated depreciation (126,503) Less: Unrealized losses on properties held for sale (12,331) Rental property held for sale,net $ 171,578  
Mack-Cali Realty LP [Member]
Real Estate Properties [Line Items]
Schedule Of Properties Acquired	   Acquisition # of Rentable Acquisition  Date Property Address Location Bldgs. Square Feet Cost  01/11/17 Red Bank portfolio (a) Red Bank, New Jersey 3 279,472 $ 27,228  03/06/17 Short Hills/Madison portfolio (b) Short Hills & Madison, New Jersey 6 1,113,028 367,361   Total Acquisitions 9 1,392,500 $ 394,589   (a) This acquisition was funded through borrowings under the Company's unsecured revolving credit facility.  (b) This acquisition was funded through borrowings under the Company’s unsecured revolving credit facility and a new $124.5 million loan secured by three of the properties. 
Schedule Of Purchase Price Allocation	   Red Bank Short Hills/Madison  Portfolio Portfolio Total  Land and leasehold interest $ 7,914 $ 30,336 $ 38,250  Buildings and improvements and other assets 16,047 295,299 311,346  Above market leases (a) 118 6,367 6,485  In-place lease values (a) 3,171 45,604 48,775  27,250 377,606 404,856  Less: Below market lease values (a) (22) (10,245) (10,267)  Net assets recorded upon acquisition $ 27,228 $ 367,361 $ 394,589  (a) Above market, in-place and below market leases are being amortized over a weighted-average term of 5.4 years.
Schedule Of Properties Which Commenced Initial Operations	   # of Total  In-Service Apartment Units/ Development  Date Property Location Type Rooms Costs Incurred  03/01/18 145 Front at City Square Worcester, MA Multi-Family 365 $ 97,483 (a)  04/01/18 Signature Place at Morris Plains Morris Plains, NJ Multi-Family 197 56,715 (b)  05/01/18 Portside 5/6 East Boston, MA Multi-Family 296 114,694 (c)  08/01/18 RiverHouse 11 at Port Imperial Weehawken, NJ Multi-Family 295 130,369 (d)  12/13/18 Residence Inn By Marriott (Phase I) Weehawken, NJ Hotel 164 58,723 (e)  Totals 1,317 $ 457,984 (a) Development costs as of December 31, 2018 included approximately $4.4 in land costs. As of December 31, 2018, the Company anticipates additional costs of approximately $1.1 million, which will be primarily funded from a construction loan. (b) Development costs as of December 31, 2018 included approximately $0.9 in land costs. (c) As of December 31, 2018 , the Company anticipates additional costs of approximately $0.7 million, which will be funded by the Company. (d) As of December 31, 2018 , the Company anticipates additional costs of $1.2 million which will be funded by the Company. (e) As of December 31, 2018, the Company anticipates additional costs of $20.1 million which will be funded from a construction loan.
Schedule Of Net Assets Recorded Upon Consolidation	2018     Marbella Land and leasehold interest $ 48,820 Buildings and improvements and other assets, net 162,958 In-place lease values (a) 6,947 Less: Below market lease values (a) (108)  218,617 Less: Debt (131,000) Net Assets 87,617 Less: Noncontrolling interest (b) (22,812) Net assets recorded upon consolidation $ 64,805  (a) In-place and below market leases are being amortized over a weighted-average term of 9.3 months. (b) Noncontrolling interest balance reflects distribution of $7.0 million of loan proceeds at closing.   2017    Monaco Monaco  North South Total Land and leasehold interest $ 27,300 $ 31,461 $ 58,761 Buildings and improvements and other assets 112,841 129,895 242,736 Above market leases (a) 350 - 350 In-place lease values (a) 4,585 4,913 9,498 Less: Below market lease values (a) (141) (118) (259)  144,935 166,151 311,086 Less: Debt assumed at fair value (79,544) (91,656) (171,200) Net assets recorded upon consolidation $ 65,391 $ 74,495 $ 139,886  (a) Above market, in-place and below market leases are being amortized over a weighted-average term of 8 months.
Schedule Of Disposed Properties	 2018 The Company disposed of the following office properties during the year ended December 31, 2018 (dollars in thousands) :     Realized  Gains  Rentable Net Net (losses)/ Disposition # of Square Sales Carrying Unrealized Date Property/Address Location Bldgs. Feet Proceeds Value Losses, net 02/15/18 35 Waterview Boulevard (a) Parsippany, New Jersey 1 172,498 $ 25,994 $ 25,739 $ 255 03/05/18 Hamilton portfolio (b) Hamilton, New Jersey 6 239,262 17,546 17,501 45 03/07/18 Wall portfolio first closing Wall, New Jersey 5 179,601 14,053 10,526 3,527 03/22/18 700 Horizon Drive Hamilton, New Jersey 1 120,000 33,020 16,053 16,967 03/23/18 Wall portfolio second closing Wall, New Jersey 3 217,822 30,209 12,961 17,248 03/28/18 75 Livingston Avenue Roseland, New Jersey 1 94,221 7,983 5,609 2,374 03/28/18 20 Waterview Boulevard (c) Parsippany, New Jersey 1 225,550 12,475 11,795 680 03/30/18 Westchester Financial Center (d) White Plains, New York 2 489,000 81,769 64,679 17,090 06/27/18 65 Jackson Drive Cranford, New Jersey 0 - 1,510 (e) - 1,510 08/02/18 600 Horizon Drive Hamilton, New Jersey 1 95,000 15,127 6,191 8,936 09/05/18 1 & 3 Barker Avenue White Plains, New York 2 133,300 15,140 13,543 1,597 11/15/18 120 Passaic Street (f) Rochelle Park, New Jersey 1 52,000 2,667 2,568 99 12/31/18 Elmsford Distribution Center Elmsford, New York 6 387,400 66,557 17,314 49,243 Sub-total 30 2,405,654 324,050 204,479 119,571  Unrealized losses on rental property held for sale (20,135) Totals 30 2,405,654 $ 324,050 $ 204,479 $ 99,436  (a) The Company recorded a valuation allowance of $0.7 million on this property during the year ended December 31, 2017. (b) The Company recorded a valuation allowance of $0.6 million on these properties during the year ended December 31, 2017. The disposition additionally included two land properties. (c) The Company recorded a valuation allowance of $11 million on this property during the year ended December 31, 2017. Prior to closing, the Company provided short term financing through a note receivable to an affiliate of the buyers of $2.8 million. The note was paid off in the second quarter of 2018. (d) Prior to closing, the Company provided financing through a note receivable to an affiliate of the buyers of $4.0 million. The note was paid off in October 2018. (e) Represents the receipt by the Company in the second quarter 2018 of variable contingent sales consideration, net of costs, of $1.5 million subsequent to disposition of the property sold in January 2017. (f) The net sale proceeds were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2018. See Note 5: Deferred Charges, Goodwill and Other Assets, Net).   2017 The Company disposed of the following office properties during the year ended December 31, 2017 (dollars in thousands) :     Realized  Gains  Rentable Net Net (losses)/ Disposition # of Square Sales Carrying Unrealized Date Property/Address Location Bldgs. Feet Proceeds Value Losses, net 01/30/17 Cranford portfolio Cranford, New Jersey 6 435,976 $ 26,598 $ 22,736 $ 3,862 01/31/17 440 Route 22 East (a) Bridgewater, New Jersey 1 198,376 10,074 10,069 5 02/07/17 3 Independence Way Princeton, New Jersey 1 111,300 11,549 9,910 1,639 05/15/17 103 Carnegie Center Princeton, New Jersey 1 96,000 15,063 8,271 6,792 08/29/17 400 Chestnut Ridge Road Woodcliff Lake, New Jersey 1 89,200 6,891 7,498 (607) 08/30/17 140 E. Ridgewood Avenue Paramus, New Jersey 1 239,680 30,201 30,737 (536) 08/30/17 Bergen portfolio Woodcliff Lake, Paramus and 5 1,061,544 86,973 (c) 135,121 (48,148)  Rochelle Park, New Jersey 09/11/17 377 Summerhill Road East Brunswick, New Jersey 1 40,000 3,221 2,172 1,049 09/13/17 700 Executive Boulevard Elmsford, New York - - (b) 5,717 970 4,747 09/20/17 Totowa Portfolio Totowa, New Jersey 13 499,243 63,624 27,630 35,994 09/27/17 890 Mountain Avenue (d) New Providence, New Jersey 1 80,000 4,852 6,139 (1,287) 09/28/17 135 Chestnut Ridge Road Montvale, New Jersey 1 66,150 5,844 (e) 2,929 2,915 09/29/17 Moorestown portfolio Moorestown and Burlington, New Jersey 26 1,260,398 73,393 (f) 56,186 17,207 10/19/17 1 Enterprise Boulevard Yonkers, New York - - (b) 3,230 1,380 1,850 11/15/17 61 South Paramus Road Paramus, New Jersey 1 269,191 23,255 37,184 (13,929) 12/06/17 300 Tice Boulevard Woodcliff Lake, New Jersey 1 230,000 28,847 25,705 3,142 Sub-total 60 4,677,058 399,332 384,637 14,695  Unrealized losses on rental property held for sale (12,331)  Totals 60 4,677,058 $ 399,332 $ 384,637 $ 2,364  (a) The Company recorded a valuation allowance of $7.7 million on this property during the year ended December 31, 2016. (b) This disposition is of a ground leased land property. (c) At closing, the Company provided short term seller financing aggregating $65 million through mortgage notes receivable to the buyers. These notes were paid off in November and December 2017. (d) The Company recorded an impairment charge of $7.0 million on this property during the year ended December 31, 2015. (e) The Company recorded an impairment charge of $4.2 million on this property during the year ended December 31, 2015. $5.9 million of the sales proceeds from this sale were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2017. See Note 5: Deferred Charges, Goodwill and Other Assets, Net. (f) $15.3 million of the sales proceeds from this sale were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2017. See Note 5: Deferred Charges, Goodwill and Other Assets, Net.  
Schedule Of Disposed Developable Land	   Net Net Gain on  Disposition Sales Carrying Disposition of  Date Property Address Location Proceeds Value Developable Land  12/31/18 One Lake Street Upper Saddle River, New Jersey (a) $ 46,036 $ 15,097 $ 30,939   Totals $ 46,036 $ 15,097 $ 30,939   (a) The net sale proceeds were held by a qualified intermediary, which is noncash and recorded in deferred charges, goodwill and other assets as of December 31, 2018. See Note 5: Deferred  Charges, Goodwill and Other Assets, Net. The net carrying value includes $3 million of development costs funded at the closing. 
Summary Of Income From Property Held For Sale, Net	The following table summarizes the rental property held for sale, net, as of December 31, 2018 (dollars in thousands):     December 31,  2018 Land $ 24,376 Buildings and improvements 159,857 Less: Accumulated depreciation (55,250) Less: Unrealized losses on properties held for sale (20,135) Rental property held for sale, net $ 108,848  The following table summarizes the rental property held for sale, net, as of December 31, 2017 (dollars in thousands):     December 31,  2017 Land $ 37,024 Buildings and improvements 273,388 Less: Accumulated depreciation (126,503) Less: Unrealized losses on properties held for sale (12,331) Rental property held for sale,net $ 171,578  

Investments In Unconsolidated_2

Investments In Unconsolidated Joint Ventures (Tables)	12 Months Ended
	Dec. 31, 2018
Investments In Unconsolidated Joint Ventures [Line Items]
Summary Of Unconsolidated Joint Ventures	   Property Debt  Number of Company's Carrying Value As of December 31, 2018  Apartment Units Effective December 31, December 31, Maturity Interest  Entity / Property Name or Rentable Square Feet (sf) Ownership % (a) 2018 2017 Balance Date Rate  Multi-family  Marbella (b) 412 units 24.27 % $ - $ 14,544 $ - - - %  Metropolitan at 40 Park (c) (d) 130 units 25.00 % 7,679 6,834 55,227 (e) (e)  RiverTrace at Port Imperial 316 units 22.50 % 8,112 8,864 82,000 11/10/26 3.21 %  Crystal House (f) 825 units 25.00 % 29,570 30,570 162,838 04/01/20 3.17 %  PI North - Riverwalk C 360 units 40.00 % 27,175 16,844 - 12/06/21 L+2.75 % (g)  Marbella II (i) 311 units 24.27 % 15,414 16,471 74,690 03/30/19 L+2.25 % (h)  Riverpark at Harrison 141 units 45.00 % 1,272 1,604 29,819 08/01/25 3.70 %  Station House 378 units 50.00 % 37,675 40,124 98,504 07/01/33 4.82 %  Urby at Harborside 762 units 85.00 % 85,317 94,429 191,732 08/01/29 5.197 % (j)  PI North -Land (k) 836 potential units 20.00 % 1,678 1,678 - - -  Liberty Landing 850 potential units 50.00 % 337 337 - - -  Hillsborough 206 160,000 sf 50.00 % 1,962 1,962 - - -   Office  Red Bank 92,878 sf 50.00 % 3,127 4,602 14,000 08/01/23 L+2.25 % (l)  12 Vreeland Road 139,750 sf 50.00 % 7,019 6,734 7,904 07/01/23 2.87 %  Offices at Crystal Lake 106,345 sf 31.25 % 3,442 3,369 4,076 11/01/23 4.76 %   Other  Riverwalk Retail 30,745 sf 20.00 % 1,539 1,625 - - -  Hyatt Regency Jersey City 351 rooms 50.00 % 112 440 100,000 10/01/26 3.668 %  Other (m) 1,320 1,595 - - -  Totals: $ 232,750 $ 252,626 $ 820,790    (a) Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.  (b) On August 2, 2018, the Company acquired its equity partner's 50 percent controlling interest in the venture and, as a result, increased its ownership from a 24.27 percent subordinated interest to 74.27 percent controlling interest. See Note 3: Recent Transactions - Consolidation.  (c) 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.  (d) 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 59 -unit, five story multi-family rental development property ("Lofts at 40 Park"). On December 11, 2018, the Company acquired one of its partner’s interest and as a result, increased its ownership from 12.5 percent interest to 25 percent interest in the Metropolitan and Shops at 40 Park and from 25 percent interest to 50 percent interest in the Lofts at 40 Park.  (e) Property debt balance consists of: (i) an amortizable loan, collateralized by the Metropolitan at 40 Park, with a balance of $36.0 million bears interest at 3.25 percent, matures in September 2020 ; (ii) an interest only loan, collateralized by the Shops at 40 Park, with a balance of $6.1 million, bears interest at LIBOR +2.25 percent, matures in September 2019 ; (iii) a loan with a maximum borrowing amount of $13,950 for the Lofts at 40 Park with a balance of $13.1 million, which bears interest at LIBOR plus 250 basis points and matures in February 2020 .  (f) Included in this is the Company's unconsolidated 50 percent interest in a vacant land to accommodate the development of approximately 295 additional units of which 252 are currently approved.  (g) The venture has a construction loan with a maximum borrowing amount of $112,000 .  (h) The construction loan which had a maximum borrowing amount of $75,000 was amended on 3/30/18 and, subject to certain conditions, provided for four 3 -month extension options with a fee of 6.25 basis points for each extension.  (i) On January 31, 2019, the Company, which held a 24.27 percent subordinated interest in the unconsolidated joint venture, Marbella Tower Urban Renewal Associates South LLC, a 311-unit multi-family operating property located in Jersey City, New Jersey, acquired the majority equity partner’s 50 percent interest in the venture for $77.5 million in cash. The cash portion of the acquisition was funded primarily through borrowings under the Company’s unsecured revolving credit facility. Concurrently with the closing, the joint venture repaid in full the property’s $74.7 million mortgage loan and obtained a new loan in the amount of $117 million.  (j) The construction/permanent loan has a maximum borrowing amount of $192 million. The Company owns an 85 percent interest with shared control over major decisions such as, approval of budgets, property financings and leasing guidelines.  (k) The Company also owns a 20 percent residual interest in undeveloped land parcels: parcels 6, I, and J that can accommodate the development of 836 apartment units.  (l) On August 1, 2018, the venture refinanced its mortgage loan with a maximum borrowing amount of $16,500 , bears interest at LIBOR +2.25% , matures on August 1, 2023 and subject to certain conditions, provided for two extension options.  (m) 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	   Year Ended December 31,  Entity / Property Name 2018 2017 2016  Multi-family  Marbella (b) $ 205 $ 334 $ 231  Metropolitan at 40 Park (455) (311) (317)  RiverTrace at Port Imperial 154 196 (1,146)  Crystal House (874) (923) (870)  PI North - Pier Land (126) (219) (62)  PI North - Riverwalk C - (653) (58)  Marbella II 35 93 (202)  Riverpark at Harrison (232) (252) (190)  Station House (2,096) (1,793) (2,440)  Urby at Harborside (975) (c) (6,356) (219)  Liberty Landing (5) (15) (80)  Hillsborough 206 16 (25) (53)  Office  Red Bank (215) 238 448  12 Vreeland Road 285 496 347  Offices at Crystal Lake 73 89 (15)  Other  Roseland/North Retail, L.L.C./ Riverwalk at Port Imperial (86) (81) (52)  South Pier at Harborside / Hyatt Regency Jersey City on the Hudson 3,672 3,277 24,180  Other 497 (176) (714)  Company's equity in earnings (loss) of unconsolidated joint ventures (a) $ (127) $ (6,081) $ 18,788 (a) Amounts are net of amortization of basis differences of $903 , $792 and $436 for the years ended December 31, 2018 , 2017 and 2016 , respectively. (b) On August 2, 2018, the Company acquired one of its equity partner's 50 percent interest and as a result, increased its ownership from 24.27 percent subordinated interest to 74.27 percent controlling interest , and ceased applying the equity method of accounting at such time. (c) Includes $2.6 million of the Company's share of the venture's income from its first annual sale of an economic tax credit certificate from the State of New Jersey to a third party. The venture has an agreement with a third party to sell it the tax credits over the next nine years for $3 million per year for a total of $27 million. The sales are subject to the venture obtaining the tax credits from the State of New Jersey and transferring the credit certificates each year.
Summary Of Financial Position Of Unconsolidated Joint Ventures	   December 31, December 31,  2018 2017  Assets:  Rental property, net $ 903,253 $ 931,419  Other assets 212,205 207,903  Total assets $ 1,115,458 $ 1,139,322  Liabilities and partners'/  members' capital:  Mortgages and loans payable $ 686,797 $ 689,412  Other liabilities 67,072 80,746  Partners'/members' capital 361,589 369,164  Total liabilities and  partners'/members' capital $ 1,115,458 $ 1,139,322 
Summary Of Results Of Operations Of Unconsolidated Joint Ventures	  Year Ended December 31,  2018 2017 2016  Total revenues $ 310,919 $ 358,751 $ 377,711  Operating and other expenses (230,863) (297,492) (262,703)  Depreciation and amortization (40,193) (31,020) (75,512)  Interest expense (34,874) (25,822) (58,390)  Net income (loss) $ 4,989 $ 4,417 $ (18,894) 
Mack-Cali Realty LP [Member]
Investments In Unconsolidated Joint Ventures [Line Items]
Summary Of Unconsolidated Joint Ventures	   Property Debt  Number of Company's Carrying Value As of December 31, 2018  Apartment Units Effective December 31, December 31, Maturity Interest  Entity / Property Name or Rentable Square Feet (sf) Ownership % (a) 2018 2017 Balance Date Rate  Multi-family  Marbella (b) 412 units 24.27 % $ - $ 14,544 $ - - - %  Metropolitan at 40 Park (c) (d) 130 units 25.00 % 7,679 6,834 55,227 (e) (e)  RiverTrace at Port Imperial 316 units 22.50 % 8,112 8,864 82,000 11/10/26 3.21 %  Crystal House (f) 825 units 25.00 % 29,570 30,570 162,838 04/01/20 3.17 %  PI North - Riverwalk C 360 units 40.00 % 27,175 16,844 - 12/06/21 L+2.75 % (g)  Marbella II (i) 311 units 24.27 % 15,414 16,471 74,690 03/30/19 L+2.25 % (h)  Riverpark at Harrison 141 units 45.00 % 1,272 1,604 29,819 08/01/25 3.70 %  Station House 378 units 50.00 % 37,675 40,124 98,504 07/01/33 4.82 %  Urby at Harborside 762 units 85.00 % 85,317 94,429 191,732 08/01/29 5.197 % (j)  PI North -Land (k) 836 potential units 20.00 % 1,678 1,678 - - -  Liberty Landing 850 potential units 50.00 % 337 337 - - -  Hillsborough 206 160,000 sf 50.00 % 1,962 1,962 - - -   Office  Red Bank 92,878 sf 50.00 % 3,127 4,602 14,000 08/01/23 L+2.25 % (l)  12 Vreeland Road 139,750 sf 50.00 % 7,019 6,734 7,904 07/01/23 2.87 %  Offices at Crystal Lake 106,345 sf 31.25 % 3,442 3,369 4,076 11/01/23 4.76 %   Other  Riverwalk Retail 30,745 sf 20.00 % 1,539 1,625 - - -  Hyatt Regency Jersey City 351 rooms 50.00 % 112 440 100,000 10/01/26 3.668 %  Other (m) 1,320 1,595 - - -  Totals: $ 232,750 $ 252,626 $ 820,790    (a) Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.  (b) On August 2, 2018, the Company acquired its equity partner's 50 percent controlling interest in the venture and, as a result, increased its ownership from a 24.27 percent subordinated interest to 74.27 percent controlling interest. See Note 3: Recent Transactions - Consolidation.  (c) 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.  (d) 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 59 -unit, five story multi-family rental development property ("Lofts at 40 Park"). On December 11, 2018, the Company acquired one of its partner’s interest and as a result, increased its ownership from 12.5 percent interest to 25 percent interest in the Metropolitan and Shops at 40 Park and from 25 percent interest to 50 percent interest in the Lofts at 40 Park.  (e) Property debt balance consists of: (i) an amortizable loan, collateralized by the Metropolitan at 40 Park, with a balance of $36.0 million bears interest at 3.25 percent, matures in September 2020 ; (ii) an interest only loan, collateralized by the Shops at 40 Park, with a balance of $6.1 million, bears interest at LIBOR +2.25 percent, matures in September 2019 ; (iii) a loan with a maximum borrowing amount of $13,950 for the Lofts at 40 Park with a balance of $13.1 million, which bears interest at LIBOR plus 250 basis points and matures in February 2020 .  (f) Included in this is the Company's unconsolidated 50 percent interest in a vacant land to accommodate the development of approximately 295 additional units of which 252 are currently approved.  (g) The venture has a construction loan with a maximum borrowing amount of $112,000 .  (h) The construction loan which had a maximum borrowing amount of $75,000 was amended on 3/30/18 and, subject to certain conditions, provided for four 3 -month extension options with a fee of 6.25 basis points for each extension.  (i) On January 31, 2019, the Company, which held a 24.27 percent subordinated interest in the unconsolidated joint venture, Marbella Tower Urban Renewal Associates South LLC, a 311-unit multi-family operating property located in Jersey City, New Jersey, acquired the majority equity partner’s 50 percent interest in the venture for $77.5 million in cash. The cash portion of the acquisition was funded primarily through borrowings under the Company’s unsecured revolving credit facility. Concurrently with the closing, the joint venture repaid in full the property’s $74.7 million mortgage loan and obtained a new loan in the amount of $117 million.  (j) The construction/permanent loan has a maximum borrowing amount of $192 million. The Company owns an 85 percent interest with shared control over major decisions such as, approval of budgets, property financings and leasing guidelines.  (k) The Company also owns a 20 percent residual interest in undeveloped land parcels: parcels 6, I, and J that can accommodate the development of 836 apartment units.  (l) On August 1, 2018, the venture refinanced its mortgage loan with a maximum borrowing amount of $16,500 , bears interest at LIBOR +2.25% , matures on August 1, 2023 and subject to certain conditions, provided for two extension options.  (m) 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	   Year Ended December 31,  Entity / Property Name 2018 2017 2016  Multi-family  Marbella (b) $ 205 $ 334 $ 231  Metropolitan at 40 Park (455) (311) (317)  RiverTrace at Port Imperial 154 196 (1,146)  Crystal House (874) (923) (870)  PI North - Pier Land (126) (219) (62)  PI North - Riverwalk C - (653) (58)  Marbella II 35 93 (202)  Riverpark at Harrison (232) (252) (190)  Station House (2,096) (1,793) (2,440)  Urby at Harborside (975) (c) (6,356) (219)  Liberty Landing (5) (15) (80)  Hillsborough 206 16 (25) (53)  Office  Red Bank (215) 238 448  12 Vreeland Road 285 496 347  Offices at Crystal Lake 73 89 (15)  Other  Roseland/North Retail, L.L.C./ Riverwalk at Port Imperial (86) (81) (52)  South Pier at Harborside / Hyatt Regency Jersey City on the Hudson 3,672 3,277 24,180  Other 497 (176) (714)  Company's equity in earnings (loss) of unconsolidated joint ventures (a) $ (127) $ (6,081) $ 18,788 (a) Amounts are net of amortization of basis differences of $903 , $792 and $436 for the years ended December 31, 2018 , 2017 and 2016 , respectively. (b) On August 2, 2018, the Company acquired one of its equity partner's 50 percent interest and as a result, increased its ownership from 24.27 percent subordinated interest to 74.27 percent controlling interest , and ceased applying the equity method of accounting at such time. (c) Includes $2.6 million of the Company's share of the venture's income from its first annual sale of an economic tax credit certificate from the State of New Jersey to a third party. The venture has an agreement with a third party to sell it the tax credits over the next nine years for $3 million per year for a total of $27 million. The sales are subject to the venture obtaining the tax credits from the State of New Jersey and transferring the credit certificates each year.
Summary Of Financial Position Of Unconsolidated Joint Ventures	   December 31, December 31,  2018 2017  Assets:  Rental property, net $ 903,253 $ 931,419  Other assets 212,205 207,903  Total assets $ 1,115,458 $ 1,139,322  Liabilities and partners'/  members' capital:  Mortgages and loans payable $ 686,797 $ 689,412  Other liabilities 67,072 80,746  Partners'/members' capital 361,589 369,164  Total liabilities and  partners'/members' capital $ 1,115,458 $ 1,139,322 
Summary Of Results Of Operations Of Unconsolidated Joint Ventures	  Year Ended December 31,  2018 2017 2016  Total revenues $ 310,919 $ 358,751 $ 377,711  Operating and other expenses (230,863) (297,492) (262,703)  Depreciation and amortization (40,193) (31,020) (75,512)  Interest expense (34,874) (25,822) (58,390)  Net income (loss) $ 4,989 $ 4,417 $ (18,894) 

Deferred Charges, Goodwill An_2

Deferred Charges, Goodwill And Other Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2018
Deferred Charges, Goodwill And Other Assets [Line Items]
Schedule Of Deferred Charges, Goodwill And Other Assets	   December 31,  (dollars in thousands) 2018 2017  Deferred leasing costs $ 173,822 $ 199,515  Deferred financing costs - unsecured revolving credit facility (a) 5,356 4,945  179,178 204,460  Accumulated amortization (71,326) (98,956)  Deferred charges, net 107,852 105,504  Notes receivable (b) 47,409 50,167  In-place lease values, related intangibles and other assets, net (c) (d) 89,860 102,757  Goodwill (e) 2,945 2,945  Prepaid expenses and other assets, net (f) 107,168 80,947   Total deferred charges, goodwill and other assets, net $ 355,234 $ 342,320  (a) Deferred financing costs related to all other debt liabilities (other than for the unsecured revolving credit facility) are netted against those debt liabilities for all periods presented. See Note 2: Significant Accounting Policies – Deferred Financing Costs. (b) Includes as of December 31, 2018 and 2017, respectively, a mortgage receivable with a balance of $ 45.2 million and $45.7 million (acquired in August 2017) which bears interest at 5.85 percent and matures in July 2019 , with a three -month extension option and an interest-free note receivable with a net present value of $2.2 million and $2.5 million, which matures in April 2023 . The Company believes these balances are fully collectible. (c) In accordance with ASC 805, Business Combinations, the Company recognizes rental revenue of acquired above and below market lease intangibles over the terms of the respective leases. The impact of amortizing the acquired above and below-market lease intangibles increased revenue by approximately $ 5.3 million, $7.9 million and $1.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The following table summarizes, as of December 31, 2018 , the scheduled amortization of the Company’s acquired above and below-market lease intangibles for each of the five succeeding years (dollars in thousands) :     Acquired Above- Acquired Below-  Market Lease Market Lease Total  Year Intangibles Intangibles Amortization  2019 $ (2,559) $ 5,050 $ 2,491  2020 (2,377) 4,305 1,928  2021 (2,245) 4,186 1,941  2022 (2,132) 4,064 1,932  2023 (1,207) 3,279 2,072  (d) The value of acquired in-place lease intangibles are amortized to expense over the remaining initial terms of the respective leases. The impact of the amortization of acquired in-place lease values is included in depreciation and amortization expense and amounted to approximately $17.9 million, $32.2 million and $14.3 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The following table summarizes, as of December 31, 2018 , the scheduled amortization of the Company’s acquired in-place lease values for each of the five succeeding years (dollars in thousands) :    Year  2019 $ 10,494  2020 8,050  2021 6,884  2022 6,059  2023 4,943   (e) All goodwill is attributable to the Company’s Multi-family Real Estate and Services segment. (f) Includes as of December 31, 2018 and 2017, $49.2 million and $26.9 million, respectively, of proceeds from property sales held by a qualified intermediary.
Schedule Of Fair Value Of The Derivative Financial Instruments	   Fair Value  Asset Derivatives designated December 31,  as hedging instruments 2018 2017 Balance sheet location  Interest rate swaps $ 10,175 $ 8,060 Deferred charges, goodwill and other assets 
Schedule Of Cash Flow Hedging, Derivative Financial Instruments On The Income Statement	   Derivatives in Cash Flow Hedging Relationships Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion) Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion, Reclassification for Forecasted Transactions No Longer Probable of Occurring and Amount Excluded from Effectiveness Testing)  Year ended December 31, 2018 2017 2016 2018 2017 2016 2018 2017 2016   Interest rate swaps $ 5,262 $ 2,869 $ (1,183) Interest expense $ 2,944 $ (2,381) $ (3,398) Interest and other investment income (loss) $ (204) $ (37) $ 631 
Acquired Above And Below Market Lease Intangibles [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Summary Of Scheduled Amortization	   Acquired Above- Acquired Below-  Market Lease Market Lease Total  Year Intangibles Intangibles Amortization  2019 $ (2,559) $ 5,050 $ 2,491  2020 (2,377) 4,305 1,928  2021 (2,245) 4,186 1,941  2022 (2,132) 4,064 1,932  2023 (1,207) 3,279 2,072 
In-Place Leases [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Summary Of Scheduled Amortization	   Year  2019 $ 10,494  2020 8,050  2021 6,884  2022 6,059  2023 4,943 
Mack-Cali Realty LP [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Schedule Of Deferred Charges, Goodwill And Other Assets	   December 31,  (dollars in thousands) 2018 2017  Deferred leasing costs $ 173,822 $ 199,515  Deferred financing costs - unsecured revolving credit facility (a) 5,356 4,945  179,178 204,460  Accumulated amortization (71,326) (98,956)  Deferred charges, net 107,852 105,504  Notes receivable (b) 47,409 50,167  In-place lease values, related intangibles and other assets, net (c) (d) 89,860 102,757  Goodwill (e) 2,945 2,945  Prepaid expenses and other assets, net (f) 107,168 80,947   Total deferred charges, goodwill and other assets, net $ 355,234 $ 342,320  (a) Deferred financing costs related to all other debt liabilities (other than for the unsecured revolving credit facility) are netted against those debt liabilities for all periods presented. See Note 2: Significant Accounting Policies – Deferred Financing Costs. (b) Includes as of December 31, 2018 and 2017, respectively, a mortgage receivable with a balance of $ 45.2 million and $45.7 million (acquired in August 2017) which bears interest at 5.85 percent and matures in July 2019 , with a three -month extension option and an interest-free note receivable with a net present value of $2.2 million and $2.5 million, which matures in April 2023 . The Company believes these balances are fully collectible. (c) In accordance with ASC 805, Business Combinations, the Company recognizes rental revenue of acquired above and below market lease intangibles over the terms of the respective leases. The impact of amortizing the acquired above and below-market lease intangibles increased revenue by approximately $ 5.3 million, $7.9 million and $1.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The following table summarizes, as of December 31, 2018 , the scheduled amortization of the Company’s acquired above and below-market lease intangibles for each of the five succeeding years (dollars in thousands) :     Acquired Above- Acquired Below-  Market Lease Market Lease Total  Year Intangibles Intangibles Amortization  2019 $ (2,559) $ 5,050 $ 2,491  2020 (2,377) 4,305 1,928  2021 (2,245) 4,186 1,941  2022 (2,132) 4,064 1,932  2023 (1,207) 3,279 2,072  (d) The value of acquired in-place lease intangibles are amortized to expense over the remaining initial terms of the respective leases. The impact of the amortization of acquired in-place lease values is included in depreciation and amortization expense and amounted to approximately $17.9 million, $32.2 million and $14.3 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The following table summarizes, as of December 31, 2018 , the scheduled amortization of the Company’s acquired in-place lease values for each of the five succeeding years (dollars in thousands) :    Year  2019 $ 10,494  2020 8,050  2021 6,884  2022 6,059  2023 4,943   (e) All goodwill is attributable to the Company’s Multi-family Real Estate and Services segment. (f) Includes as of December 31, 2018 and 2017, $49.2 million and $26.9 million, respectively, of proceeds from property sales held by a qualified intermediary.
Schedule Of Fair Value Of The Derivative Financial Instruments	   Fair Value  Asset Derivatives designated December 31,  as hedging instruments 2018 2017 Balance sheet location  Interest rate swaps $ 10,175 $ 8,060 Deferred charges, goodwill and other assets 
Schedule Of Cash Flow Hedging, Derivative Financial Instruments On The Income Statement	   Derivatives in Cash Flow Hedging Relationships Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion) Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion, Reclassification for Forecasted Transactions No Longer Probable of Occurring and Amount Excluded from Effectiveness Testing)  Year ended December 31, 2018 2017 2016 2018 2017 2016 2018 2017 2016   Interest rate swaps $ 5,262 $ 2,869 $ (1,183) Interest expense $ 2,944 $ (2,381) $ (3,398) Interest and other investment income (loss) $ (204) $ (37) $ 631 
Mack-Cali Realty LP [Member] | Acquired Above And Below Market Lease Intangibles [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Summary Of Scheduled Amortization	   Acquired Above- Acquired Below-  Market Lease Market Lease Total  Year Intangibles Intangibles Amortization  2019 $ (2,559) $ 5,050 $ 2,491  2020 (2,377) 4,305 1,928  2021 (2,245) 4,186 1,941  2022 (2,132) 4,064 1,932  2023 (1,207) 3,279 2,072 
Mack-Cali Realty LP [Member] | In-Place Leases [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Summary Of Scheduled Amortization	   Year  2019 $ 10,494  2020 8,050  2021 6,884  2022 6,059  2023 4,943 

Restricted Cash (Tables)

Restricted Cash (Tables)	12 Months Ended
	Dec. 31, 2018
Restricted Cash [Line Items]
Schedule Of Restricted Cash	   December 31,  2018 2017  Security deposits $ 10,257 $ 9,446  Escrow and other reserve funds 9,664 30,346   Total restricted cash $ 19,921 $ 39,792 
Mack-Cali Realty LP [Member]
Restricted Cash [Line Items]
Schedule Of Restricted Cash	   December 31,  2018 2017  Security deposits $ 10,257 $ 9,446  Escrow and other reserve funds 9,664 30,346   Total restricted cash $ 19,921 $ 39,792 

Senior Unsecured Notes (Tables)

Senior Unsecured Notes (Tables) - Unsecured Note [Member]	12 Months Ended
	Dec. 31, 2018
Debt Instrument [Line Items]
Summary Of Senior Unsecured Notes	    December 31, December 31, Effective  2018 2017 Rate (1)  4.500% Senior Unsecured Notes, due April 18, 2022 $ 300,000 $ 300,000 4.612 %  3.150% Senior Unsecured Notes, due May 15, 2023 275,000 275,000 3.517  Principal balance outstanding 575,000 575,000  Adjustment for unamortized debt discount (2,838) (3,505)  Unamortized deferred financing costs (1,848) (2,350)   Total senior unsecured notes, net $ 570,314 $ 569,145  (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. 
Mack-Cali Realty LP [Member]
Debt Instrument [Line Items]
Summary Of Senior Unsecured Notes	    December 31, December 31, Effective  2018 2017 Rate (1)  4.500% Senior Unsecured Notes, due April 18, 2022 $ 300,000 $ 300,000 4.612 %  3.150% Senior Unsecured Notes, due May 15, 2023 275,000 275,000 3.517  Principal balance outstanding 575,000 575,000  Adjustment for unamortized debt discount (2,838) (3,505)  Unamortized deferred financing costs (1,848) (2,350)   Total senior unsecured notes, net $ 570,314 $ 569,145  (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 Fa_2

Unsecured Revolving Credit Facility And Term Loans (Tables)	12 Months Ended
	Dec. 31, 2018
Unsecured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Schedule Of Unsecured Credit Rating And Facility Fee	   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 (since January 2017 amendment) 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 
2017 Credit Facility [Member]
Debt Instrument [Line Items]
Schedule Of Defined Leverage Ratio, Including Interest Rate, Alternate Base Rate Loans, And Facility Fee	   Interest Rate -  Applicable Basis Points  Interest Rate - Above LIBOR for  Applicable Basis Alternate Base Rate Facility Fee  Total Leverage Ratio Points above LIBOR Loans Basis Points  < 45% 125.0 25.0 20.0  ≥ 45% and <50% (current ratio) 130.0 30.0 25.0  ≥ 50% and <55% 135.0 35.0 30.0  ≥ 55% 160.0 60.0 35.0 
Schedule Of Interest Rates On Outstanding Borrowings, Alternate Base Rate Loans, And Facility Fee	   Interest Rate -  Applicable Basis Points  Operating Partnership's Interest Rate - Above LIBOR for  Unsecured Debt Ratings: Applicable Basis Points Alternate Base Rate Facility Fee  Higher of S&P or Moody's Above LIBOR Loans Basis Points  No ratings or less than BBB-/Baa3 155.0 55.0 30.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 120.0 20.0 25.0  BBB or Baa2 100.0 0.0 20.0  BBB+ or Baa1 90.0 0.0 15.0  A- or A3 or higher 87.5 0.0 12.5 
Mack-Cali Realty LP [Member] | Unsecured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Schedule Of Unsecured Credit Rating And Facility Fee	   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 (since January 2017 amendment) 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 
Mack-Cali Realty LP [Member] | 2017 Credit Facility [Member]
Debt Instrument [Line Items]
Schedule Of Defined Leverage Ratio, Including Interest Rate, Alternate Base Rate Loans, And Facility Fee	   Interest Rate -  Applicable Basis Points  Interest Rate - Above LIBOR for  Applicable Basis Alternate Base Rate Facility Fee  Total Leverage Ratio Points above LIBOR Loans Basis Points  < 45% 125.0 25.0 20.0  ≥ 45% and <50% (current ratio) 130.0 30.0 25.0  ≥ 50% and <55% 135.0 35.0 30.0  ≥ 55% 160.0 60.0 35.0 
Schedule Of Interest Rates On Outstanding Borrowings, Alternate Base Rate Loans, And Facility Fee	   Interest Rate -  Applicable Basis Points  Operating Partnership's Interest Rate - Above LIBOR for  Unsecured Debt Ratings: Applicable Basis Points Alternate Base Rate Facility Fee  Higher of S&P or Moody's Above LIBOR Loans Basis Points  No ratings or less than BBB-/Baa3 155.0 55.0 30.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 120.0 20.0 25.0  BBB or Baa2 100.0 0.0 20.0  BBB+ or Baa1 90.0 0.0 15.0  A- or A3 or higher 87.5 0.0 12.5 
2017 Term Loan [Member]
Debt Instrument [Line Items]
Schedule Of Defined Leverage Ratio	   Interest Rate -  Applicable Basis Points  Interest Rate - Above LIBOR for  Applicable Basis Alternate Base Rate  Total Leverage Ratio Points above LIBOR Loans  < 45% 145.0 45.0  ≥ 45% and < 50% (current ratio) 155.0 55.0  ≥ 50% and < 55% 165.0 65.0  ≥ 55% 195.0 95.0 
Schedule Of Interest Rate On Outstanding Borrowings Payable	   Interest Rate -  Applicable Basis Points  Operating Partnership's Interest Rate - Above LIBOR for  Unsecured Debt Ratings: Applicable Basis Points Alternate Base Rate  Higher of S&P or Moody's Above LIBOR Loans  No ratings or less than BBB-/Baa3 185.0 85.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 140.0 40.0  BBB or Baa2 115.0 15.0  BBB+ or Baa1 100.0 0.0  A- or A3 or higher 90.0 0.0 
2017 Term Loan [Member] | Mack-Cali Realty LP [Member]
Debt Instrument [Line Items]
Schedule Of Defined Leverage Ratio	   Interest Rate -  Applicable Basis Points  Interest Rate - Above LIBOR for  Applicable Basis Alternate Base Rate  Total Leverage Ratio Points above LIBOR Loans  < 45% 145.0 45.0  ≥ 45% and < 50% (current ratio) 155.0 55.0  ≥ 50% and < 55% 165.0 65.0  ≥ 55% 195.0 95.0 
Schedule Of Interest Rate On Outstanding Borrowings Payable	   Interest Rate -  Applicable Basis Points  Operating Partnership's Interest Rate - Above LIBOR for  Unsecured Debt Ratings: Applicable Basis Points Alternate Base Rate  Higher of S&P or Moody's Above LIBOR Loans  No ratings or less than BBB-/Baa3 185.0 85.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 140.0 40.0  BBB or Baa2 115.0 15.0  BBB+ or Baa1 100.0 0.0  A- or A3 or higher 90.0 0.0 
2016 Term Loan [Member]
Debt Instrument [Line Items]
Schedule Of Defined Leverage Ratio	   Interest Rate -  Applicable Basis  Total Leverage Ratio Points above LIBOR  < 45% 145.0  ≥ 45% and < 50% (current ratio) 155.0  ≥ 50% and < 55% 165.0  ≥ 55% 195.0 
Schedule Of Interest Rate On Outstanding Borrowings Payable	   Operating Partnership's Interest Rate -  Unsecured Debt Ratings: Applicable Basis Points  Higher of S&P or Moody's Above LIBOR  No ratings or less than BBB-/Baa3 185.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 140.0  BBB or Baa2 115.0  BBB+ or Baa1 100.0  A- or A3 or higher 90.0 
2016 Term Loan [Member] | Mack-Cali Realty LP [Member]
Debt Instrument [Line Items]
Schedule Of Defined Leverage Ratio	   Interest Rate -  Applicable Basis  Total Leverage Ratio Points above LIBOR  < 45% 145.0  ≥ 45% and < 50% (current ratio) 155.0  ≥ 50% and < 55% 165.0  ≥ 55% 195.0 
Schedule Of Interest Rate On Outstanding Borrowings Payable	   Operating Partnership's Interest Rate -  Unsecured Debt Ratings: Applicable Basis Points  Higher of S&P or Moody's Above LIBOR  No ratings or less than BBB-/Baa3 185.0  BBB- or Baa3 (interest rate based on Company's election through March 5, 2018) 140.0  BBB or Baa2 115.0  BBB+ or Baa1 100.0  A- or A3 or higher 90.0 

Mortgages, Loans Payable And _2

Mortgages, Loans Payable And Other Obligations (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Instrument [Line Items]
Summary Of Mortgages, Loans Payable And Other Obligations	   Effective December 31, December 31,  Property/Project Name Lender Rate (a) 2018 2017 Maturity  Harborside Plaza 5 (b) The Northwestern Mutual Life Insurance Co. 6.84 % $ - $ 209,257  & New York Life Insurance Co.  23 Main Street (c) Berkadia CMBS 5.59 % - 27,090  One River Center (d) Guardian Life Insurance Co. 7.31 % - 40,485  Park Square (e) Wells Fargo Bank N.A. LIBOR+1.87 % 25,167 26,567 04/10/19  250 Johnson (f) M&T Bank LIBOR+2.35 % 41,769 32,491 05/20/19  Port Imperial 4/5 Hotel (g) Fifth Third Bank & Santander LIBOR+4.50 % 73,350 43,674 10/06/19  Worcester (h) Citizens Bank LIBOR+2.50 % 56,892 37,821 12/10/19  Monaco (i) The Northwestern Mutual Life Insurance Co. 3.15 % 168,370 169,987 02/01/21  Port Imperial South 4/5 Retail American General Life & A/G PC 4.56 % 4,000 4,000 12/01/21  Portside 7 CBRE Capital Markets/FreddieMac 3.57 % 58,998 58,998 08/01/23  Alterra I & II Capital One/FreddieMac 3.85 % 100,000 100,000 02/01/24  The Chase at Overlook Ridge New York Community Bank 3.74 % 135,750 135,750 01/01/25  Portside 5/6 (j) New York Life Insurance Company 4.56 % 97,000 45,778 03/10/26  Marbella New York Life Insurance Company 4.17 % 131,000 - 08/10/26  101 Hudson Wells Fargo CMBS 3.20 % 250,000 250,000 10/11/26  Short Hills Portfolio (k) Wells Fargo CMBS 4.15 % 124,500 124,500 04/01/27  150 Main St. Natixis Real Estate Capital LLC 4.48 % 41,000 41,000 08/05/27  Port Imperial South 11 (l) The Northwestern Mutual Life Insurance Co. 4.52 % 100,000 46,113 01/10/29  Port Imperial South 4/5 Garage American General Life & A/G PC 4.85 % 32,600 32,600 12/01/29   Principal balance outstanding 1,440,396 1,426,111  Unamortized deferred financing costs (8,998) (7,976)   Total mortgages, loans payable and other obligations, net $ 1,431,398 $ 1,418,135      (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 January 8, 2018 , the Company prepaid this loan in full upon payment of a fee of approximately $8.4 million using borrowings from the Company's unsecured revolving credit facility.  (c) On March 1, 2018, the Company prepaid this loan in full upon payment of a fee of approximately $0.1 million using borrowings from the Company's unsecured revolving credit facility.  (d) Mortgage was collateralized by the three properties comprising One River Center. On March 29, 2018 , the Company prepaid this loan in full upon payment of a fee of approximately $1.8 million using borrowings from the Company's unsecured revolving credit facility.  (e) On January 16, 2019, the loan was repaid using proceeds from the disposition of Park Square.  (f) This construction loan has a maximum borrowing capacity of $42 million and provides, subject to certain conditions, a one -year extension option with a fee of 25 basis points.  (g) This construction loan has a maximum borrowing capacity of $94 million and provides, subject to certain conditions, two one -year extension options with a fee of 20 basis points for each year. See Note 12: Commitments and Contingencies - Construction Projects.  (h) This construction loan has a maximum borrowing capacity of $58 million and provides, subject to certain conditions, two one -year extension options with a fee of 15 basis points each year.  (i) This mortgage loan, which includes unamortized fair value adjustment of $3.4 million as of December 31, 2018, was assumed by the Company in April 2017 with the acquisition and consolidation of all the interests in the Monaco Towers property.  (j) On December 7, 2018 , the Company refinanced this loan, due to which unamortized deferred financing costs of $0.2 million pertaining to the initial loan were written off. Concurrent with the refinancing, the Company repaid in full the property's $70 million construction loan and obtained a new loan in the amount of $97 million.  (k) This mortgage loan was obtained by the Company in March 2017 to partially fund the acquisition of the Short Hills/Madison portfolio.  (l) On December 17, 2018, the Company refinanced this loan, due to which unamortized deferred financing costs of $0.3 million pertaining to the initial loan were written off. Concurrent with the refinancing, the Company repaid in full the property's $70.1 million construction loan and obtained a new loan in the amount of $100 million. 
Schedule Of Principal Payments	   Scheduled Principal  Period Amortization Maturities Total  2019 (a) $ 532 $ 546,711 $ 547,243  2020 2,903 325,000 327,903  2021 3,227 285,800 289,027  2022 3,284 300,000 303,284  2023 3,412 333,998 337,410  Thereafter 7,230 991,929 999,159  Sub-total 20,588 2,783,438 2,804,026  Adjustment for unamortized debt  discount/premium, net  December 31, 2018 (2,838) - (2,838)  Unamortized mark to market 3,370 - 3,370  Unamortized deferred financing costs (11,907) (11,907)   Totals/Weighted Average $ 9,213 $ 2,783,438 $ 2,792,651  (a) On January 7, 2019, the Company exercised the first one -year extension option on the $350 million term loan scheduled to mature in January 2019 , which extended the maturity of the 2016 Term Loan to January 2020 . 
Mack-Cali Realty LP [Member]
Debt Instrument [Line Items]
Summary Of Mortgages, Loans Payable And Other Obligations	   Effective December 31, December 31,  Property/Project Name Lender Rate (a) 2018 2017 Maturity  Harborside Plaza 5 (b) The Northwestern Mutual Life Insurance Co. 6.84 % $ - $ 209,257  & New York Life Insurance Co.  23 Main Street (c) Berkadia CMBS 5.59 % - 27,090  One River Center (d) Guardian Life Insurance Co. 7.31 % - 40,485  Park Square (e) Wells Fargo Bank N.A. LIBOR+1.87 % 25,167 26,567 04/10/19  250 Johnson (f) M&T Bank LIBOR+2.35 % 41,769 32,491 05/20/19  Port Imperial 4/5 Hotel (g) Fifth Third Bank & Santander LIBOR+4.50 % 73,350 43,674 10/06/19  Worcester (h) Citizens Bank LIBOR+2.50 % 56,892 37,821 12/10/19  Monaco (i) The Northwestern Mutual Life Insurance Co. 3.15 % 168,370 169,987 02/01/21  Port Imperial South 4/5 Retail American General Life & A/G PC 4.56 % 4,000 4,000 12/01/21  Portside 7 CBRE Capital Markets/FreddieMac 3.57 % 58,998 58,998 08/01/23  Alterra I & II Capital One/FreddieMac 3.85 % 100,000 100,000 02/01/24  The Chase at Overlook Ridge New York Community Bank 3.74 % 135,750 135,750 01/01/25  Portside 5/6 (j) New York Life Insurance Company 4.56 % 97,000 45,778 03/10/26  Marbella New York Life Insurance Company 4.17 % 131,000 - 08/10/26  101 Hudson Wells Fargo CMBS 3.20 % 250,000 250,000 10/11/26  Short Hills Portfolio (k) Wells Fargo CMBS 4.15 % 124,500 124,500 04/01/27  150 Main St. Natixis Real Estate Capital LLC 4.48 % 41,000 41,000 08/05/27  Port Imperial South 11 (l) The Northwestern Mutual Life Insurance Co. 4.52 % 100,000 46,113 01/10/29  Port Imperial South 4/5 Garage American General Life & A/G PC 4.85 % 32,600 32,600 12/01/29   Principal balance outstanding 1,440,396 1,426,111  Unamortized deferred financing costs (8,998) (7,976)   Total mortgages, loans payable and other obligations, net $ 1,431,398 $ 1,418,135      (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 January 8, 2018 , the Company prepaid this loan in full upon payment of a fee of approximately $8.4 million using borrowings from the Company's unsecured revolving credit facility.  (c) On March 1, 2018, the Company prepaid this loan in full upon payment of a fee of approximately $0.1 million using borrowings from the Company's unsecured revolving credit facility.  (d) Mortgage was collateralized by the three properties comprising One River Center. On March 29, 2018 , the Company prepaid this loan in full upon payment of a fee of approximately $1.8 million using borrowings from the Company's unsecured revolving credit facility.  (e) On January 16, 2019, the loan was repaid using proceeds from the disposition of Park Square.  (f) This construction loan has a maximum borrowing capacity of $42 million and provides, subject to certain conditions, a one -year extension option with a fee of 25 basis points.  (g) This construction loan has a maximum borrowing capacity of $94 million and provides, subject to certain conditions, two one -year extension options with a fee of 20 basis points for each year. See Note 12: Commitments and Contingencies - Construction Projects.  (h) This construction loan has a maximum borrowing capacity of $58 million and provides, subject to certain conditions, two one -year extension options with a fee of 15 basis points each year.  (i) This mortgage loan, which includes unamortized fair value adjustment of $3.4 million as of December 31, 2018, was assumed by the Company in April 2017 with the acquisition and consolidation of all the interests in the Monaco Towers property.  (j) On December 7, 2018 , the Company refinanced this loan, due to which unamortized deferred financing costs of $0.2 million pertaining to the initial loan were written off. Concurrent with the refinancing, the Company repaid in full the property's $70 million construction loan and obtained a new loan in the amount of $97 million.  (k) This mortgage loan was obtained by the Company in March 2017 to partially fund the acquisition of the Short Hills/Madison portfolio.  (l) On December 17, 2018, the Company refinanced this loan, due to which unamortized deferred financing costs of $0.3 million pertaining to the initial loan were written off. Concurrent with the refinancing, the Company repaid in full the property's $70.1 million construction loan and obtained a new loan in the amount of $100 million. 
Schedule Of Principal Payments	   Scheduled Principal  Period Amortization Maturities Total  2019 (a) $ 532 $ 546,711 $ 547,243  2020 2,903 325,000 327,903  2021 3,227 285,800 289,027  2022 3,284 300,000 303,284  2023 3,412 333,998 337,410  Thereafter 7,230 991,929 999,159  Sub-total 20,588 2,783,438 2,804,026  Adjustment for unamortized debt  discount/premium, net  December 31, 2018 (2,838) - (2,838)  Unamortized mark to market 3,370 - 3,370  Unamortized deferred financing costs (11,907) (11,907)   Totals/Weighted Average $ 9,213 $ 2,783,438 $ 2,792,651  (a) On January 7, 2019, the Company exercised the first one -year extension option on the $350 million term loan scheduled to mature in January 2019 , which extended the maturity of the 2016 Term Loan to January 2020 . 

Commitments And Contingencies (

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies Disclosure [Line Items]
Future Minimum Rental Payments Of Ground Leases	   Year Amount  2019 $ 2,470  2020 2,491  2021 2,491  2022 2,491  2023 2,491  2024 through 2084 210,117   Total $ 222,551 
Mack-Cali Realty LP [Member]
Commitments And Contingencies Disclosure [Line Items]
Future Minimum Rental Payments Of Ground Leases	   Year Amount  2019 $ 2,470  2020 2,491  2021 2,491  2022 2,491  2023 2,491  2024 through 2084 210,117   Total $ 222,551 

Tenant Leases (Tables)

Tenant Leases (Tables)	12 Months Ended
	Dec. 31, 2018
Leases [Line Items]
Future Minimum Rentals To Be Received Under Non-Cancelable Operating Leases	   Year Amount  2019 $ 314,708  2020 306,559  2021 284,120  2022 258,076  2023 220,533  2024 and thereafter 923,061   Total $ 2,307,057 
Mack-Cali Realty LP [Member]
Leases [Line Items]
Future Minimum Rentals To Be Received Under Non-Cancelable Operating Leases	   Year Amount  2019 $ 314,708  2020 306,559  2021 284,120  2022 258,076  2023 220,533  2024 and thereafter 923,061   Total $ 2,307,057 

Redeemable Noncontrolling Int_2

Redeemable Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2018
Redeemable Noncontrolling Interest [Line Items]
Schedule Of Changes In The Value Of The Redeemable Noncontrolling Interests	   Series A and Total  A-1 Preferred Rockpoint Redeemable  Units Interests Noncontrolling  In MCRLP in RRT Interests  Balance January 1, 2018 $ 52,324 $ 159,884 $ 212,208  Redeemable Noncontrolling Interests Issued - 105,000 105,000  Net 52,324 264,884 317,208  Income Attributed to Noncontrolling Interests 1,820 12,159 13,979  Distributions (1,820) (12,159) (13,979)  Redemption Value Adjustment - 13,251 13,251  Redeemable noncontrolling interests as of December 31, 2018 $ 52,324 $ 278,135 $ 330,459 
Mack-Cali Realty LP [Member]
Redeemable Noncontrolling Interest [Line Items]
Schedule Of Changes In The Value Of The Redeemable Noncontrolling Interests	   Series A and Total  A-1 Preferred Rockpoint Redeemable  Units Interests Noncontrolling  In MCRLP in RRT Interests  Balance January 1, 2018 $ 52,324 $ 159,884 $ 212,208  Redeemable Noncontrolling Interests Issued - 105,000 105,000  Net 52,324 264,884 317,208  Income Attributed to Noncontrolling Interests 1,820 12,159 13,979  Distributions (1,820) (12,159) (13,979)  Redemption Value Adjustment - 13,251 13,251  Redeemable noncontrolling interests as of December 31, 2018 $ 52,324 $ 278,135 $ 330,459 

Mack-Cali Realty Corporation _2

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Tables)	12 Months Ended
	Dec. 31, 2018
Stockolders Equity [Line Items]
Schedule Of Stock Option Plans	   Weighted Aggregate  Average Intrinsic  Shares Exercise Value  Under Options Price $(000’s)  Outstanding at January 1, 2016 805,000 $ 17.33 $ 4,843  Lapsed or Cancelled (5,000) 21.25 -  Outstanding at December 31, 2016 ( $17.31 ) 800,000 $ 17.31 9,368  Granted, Lapsed or Cancelled - -  Outstanding at December 31, 2017 ($17.31) 800,000 $ 17.31 3,400  Granted, Lapsed or Cancelled - -  Outstanding at December 31, 2018 ($17.31) 800,000 $ 17.31 $ 1,824  Options exercisable at December 31, 2018 800,000  Available for grant at December 31, 2018 1,580,869 
Schedule Of Restricted Stock Awards	   Weighted-Average  Grant – Date  Shares Fair Value  Outstanding at January 1, 2016 136,220 $ 19.36  Granted 74,622 23.79  Vested (61,654) 18.94  Forfeited (3,910) 21.58  Outstanding at December 31, 2016 145,278 $ 21.76  Granted 59,985 27.00  Vested (95,009) 20.73  Forfeited (1,936) 25.83  Outstanding at December 31, 2017 108,318 $ 25.49  Granted 40,185 20.16  Vested (72,502) 25.33  Forfeited (8,712) 25.83  Outstanding at December 31, 2018 67,289 $ 22.43 
Schedule Of Reconciliation Of Shares Used In Basic EPS Calculation To Shares Used In Diluted EPS Calculation	   Year Ended December 31,  Computation of Basic EPS 2018 2017 2016  Net income $ 106,401 $ 33,718 $ 130,294  Add: Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Add (deduct): Noncontrolling interest in Operating Partnership (9,527) (2,711) (13,721)  Deduct: Redeemable noncontrolling interest (13,979) (8,840) -  Deduct: Redemption value adjustment of redeemable noncontrolling  interests attributable to common shareholders (11,425) (17,951) -  Net income available to common shareholders for basic earnings per share $ 72,686 $ 5,234 $ 117,224   Weighted average common shares 90,388 90,005 89,746   Basic EPS :  Net income available to common shareholders $ 0.80 $ 0.06 $ 1.31         Year Ended December 31,  Computation of Diluted EPS 2018 2017 2016  Net income available to common shareholders for basic earnings per share $ 72,686 $ 5,234 $ 117,224  Add (deduct): Noncontrolling interest in Operating Partnership 9,527 2,711 13,721  Deduct: Redemption value adjustment of redeemable noncontrolling  interests attributable to the Operating Partnership unitholders (1,296) (2,074) -  Net income available for diluted earnings per share $ 80,917 $ 5,871 $ 130,945   Weighted average common shares 100,724 100,703 100,498   Diluted EPS :  Net income available to common shareholders $ 0.80 $ 0.06 $ 1.30   The following schedule reconciles the weighted average shares used in the basic EPS calculation to the shares used in the diluted EPS calculation (in thousands):   Year Ended December 31,  2018 2017 2016  Basic EPS shares 90,388 90,005 89,746  Add: Operating Partnership – common and vested LTIP units 10,246 10,405 10,499  Restricted Stock Awards - 40 43  Stock Options 90 253 210  Diluted EPS Shares 100,724 100,703 100,498 
Mack-Cali Realty LP [Member]
Stockolders Equity [Line Items]
Schedule Of Stock Option Plans	   Weighted Aggregate  Average Intrinsic  Shares Exercise Value  Under Options Price $(000’s)  Outstanding at January 1, 2016 805,000 $ 17.33 $ 4,843  Lapsed or Cancelled (5,000) 21.25 -  Outstanding at December 31, 2016 ( $17.31 ) 800,000 $ 17.31 9,368  Granted, Lapsed or Cancelled - -  Outstanding at December 31, 2017 ($17.31) 800,000 $ 17.31 3,400  Granted, Lapsed or Cancelled - -  Outstanding at December 31, 2018 ($17.31) 800,000 $ 17.31 $ 1,824  Options exercisable at December 31, 2018 800,000  Available for grant at December 31, 2018 1,580,869 
Schedule Of Restricted Stock Awards	   Weighted-Average  Grant – Date  Shares Fair Value  Outstanding at January 1, 2016 136,220 $ 19.36  Granted 74,622 23.79  Vested (61,654) 18.94  Forfeited (3,910) 21.58  Outstanding at December 31, 2016 145,278 $ 21.76  Granted 59,985 27.00  Vested (95,009) 20.73  Forfeited (1,936) 25.83  Outstanding at December 31, 2017 108,318 $ 25.49  Granted 40,185 20.16  Vested (72,502) 25.33  Forfeited (8,712) 25.83  Outstanding at December 31, 2018 67,289 $ 22.43 
Schedule Of Reconciliation Of Shares Used In Basic EPS Calculation To Shares Used In Diluted EPS Calculation	   Year Ended December 31,  Computation of Basic EPU 2018 2017 2016  Net income $ 106,401 $ 33,718 $ 130,294  Add: Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Deduct: Redeemable noncontrolling interest (13,979) (8,840) -  Deduct: Redemption value adjustment of redeemable noncontrolling interests (12,721) (20,025) -  Net income available to common unitholders for basic earnings per unit $ 80,917 $ 5,871 $ 130,945   Weighted average common units 100,634 100,410 100,245   Basic EPU :  Net income available to common unitholders for basic earnings per unit $ 0.80 $ 0.06 $ 1.31    Year Ended December 31,  Computation of Diluted EPU 2018 2017 2016  Net income available to common unitholders for diluted earnings per unit $ 80,917 $ 5,871 $ 130,945   Weighted average common unit 100,724 100,703 100,498   Diluted EPU :  Net income available to common unitholders $ 0.80 $ 0.06 $ 1.30  The following schedule reconciles the weighted average units used in the basic EPU calculation to the units used in the diluted EPU calculation (in thousands) :    Year Ended December 31,  2018 2017 2016  Basic EPU units 100,634 100,410 100,245  Add: Restricted Stock Awards - 40 43  Stock Options 90 253 210  Diluted EPU Units 100,724 100,703 100,498 

Noncontrolling Interests In S_2

Noncontrolling Interests In Subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2018
Noncontrolling Interests In Subsidiaries [Abstract]
Changes In Noncontrolling Interests Of Subsidiaries	   Common LTIP  Units Units  Balance at January 1, 2016 10,516,844 -  Redemption of common units for shares of common stock (28,739) -  Issuance of units - 657,373  Balance at December 31, 2016 10,488,105 657,373  Redemption of common units for shares of common stock (148,662) -  Issuance of units 99,412 578,323  Cancellation of units - (4,819)  Balance at December 31, 2017 10,438,855 1,230,877  Redemption of common units for shares of common stock (264,570) -  Issuance of units - 864,024  Cancellation of units - (332,731)   Balance at December 31, 2018 10,174,285 1,762,170 

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting Information [Line Items]
Schedule Of Selected Results Of Operations And Asset Information	  Commercial Multi-family Corporate Total  & Other Real Estate Real Estate & Services (d) & Other (e) Company  Total revenues:  2018 $ 416,369 $ 113,805 $ 432 $ 530,606  2017 522,223 90,654 3,323 616,200  2016 541,271 69,873 2,254 613,398   Total operating and  interest expenses (a):  2018 $ 183,439 $ 70,280 $ 104,788 $ 358,507  2017 238,055 63,589 94,662 396,306  2016 263,663 60,646 91,042 415,351   Equity in earnings (loss) of  unconsolidated joint ventures:  2018 $ 2,319 $ (2,446) $ - $ (127)  2017 1,644 (7,725) - (6,081)  2016 23,796 (5,008) - 18,788  -  Net operating income (loss) (b):  2018 $ 235,249 $ 41,079 $ (104,356) $ 171,972  2017 285,812 19,340 (91,339) 213,813  2016 301,404 4,219 (88,788) 216,835   Total assets:  2018 $ 2,687,178 $ 2,260,497 $ 112,969 $ 5,060,644  2017 2,915,646 1,937,708 104,531 4,957,885   Total long-lived assets (c):  2018 $ 2,413,696 $ 1,973,826 $ 33,157 $ 4,420,679  2017 2,613,815 1,645,410 31,901 4,291,126   Total investments in  unconsolidated joint ventures:  2018 $ 13,699 $ 218,771 $ 280 $ 232,750  2017 15,143 237,321 162 252,626   (a) Total operating and interest expenses represent the sum of: real estate taxes; utilities; operating services; real estate services expenses; general and administrative, acquisition-related costs 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 and classified 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) Segment assets and operations were owned through a consolidated variable interest entity commencing in February 2018 . (e) Corporate & Other represents all corporate-level items (including interest and other investment income, interest expense, non-property general and administrative expense) as well as intercompany eliminations necessary to reconcile to consolidated Company totals.
Schedule Of Reconciliation Of Net Operating Income To Net Income Available To Common Shareholders	   Year Ended December 31,  2018 2017 2016  Net operating income $ 171,972 $ 213,813 $ 216,835  Add (deduct):  Depreciation and amortization (174,847) (205,169) (186,684)  Land Impairments (24,566) - -  Gain on change of control of interests 14,217 - 15,347  Realized gains (losses) and unrealized losses on disposition of  rental property, net 99,436 2,364 109,666  Gain on disposition of developable land 30,939 - -  Gain on sale of investment in unconsolidated joint venture - 23,131 5,670  Loss from extinguishment of debt, net (10,750) (421) (30,540)  Net income 106,401 33,718 130,294  Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Noncontrolling interest in Operating Partnership (9,527) (2,711) (13,721)  Redeemable noncontrolling interest (13,979) (8,840) -  Net income available to common shareholders $ 84,111 $ 23,185 $ 117,224 
Mack-Cali Realty LP [Member]
Segment Reporting Information [Line Items]
Schedule Of Selected Results Of Operations And Asset Information	  Commercial Multi-family Corporate Total  & Other Real Estate Real Estate & Services (d) & Other (e) Company  Total revenues:  2018 $ 416,369 $ 113,805 $ 432 $ 530,606  2017 522,223 90,654 3,323 616,200  2016 541,271 69,873 2,254 613,398   Total operating and  interest expenses (a):  2018 $ 183,439 $ 70,280 $ 104,788 $ 358,507  2017 238,055 63,589 94,662 396,306  2016 263,663 60,646 91,042 415,351   Equity in earnings (loss) of  unconsolidated joint ventures:  2018 $ 2,319 $ (2,446) $ - $ (127)  2017 1,644 (7,725) - (6,081)  2016 23,796 (5,008) - 18,788  -  Net operating income (loss) (b):  2018 $ 235,249 $ 41,079 $ (104,356) $ 171,972  2017 285,812 19,340 (91,339) 213,813  2016 301,404 4,219 (88,788) 216,835   Total assets:  2018 $ 2,687,178 $ 2,260,497 $ 112,969 $ 5,060,644  2017 2,915,646 1,937,708 104,531 4,957,885   Total long-lived assets (c):  2018 $ 2,413,696 $ 1,973,826 $ 33,157 $ 4,420,679  2017 2,613,815 1,645,410 31,901 4,291,126   Total investments in  unconsolidated joint ventures:  2018 $ 13,699 $ 218,771 $ 280 $ 232,750  2017 15,143 237,321 162 252,626   (a) Total operating and interest expenses represent the sum of: real estate taxes; utilities; operating services; real estate services expenses; general and administrative, acquisition-related costs 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 and classified 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) Segment assets and operations were owned through a consolidated variable interest entity commencing in February 2018 . (e) Corporate & Other represents all corporate-level items (including interest and other investment income, interest expense, non-property general and administrative expense) as well as intercompany eliminations necessary to reconcile to consolidated Company totals.
Schedule Of Reconciliation Of Net Operating Income To Net Income Available To Common Shareholders	   Year Ended December 31,  2018 2017 2016  Net operating income $ 171,972 $ 213,813 $ 216,835  Add (deduct):  Depreciation and amortization (174,847) (205,169) (186,684)  Land Impairments (24,566) - -  Gain on change of control of interests 14,217 - 15,347  Realized gains (losses) and unrealized losses on disposition of  rental property, net 99,436 2,364 109,666  Gain on disposition of developable land 30,939 - -  Gain on sale of investment in unconsolidated joint venture - 23,131 5,670  Loss from extinguishment of debt, net (10,750) (421) (30,540)  Net income 106,401 33,718 130,294  Noncontrolling interest in consolidated joint ventures 1,216 1,018 651  Redeemable noncontrolling interest (13,979) (8,840)  Net income available to common unitholders $ 93,638 $ 25,896 $ 130,945 

Condensed Quarterly Financial_2

Condensed Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2018
Summary Of Condensed Quarterly Financial Information	  Quarter Ended 2018 December 31 September 30 June 30 March 31  Total revenues $ 132,936 $ 132,114 $ 126,589 $ 138,967  Net income $ 52,523 $ 1,689 $ 1,501 $ 50,688  Net income (loss) available to common shareholders $ 43,804 $ (1,478) $ (1,251) $ 43,036  `  Basic earnings per common share:  Net income (loss) available to common shareholders $ 0.45 $ (0.05) $ (0.05) $ 0.45   Diluted earnings per common share:  Net income (loss) available to common shareholders $ 0.45 $ (0.05) $ (0.05) $ 0.45       Quarter Ended 2017 December 31 September 30 June 30 March 31  Total revenues $ 143,529 $ 160,018 $ 162,766 $ 149,887  Net income (loss) $ 5,411 $ 44,703 $ (39,125) $ 22,729  Net income (loss) available to common shareholders $ 2,582 $ 38,054 $ (37,330) $ 19,879   Basic earnings per common share:  Net income (loss) available to common shareholders $ (0.01) $ 0.39 $ (0.44) $ 0.11   Diluted earnings per common share:  Net income (loss) available to common shareholders $ (0.01) $ 0.39 $ (0.44) $ 0.11
Mack-Cali Realty LP [Member]
Summary Of Condensed Quarterly Financial Information	  Quarter Ended 2018 December 31 September 30 June 30 March 31  Total revenues $ 132,936 $ 132,114 $ 126,589 $ 138,967  Net income $ 52,523 $ 1,689 $ 1,501 $ 50,688  Net income (loss) available to common unitholders $ 48,757 $ (1,645) $ (1,393) $ 47,919   Basic earnings per common unit:  Net income (loss) available to common unitholders $ 0.45 $ (0.05) $ (0.05) $ 0.45   Diluted earnings per common units:  Net income (loss) available to common unitholders $ 0.45 $ (0.05) $ (0.05) $ 0.45      Quarter Ended 2017 December 31 September 30 June 30 March 31  Total revenues $ 143,529 $ 160,018 $ 162,766 $ 149,887  Net income (loss) $ 5,411 $ 44,703 $ (39,125) $ 22,729  Net income (loss) available to common unitholders $ 2,881 $ 42,467 $ (41,626) $ 22,174   Basic earnings per common unit:  Net income (loss) available to common unitholders $ (0.01) $ 0.39 $ (0.44) $ 0.11   Diluted earnings per common unit:  Net income (loss) available to common unitholders $ (0.01) $ 0.39 $ (0.44) $ 0.11 

Organization And Basis Of Pre_2

Organization And Basis Of Presentation (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)ft²statepropertyitem	Dec. 31, 2017USD ($)
Real Estate Properties [Line Items]
Percentage of ownership interest	89.80%	89.60%
Number of properties owned or investment interests	135
Aggregate square feet of the property owned or investment interest | ft²	15,400,000
Number of units | item	1,317
Number of states where properties are located | state	6
Consolidated joint ventures, total real estate assets | $	$ 480.4	$ 215.5
Consolidated joint ventures, mortgages | $	241.5	81.2
Consolidated joint ventures, other liabilities | $	$ 23	$ 19.3
Commercial Properties [Member]
Real Estate Properties [Line Items]
Number of tenants | item	700
Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	24
Number of units | item	6,910
Office And Office/Flex Buildings [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	47
Aggregate square feet of the property owned or investment interest | ft²	2,700,000
Office [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	56
Aggregate square feet of the property owned or investment interest | ft²	12,600,000
Flex Properties [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	55
Unconsolidated Joint Venture Office Buildings [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	4
Aggregate square feet of the property owned or investment interest | ft²	500,000
Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	8
Number of units | item	2,922
Unconsolidated Joint Venture Office/Flex Buildings And Hotel [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	1
Parking/Retail [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	6
Aggregate square feet of the property owned or investment interest | ft²	137,100
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 | ft²	81,700
Land [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	1

Significant Accounting Polici_4

Significant Accounting Policies (Narrative) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 03, 2019	Jan. 03, 2018	Dec. 31, 2015
Significant Accounting Policies [Line Items]
Capitalized development and construction salaries and other related costs			$ 2,300,000	$ 2,200,000	$ 2,600,000
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		$ 0
Amortization of deferred financing costs			5,028,000	4,612,000	4,582,000
Loss from extinguishment of debt, net			(10,750,000)	(421,000)	12,420,000
Deferred leasing costs			3,463,000	3,146,000	3,270,000
Goodwill	2,945,000	$ 2,945,000	2,945,000	2,945,000
Goodwill impairment			0
Difference between the estimated net basis and net assets of the rental property for federal income tax purposes	410,573,000		410,573,000
Taxable income			82,106,000	$ 97,037,000	$ 30,208,000
Deferred tax asset	$ 10,100,000		10,100,000
Income taxes, material adjustment amount			$ 0
Common stock, shares outstanding	90,320,306	89,914,113	90,320,306	89,914,113			89,914,658
Common units outstanding	10,174,285	10,438,855	10,174,285	10,438,855	10,488,105		10,438,855	10,516,844
LTIP units outstanding	1,762,170	1,230,877	1,762,170	1,230,877	657,373		1,230,877
Distributions payable, record date	Jan. 3, 2019	Jan. 3, 2018
Distributions payable, approved date	Dec. 11, 2018	Dec. 12, 2017
Common stock dividends and common unit distributions per share	$ 0.20	$ 0.20
Dividends paid per common share			$ 0.80	$ 0.70	$ 0.60
Dividends paid, percent representing ordinary income			47.00%	100.00%
Dividends paid, percent representing return of capital to shareholders					100.00%
Dividends paid, percent representing capital gain			53.00%
Restricted stock expense			$ 6,894,000	$ 7,447,000	$ 5,646,000
Distributions payable, pay date	Jan. 11, 2019	Jan. 12, 2018
Increase (decrease) to deferred tax assets			(5,300,000)
Increase (decrease) to valuation allowance			$ (5,300,000)
Federal income tax rate			21.00%
Write off of unamortized deferred financing costs			$ 600,000	400,000	700,000
Loss from extinguishment of debt, net			$ (10,750,000)	$ (421,000)	$ (30,540,000)
Subsequent Event [Member]
Significant Accounting Policies [Line Items]
Common stock, shares outstanding						90,320,408
Common units outstanding						10,174,285
LTIP units outstanding						1,762,170

Significant Accounting Polici_5

Significant Accounting Policies (Schedule Of Rental Property Improvements) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Land held for development (including pre-development costs)	$ 465,930	$ 483,432
Development and construction in progress, including land	327,039	535,971
Total	792,969	1,019,403
Buildings and improvement	204,900	188,100
Development [Member]
Property, Plant and Equipment [Line Items]
Land	$ 49,600	$ 77,000

Significant Accounting Polici_6

Significant Accounting Policies (Estimated Useful Lives Of Assets) (Details)	12 Months Ended
	Dec. 31, 2018
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

Recent Transactions (Management

Recent Transactions (Management Changes) (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)	Mar. 15, 2018item	Mar. 14, 2018item
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 7.9
Restructuring costs related to stock compensation	1
Amortization of stock compensation	2
Number of board members | item		10	9
General and Administrative Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	6.5
Operating Services [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1.4

Recent Transactions (Acquisitio

Recent Transactions (Acquisitions) (Narrative) (Details) $ in Thousands	Jan. 25, 2019USD ($)item	Jan. 06, 2019USD ($)ft²	Dec. 31, 2018USD ($)item	Dec. 31, 2017USD ($)property	Dec. 31, 2016USD ($)
Real Estate Properties [Line Items]
Purchase price of property			$ 168,398	$ 90,068	$ 121,582
Number Of Units | item			1,317
Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number Of Units | item			6,910
Jersey City, New Jersey [Member] | Subsequent Event [Member]
Real Estate Properties [Line Items]
Purchase price of property	$ 264,000
Number Of Units | item	377
Iselin, New Jersey [Member] | Subsequent Event [Member]
Real Estate Properties [Line Items]
Area of property (in square feet) | ft²		271,988
Purchase price of property		$ 61,500
Jersey City, Morris Township And Red Bank, New Jersey [Member]
Real Estate Properties [Line Items]
Number of real estate properties | property				3
Purchase price of property				$ 80,000

Recent Transactions (Consolidat

Recent Transactions (Consolidations) (Narrative) (Details)	Aug. 02, 2018USD ($)item	Feb. 28, 2017USD ($)ft²itemshares	Feb. 03, 2017USD ($)shares	Apr. 30, 2017USD ($)shares	Dec. 31, 2018USD ($)item	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Aug. 01, 2018USD ($)	Feb. 27, 2017	Feb. 02, 2017
Real Estate Properties [Line Items]
Acquisition cost					$ 11,789,000	$ 36,060,000	$ 35,930,000
Consolidated joint ventures, total real estate assets					$ 480,400,000	215,500,000
Net assets acquired						$ 394,589,000
Percentage of ownership interest					89.80%	89.60%
Number of units | item					1,317
Purchase price of property					$ 168,398,000	$ 90,068,000	121,582,000
Gain on sale of investment in unconsolidated joint venture						23,131,000	5,670,000
Mortgage loan					45,242,000	45,734,000
Gain on change of control of interests					14,217,000		15,347,000
Issuance of loan					30,400,000
Loan balance					2,792,651,000	2,809,568,000
Noncontrolling interest's fair value					210,523,000	192,428,000
Mack-Cali Realty LP [Member]
Real Estate Properties [Line Items]
Acquisition cost					11,789,000	36,060,000	35,930,000
Purchase price of property					168,398,000	90,068,000	121,582,000
Gain on sale of investment in unconsolidated joint venture						$ 23,131,000	5,670,000
Gain on change of control of interests					14,217,000		$ 15,347,000
Plaza VIII & IX Associates, L.L.C. [Member]
Real Estate Properties [Line Items]
Percentage of interest in venture										50.00%
Percentage of additional interest acquired			12.50%
Acquisition cost			$ 14,300,000
Consolidated joint ventures, total real estate assets			$ 60,600,000
Monaco [Member]
Real Estate Properties [Line Items]
Number of towers | item		2
Net assets acquired					$ 139,886,000
Garage Parking Spaces | item		558
Number of stories | item		50
Area of property (in square feet) | ft²		12,300
Number of units | item		523
Marbella Tower Urban Renewal Associates LLC [Member]
Real Estate Properties [Line Items]
Percentage of interest in venture								24.27%
Percentage of additional interest acquired	50.00%
Number of units | item	412
Purchase price of property	$ 65,600,000
Mortgage loan, maturity date					Aug. 1, 2026
Spread over LIBOR	4.07%
Mortgage loan	$ 131,000,000							$ 95,000,000
Gain on change of control of interests					$ 14,200,000
Repayment of mortgage loans	$ 95,000,000
Issuance of loan					37,400,000
Loan balance					14,000,000
Noncontrolling interest's fair value					$ 29,800,000
Series A Units [Member] | Mack-Cali Realty LP [Member]
Real Estate Properties [Line Items]
Preferred units shares issued | shares			42,800
Percentage of interest in venture			37.50%
Preferred unit annual rate			3.50%
Preferred units aggregate amount			$ 42,800,000
Series A-1 Units [Member]
Real Estate Properties [Line Items]
Percentage of ownership interest		29.00%
Series A-1 Units [Member] | Mack-Cali Realty LP [Member]
Real Estate Properties [Line Items]
Preferred units shares issued | shares		9,213		91
Percentage of interest in venture		13.80%
Preferred unit annual rate		3.50%
Series A-1 Units [Member] | Monaco [Member]
Real Estate Properties [Line Items]
Percentage of interest in venture		29.00%							13.80%
Series A-1 Units [Member] | Monaco [Member] | Mack-Cali Realty LP [Member]
Real Estate Properties [Line Items]
Preferred units shares issued | shares		9,122		91
Percentage of interest in venture				71.20%
Preferred units aggregate amount		$ 9,100,000
Acquisition cost				$ 130,900,000
Debt assumed				$ 171,200,000

Recent Transactions (Other Inve

Recent Transactions (Other Investments In 2016) (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)item	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Recent Transactions [Abstract]
Purchase price of property | $	$ 168,398	$ 90,068	$ 121,582
Number of units | item	1,317

Recent Transactions (Dispositio

Recent Transactions (Dispositions/Rental Property Held for Sale) (Narrative) (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2019USD ($)item	Dec. 31, 2018USD ($)ft²propertyitem	Dec. 31, 2017USD ($)ft²propertyitem
Disposal Group, Not Discontinued Operations [Member]
Real Estate Properties [Line Items]
Unrealized losses on rental properties held for sale		$ (20,135)	$ (12,331)
Sales proceeds		$ 324,050	$ 399,332
Number of properties sold | item		30	60
Parsippany, Paramus, Rochelle Park, Hamilton And Wall, New Jersey And White Plains, New York [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Real Estate Properties [Line Items]
Assets held for sale, Deferred charges and other assets			$ 9,800
Assets held for sale, Unbilled rents receivable, net			4,700
Assets held for sale, Accounts payable, accrued expenses and other liabilities			4,600
Expected assets to be written off			13,400
Expected liabilities to be written off			$ 300
Parsippany, Paramus, Rochelle Park, Hamilton And Wall, New Jersey And White Plains, New York [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member]
Real Estate Properties [Line Items]
Area of property (in square feet) | ft²			2,000,000
Number of properties held for sale | property			21
Unrealized losses on rental properties held for sale			$ 12,300
Estimated expected sales proceeds			223,000
Sales proceeds			$ 12,300
Number of properties not expected to recover from estimated net sales proceeds | property			7
Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member] | Office [Member]
Real Estate Properties [Line Items]
Unrealized losses on rental properties held for sale		$ 20,100
Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Real Estate Properties [Line Items]
Assets held for sale, Deferred charges and other assets		2,900
Assets held for sale, Unbilled rents receivable, net		1,700
Assets held for sale, Accounts payable, accrued expenses and other liabilities		2,300
Expected assets to be written off		3,900
Expected liabilities to be written off		$ 1,700
Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member]
Real Estate Properties [Line Items]
Number of real estate properties | item		159
Area of property (in square feet) | ft²		845,000
Number of properties held for sale | property		6
Unrealized losses on rental properties held for sale		$ 20,100
Estimated expected sales proceeds		$ 124,000
Number of properties not expected to recover from estimated net sales proceeds | property		4
Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member] | Disposal Group, Not Discontinued Operations [Member] | Office [Member] | Subsequent Event [Member]
Real Estate Properties [Line Items]
Sales proceeds	$ 54,500
Number of properties sold | item	3

Recent Transactions (Land Impai

Recent Transactions (Land Impairments) (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)property
Property, Plant and Equipment [Line Items]
Land impairments | $	$ 24,566
Conshohocken And Bala Cynwyd, Pennsylvania [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Number of real estate properties | property	2

Recent Transactions (Rockpoint

Recent Transactions (Rockpoint Transaction) (Narrative) (Details) - USD ($) $ in Thousands	Mar. 10, 2017	Feb. 27, 2017	Dec. 31, 2018	Dec. 31, 2017
Preferred Units [Line Items]
Assets			$ 1,115,458	$ 1,139,322
Mortgages and loans payable			686,797	689,412
Other liabilities			67,072	80,746
RRLP [Member]
Preferred Units [Line Items]
Assets			2,300,000	1,900,000
Mortgages and loans payable			1,100,000	769,700
Other liabilities			57,000	$ 95,900
Investment Agreement [Member] | Rockpoint [Member]
Preferred Units [Line Items]
Incremental closing payments, Limited Partnership interest	$ 150,000		105,000
Investment Agreement [Member] | Rockpoint [Member] | Minimum [Member]
Preferred Units [Line Items]
Incremental closing payments, Limited Partnership interest			$ 10,000
Investment Agreement [Member] | Rockpoint [Member] | Maximum [Member]
Preferred Units [Line Items]
Contributed amount to obtain equity units		$ 300,000

Recent Transactions (Unconsolid

Recent Transactions (Unconsolidated Joint Venture Activity) (Narrative) (Details) $ in Thousands	Jan. 31, 2019USD ($)	Dec. 11, 2018USD ($)	Aug. 02, 2018USD ($)item	Sep. 29, 2017USD ($)	Sep. 21, 2017USD ($)	Feb. 15, 2017USD ($)	Jan. 31, 2017USD ($)	Dec. 31, 2018USD ($)ft²item	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Aug. 01, 2018USD ($)
Real Estate Properties [Line Items]
Gain (loss) on sale of investment in unconsolidated joint venture									$ 23,131	$ 5,670
Proceeds from the sale of investments in unconsolidated joint ventures									98,599	6,420
Investment in unconsolidated joint ventures								$ 11,789	36,060	35,930
Debt								$ 2,792,651
Number of units | item								1,317
Purchase price of property								$ 168,398	90,068	121,582
Mortgage loan								$ 45,242	$ 45,734
Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number of units | item								2,922
Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number of units | item								6,910
KP-MCG Curtis JV, LLC [Member]
Real Estate Properties [Line Items]
Gain (loss) on sale of investment in unconsolidated joint venture				$ 12,000
Proceeds from the sale of investments in unconsolidated joint ventures				102,500
Net sales proceeds held by qualified intermediary								$ 5,600
Debt				$ 75,000
KPG-P 100 IMW JV, LLC, Keystone-Penn And Keystone-Tristate [Member]
Real Estate Properties [Line Items]
Gain (loss) on sale of investment in unconsolidated joint venture							$ 7,400
Proceeds from the sale of investments in unconsolidated joint ventures							$ 9,700
Elmajo Urban Renewal Associates, LLC And Estuary Urban Renewal Associates, LLC [Member] | Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Gain (loss) on sale of investment in unconsolidated joint venture						$ 5,100
Proceeds from the sale of investments in unconsolidated joint ventures						$ 5,100
Percentage of interest in venture						7.50%
RoseGarden Monaco, L.L.C. [Member]
Real Estate Properties [Line Items]
Gain (loss) on sale of investment in unconsolidated joint venture					$ (1,400)
Metropolitan At 40 Park [Member]
Real Estate Properties [Line Items]
Purchase price of property		$ 1,300
Metropolitan At 40 Park [Member] | The Shops At 40 Park Property [Member]
Real Estate Properties [Line Items]
Area of property (in square feet) | ft²								50,973
Residual ownership interest		25.00%						12.50%
Mortgage loan								$ 6,100
Metropolitan At 40 Park [Member] | Lofts At 40 Park Property [Member]
Real Estate Properties [Line Items]
Number of stories | item								5
Number of units | item								59
Indirect ownership interest		50.00%						25.00%
Metropolitan At 40 Park [Member] | Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Percentage of interest in venture								25.00%
Number of units | item								130
Mortgage loan								$ 55,227
Marbella II [Member] | Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Percentage of interest in venture								24.27%
Number of units | item								311
Mortgage loan								$ 74,690
Marbella Tower Urban Renewal Associates LLC [Member]
Real Estate Properties [Line Items]
Percentage of interest in venture											24.27%
Percentage of additional interest acquired			50.00%
Number of units | item			412
Purchase price of property			$ 65,600
Repayment of mortgage loans			95,000
Mortgage loan			$ 131,000								$ 95,000
Subsequent Event [Member] | Marbella II [Member] | Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Mortgage loan	$ 117,000
Subsequent Event [Member] | Marbella Tower Urban Renewal Associates LLC [Member] | Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Percentage of interest in venture	50.00%
Purchase price of property	$ 77,500
Repayment of mortgage loans	74,700
Mortgage loan	$ 117,000

Recent Transactions (Schedule O

Recent Transactions (Schedule Of Properties Acquired) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)ft²item	Dec. 31, 2018USD ($)
Business Acquisition [Line Items]
Number of Buildings, Acquired | item	9
Rentable Square Feet, Acquired | ft²	1,392,500
Acquisition cost	$ 394,589,000
Loan balance	$ 2,809,568,000	$ 2,792,651,000
Red Bank Portfolio [Member]
Business Acquisition [Line Items]
Number of Buildings, Acquired | item	3
Rentable Square Feet, Acquired | ft²	279,472
Acquisition cost	$ 27,228,000
Short Hills / Madison Portfolio [Member]
Business Acquisition [Line Items]
Number of Buildings, Acquired | item	6
Rentable Square Feet, Acquired | ft²	1,113,028
Acquisition cost	$ 367,361,000
Unsecured Revolving Credit Facility [Member] | Short Hills / Madison Portfolio [Member]
Business Acquisition [Line Items]
Loan balance		$ 124,500,000

Recent Transactions (Schedule_2

Recent Transactions (Schedule Of Purchase Price Allocation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Land and leasehold interest		$ 38,250
Buildings and improvements and other assets		311,346
Above market leases		6,485
In-place lease values		48,775
Sub Total		404,856
Less: Below market lease values		(10,267)
Net Assets		$ 394,589
Above Market, In-Place And Below Market Leases [Member]
Business Acquisition [Line Items]
Amortization period		5 years 4 months 24 days
Red Bank Portfolio [Member]
Business Acquisition [Line Items]
Land and leasehold interest		$ 7,914
Buildings and improvements and other assets		16,047
Above market leases		118
In-place lease values		3,171
Sub Total		27,250
Less: Below market lease values		(22)
Net Assets		27,228
Short Hills / Madison Portfolio [Member]
Business Acquisition [Line Items]
Land and leasehold interest		30,336
Buildings and improvements and other assets		295,299
Above market leases		6,367
In-place lease values		45,604
Sub Total		377,606
Less: Below market lease values		(10,245)
Net Assets		$ 367,361
Marbella Tower Urban Renewal Associates LLC [Member]
Business Acquisition [Line Items]
Land and leasehold interest	$ 48,820
Buildings and improvements and other assets	162,958
In-place lease values	6,947
Sub Total	218,617
Less: Below market lease values	(108)
Non-controlling interest	22,812
Net Assets	$ 87,617
Marbella Tower Urban Renewal Associates LLC [Member] | In-Place And Below Market Leases [Member]
Business Acquisition [Line Items]
Amortization period	9 months 9 days

Recent Transactions (Schedule_3

Recent Transactions (Schedule Of Properties Which Commenced Initial Operations) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)item
Real Estate Properties [Line Items]
Number of Apartment Units | item	1,317
Total Development Costs Incurred	$ 457,984
Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number of Apartment Units | item	2,922
Unconsolidated Joint Venture Hotel [Member]
Real Estate Properties [Line Items]
Number of Apartment Units | item	350
145 Front At City Square [Member]
Real Estate Properties [Line Items]
Number of Apartment Units | item	365
Total Development Costs Incurred	$ 97,483
Signature Place At Morris Plains [Member]
Real Estate Properties [Line Items]
Number of Apartment Units | item	197
Total Development Costs Incurred	$ 56,715
Portside 5/6 [Member]
Real Estate Properties [Line Items]
Number of Apartment Units | item	296
Total Development Costs Incurred	$ 114,694
Expected costs	$ 700
Riverhouse 11 At Port Imperial [Member]
Real Estate Properties [Line Items]
Number of Apartment Units | item	295
Total Development Costs Incurred	$ 130,369
Expected costs	$ 1,200
Residence Inn By Marriott (Phase I) [Member]
Real Estate Properties [Line Items]
Number of Apartment Units | item	164
Total Development Costs Incurred	$ 58,723
Land [Member] | 145 Front At City Square [Member]
Real Estate Properties [Line Items]
Total Development Costs Incurred	4,400
Land [Member] | Signature Place At Morris Plains [Member]
Real Estate Properties [Line Items]
Total Development Costs Incurred	900
Construction Loan [Member] | 145 Front At City Square [Member]
Real Estate Properties [Line Items]
Expected costs	1,100
Construction Loan [Member] | Residence Inn By Marriott (Phase I) [Member]
Real Estate Properties [Line Items]
Expected costs	$ 20,100

Recent Transactions (Schedule_4

Recent Transactions (Schedule Of Net Assets Recorded Upon Consolidation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Land and leasehold interest		$ 38,250
Buildings and improvements and other assets, net		311,346
Above market leases		6,485
In-place lease values		48,775
Less: Below market lease values		(10,267)
Sub Total		404,856
Net Assets		$ 394,589
Above Market, In-Place And Below Market Leases [Member]
Business Acquisition [Line Items]
Amortization period		5 years 4 months 24 days
Marbella Tower Urban Renewal Associates LLC [Member]
Business Acquisition [Line Items]
Land and leasehold interest	$ 48,820
Buildings and improvements and other assets, net	162,958
In-place lease values	6,947
Less: Below market lease values	(108)
Sub Total	218,617
Less: Debt assumed at fair value	(131,000)
Net Assets	87,617
Less: Noncontrolling interest	(22,812)
Net assets recorded upon consolidation	$ 64,805
Marbella Tower Urban Renewal Associates LLC [Member] | In-Place And Below Market Leases [Member]
Business Acquisition [Line Items]
Amortization period	9 months 9 days
Distribution of loan proceeds	$ 7,000
Red Bank Portfolio [Member]
Business Acquisition [Line Items]
Land and leasehold interest		$ 7,914
Buildings and improvements and other assets, net		16,047
Above market leases		118
In-place lease values		3,171
Less: Below market lease values		(22)
Sub Total		27,250
Net Assets		27,228
Short Hills / Madison Portfolio [Member]
Business Acquisition [Line Items]
Land and leasehold interest		30,336
Buildings and improvements and other assets, net		295,299
Above market leases		6,367
In-place lease values		45,604
Less: Below market lease values		(10,245)
Sub Total		377,606
Net Assets		$ 367,361
Monaco North [Member]
Business Acquisition [Line Items]
Land and leasehold interest	27,300
Buildings and improvements and other assets, net	112,841
Above market leases	350
In-place lease values	4,585
Less: Below market lease values	(141)
Sub Total	144,935
Less: Debt assumed at fair value	(79,544)
Net Assets	65,391
Monaco South [Member]
Business Acquisition [Line Items]
Land and leasehold interest	31,461
Buildings and improvements and other assets, net	129,895
In-place lease values	4,913
Less: Below market lease values	(118)
Sub Total	166,151
Less: Debt assumed at fair value	(91,656)
Net Assets	74,495
Monaco [Member]
Business Acquisition [Line Items]
Land and leasehold interest	58,761
Buildings and improvements and other assets, net	242,736
Above market leases	350
In-place lease values	9,498
Less: Below market lease values	(259)
Sub Total	311,086
Less: Debt assumed at fair value	(171,200)
Net Assets	$ 139,886
Monaco [Member] | Above Market, In-Place And Below Market Leases [Member]
Business Acquisition [Line Items]
Amortization period	8 months

Recent Transactions (Schedule_5

Recent Transactions (Schedule Of Disposed Properties) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)ft²propertyitem	Dec. 31, 2017USD ($)ft²item	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Mar. 31, 2018USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
New mortgage loan/(repayments)		$ 44,695
Carrying Amount of Mortgages	$ 45,242	$ 45,734
Impairment charge	24,566
Valuation allowance	$ 10,100
Disposal Group, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	30	60
Rentable Square Feet, Disposed | ft²	2,405,654	4,677,058
Net Sales Proceeds	$ 324,050	$ 399,332
Net Carrying Value	204,479	384,637
Realized Gains (losses)/Unrealized Losses, net	119,571	14,695
Unrealized losses on rental properties held for sale	(20,135)	(12,331)
Totals	$ 99,436	$ 2,364
Disposal Group, Not Discontinued Operations [Member] | Cranford Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		6
Rentable Square Feet, Disposed | ft²		435,976
Net Sales Proceeds		$ 26,598
Net Carrying Value		22,736
Realized Gains (losses)/Unrealized Losses, net		$ 3,862
Disposal Group, Not Discontinued Operations [Member] | 440 Route 22 East [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		198,376
Net Sales Proceeds		$ 10,074
Net Carrying Value		10,069
Realized Gains (losses)/Unrealized Losses, net		$ 5
Impairment charge			$ 7,700
Disposal Group, Not Discontinued Operations [Member] | 3 Independence Way [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		111,300
Net Sales Proceeds		$ 11,549
Net Carrying Value		9,910
Realized Gains (losses)/Unrealized Losses, net		$ 1,639
Disposal Group, Not Discontinued Operations [Member] | 103 Carnegie Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		96,000
Net Sales Proceeds		$ 15,063
Net Carrying Value		8,271
Realized Gains (losses)/Unrealized Losses, net		$ 6,792
Disposal Group, Not Discontinued Operations [Member] | 400 Chestnut Ridge Road [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		89,200
Net Sales Proceeds		$ 6,891
Net Carrying Value		7,498
Realized Gains (losses)/Unrealized Losses, net		$ (607)
Disposal Group, Not Discontinued Operations [Member] | 140 East Ridgewood Avenue [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		239,680
Net Sales Proceeds		$ 30,201
Net Carrying Value		30,737
Realized Gains (losses)/Unrealized Losses, net		$ (536)
Disposal Group, Not Discontinued Operations [Member] | Bergen Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		5
Rentable Square Feet, Disposed | ft²		1,061,544
Net Sales Proceeds		$ 86,973
Net Carrying Value		135,121
Realized Gains (losses)/Unrealized Losses, net		(48,148)
Disposal Group, Not Discontinued Operations [Member] | Bergen Portfolio [Member] | Buyer [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Notes receivable		$ 65,000
Disposal Group, Not Discontinued Operations [Member] | 377 Summerhill Road [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		40,000
Net Sales Proceeds		$ 3,221
Net Carrying Value		2,172
Realized Gains (losses)/Unrealized Losses, net		1,049
Disposal Group, Not Discontinued Operations [Member] | 700 Executive Boulevard [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds		5,717
Net Carrying Value		970
Realized Gains (losses)/Unrealized Losses, net		$ 4,747
Disposal Group, Not Discontinued Operations [Member] | Totowa Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		13
Rentable Square Feet, Disposed | ft²		499,243
Net Sales Proceeds		$ 63,624
Net Carrying Value		27,630
Realized Gains (losses)/Unrealized Losses, net		$ 35,994
Disposal Group, Not Discontinued Operations [Member] | 890 Mountain Avenue [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		80,000
Net Sales Proceeds		$ 4,852
Net Carrying Value		6,139
Realized Gains (losses)/Unrealized Losses, net		$ (1,287)
Impairment charge				$ 7,000
Disposal Group, Not Discontinued Operations [Member] | 135 Chestnut Ridge Road [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		66,150
Net Sales Proceeds		$ 5,844
Net Carrying Value		2,929
Realized Gains (losses)/Unrealized Losses, net		2,915
Impairment charge				$ 4,200
Net sales proceeds held by qualified intermediary		$ 5,900
Disposal Group, Not Discontinued Operations [Member] | Moorestown Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		26
Rentable Square Feet, Disposed | ft²		1,260,398
Net Sales Proceeds		$ 73,393
Net Carrying Value		56,186
Realized Gains (losses)/Unrealized Losses, net		17,207
Net sales proceeds held by qualified intermediary		15,300
Disposal Group, Not Discontinued Operations [Member] | 1 Enterprise Boulevard [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds		3,230
Net Carrying Value		1,380
Realized Gains (losses)/Unrealized Losses, net		$ 1,850
Disposal Group, Not Discontinued Operations [Member] | 61 South Paramus Road [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		269,191
Net Sales Proceeds		$ 23,255
Net Carrying Value		37,184
Realized Gains (losses)/Unrealized Losses, net		$ (13,929)
Disposal Group, Not Discontinued Operations [Member] | 300 Tice Boulevard [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item		1
Rentable Square Feet, Disposed | ft²		230,000
Net Sales Proceeds		$ 28,847
Net Carrying Value		25,705
Realized Gains (losses)/Unrealized Losses, net		3,142
Disposal Group, Not Discontinued Operations [Member] | 35 Waterview Boulevard [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	1
Rentable Square Feet, Disposed | ft²	172,498
Net Sales Proceeds	$ 25,994
Net Carrying Value	25,739
Realized Gains (losses)/Unrealized Losses, net	$ 255
Valuation allowance		700
Disposal Group, Not Discontinued Operations [Member] | Hamilton Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	6
Rentable Square Feet, Disposed | ft²	239,262
Net Sales Proceeds	$ 17,546
Net Carrying Value	17,501
Realized Gains (losses)/Unrealized Losses, net	$ 45
Valuation allowance		600
Disposal Group, Not Discontinued Operations [Member] | Wall Portfolio First Closing [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	5
Rentable Square Feet, Disposed | ft²	179,601
Net Sales Proceeds	$ 14,053
Net Carrying Value	10,526
Realized Gains (losses)/Unrealized Losses, net	$ 3,527
Disposal Group, Not Discontinued Operations [Member] | 700 Horizon Drive [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	1
Rentable Square Feet, Disposed | ft²	120,000
Net Sales Proceeds	$ 33,020
Net Carrying Value	16,053
Realized Gains (losses)/Unrealized Losses, net	$ 16,967
Disposal Group, Not Discontinued Operations [Member] | Wall Portfolio Second Closing [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	3
Rentable Square Feet, Disposed | ft²	217,822
Net Sales Proceeds	$ 30,209
Net Carrying Value	12,961
Realized Gains (losses)/Unrealized Losses, net	$ 17,248
Disposal Group, Not Discontinued Operations [Member] | 75 Livingston Avenue [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	1
Rentable Square Feet, Disposed | ft²	94,221
Net Sales Proceeds	$ 7,983
Net Carrying Value	5,609
Realized Gains (losses)/Unrealized Losses, net	$ 2,374
Disposal Group, Not Discontinued Operations [Member] | 20 Waterview Boulevard [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	1
Rentable Square Feet, Disposed | ft²	225,550
Net Sales Proceeds	$ 12,475
Net Carrying Value	11,795
Realized Gains (losses)/Unrealized Losses, net	$ 680
Valuation allowance		$ 11,000
Disposal Group, Not Discontinued Operations [Member] | 20 Waterview Boulevard [Member] | Notes Receivable 6.0 Interest Rate [Member] | Buyer [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncash net sales proceeds					$ 2,800
Disposal Group, Not Discontinued Operations [Member] | Westchester Financial Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	2
Rentable Square Feet, Disposed | ft²	489,000
Net Sales Proceeds	$ 81,769
Net Carrying Value	64,679
Realized Gains (losses)/Unrealized Losses, net	17,090
Disposal Group, Not Discontinued Operations [Member] | Westchester Financial Center [Member] | Notes Receivable 3.0 Interest Rate [Member] | Buyer [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncash net sales proceeds	$ 4,000
Disposal Group, Not Discontinued Operations [Member] | 65 Jackson Drive [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	0
Net Sales Proceeds	$ 1,510
Realized Gains (losses)/Unrealized Losses, net	$ 1,510
Disposal Group, Not Discontinued Operations [Member] | 600 Horizon Drive [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	1
Rentable Square Feet, Disposed | ft²	95,000
Net Sales Proceeds	$ 15,127
Net Carrying Value	6,191
Realized Gains (losses)/Unrealized Losses, net	$ 8,936
Disposal Group, Not Discontinued Operations [Member] | 1 & 3 Barker Avenue [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	2
Rentable Square Feet, Disposed | ft²	133,300
Net Sales Proceeds	$ 15,140
Net Carrying Value	13,543
Realized Gains (losses)/Unrealized Losses, net	$ 1,597
Disposal Group, Not Discontinued Operations [Member] | 120 West Passaic Street [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	1
Rentable Square Feet, Disposed | ft²	52,000
Net Sales Proceeds	$ 2,667
Net Carrying Value	2,568
Realized Gains (losses)/Unrealized Losses, net	$ 99
Disposal Group, Not Discontinued Operations [Member] | Elmsford Distribution Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings, Disposed | item	6
Rentable Square Feet, Disposed | ft²	387,400
Net Sales Proceeds	$ 66,557
Net Carrying Value	17,314
Realized Gains (losses)/Unrealized Losses, net	$ 49,243
Land [Member] | Disposal Group, Not Discontinued Operations [Member] | Hamilton Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties disposed | property	2

Recent Transactions (Schedule_6

Recent Transactions (Schedule Of Disposed Developable Land) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total Development Costs Incurred	$ 457,984
Disposal Group, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds	46,036
Net Carrying Value	15,097
Gain on Disposition of Developable Land	30,939
1 Lake Street [Member] | Disposal Group, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds	46,036
Net Carrying Value	15,097
Gain on Disposition of Developable Land	30,939
Total Development Costs Incurred	$ 3,000

Recent Transactions (Summary Of

Recent Transactions (Summary Of Income From Property Held For Sale, Net) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Less - Accumulated depreciation	$ (1,097,868)	$ (1,087,083)
Rental property held for sale, net	108,848	171,578
Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Land	24,376
Buildings and improvements	159,857
Less - Accumulated depreciation	(55,250)
Less: Unrealized losses on properties held for sale	(20,135)
Rental property held for sale, net	$ 108,848
Parsippany, Paramus, Rochelle Park, Hamilton And Wall, New Jersey And White Plains, New York [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Land		37,024
Buildings and improvements		273,388
Less - Accumulated depreciation		(126,503)
Less: Unrealized losses on properties held for sale		(12,331)
Rental property held for sale, net		$ 171,578

Investments In Unconsolidated_3

Investments In Unconsolidated Joint Ventures (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)ft²propertyitem	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 232,750	$ 252,626
Number of units | item	1,317
Amount outstanding	$ 790,939	822,288
Management, leasing, development and other services fees	2,400	2,800
Accounts receivable due from unconsolidated joint ventures	200	800
Maximum exposure to loss	165,400
Estimated future funding commitments	35,800
Mortgage Loans on Real Estate	$ 45,242	$ 45,734
Unconsolidated Joint Venture Office Buildings [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | property	4
Area of property (in square feet) | ft²	500,000
Unconsolidated Joint Venture Retail Buildings [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | property	2
Area of mixed use project (in square feet) | ft²	81,700
Unconsolidated Joint Venture Multi-Family Properties [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | property	8
Number of units | item	2,922
Unconsolidated Joint Venture Hotel [Member]
Schedule of Equity Method Investments [Line Items]
Number of units | item	350
Unconsolidated Joint Venture Development Projects [Member]
Schedule of Equity Method Investments [Line Items]
Number of units | item	360
Unconsolidated Joint Venture Land Parcels [Member]
Schedule of Equity Method Investments [Line Items]
Number of units | item	3,738
Unconsolidated Joint Ventures [Member] | Guarantee of Indebtedness of Others [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	$ 316,900
Amount outstanding	204,900
Unconsolidated Joint Ventures [Member] | Parent Company [Member] | Guarantee of Indebtedness of Others [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	35,800
Amount outstanding	$ 24,600
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in venture	20.00%
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]
Carrying Value	$ 129,500
Number of VIEs | property	4

Investments In Unconsolidated_4

Investments In Unconsolidated Joint Ventures (Summary Of Unconsolidated Joint Ventures) (Details) $ in Thousands	Aug. 02, 2018USD ($)item	Aug. 01, 2018USD ($)item	Mar. 30, 2018USD ($)item	Feb. 03, 2017	Dec. 31, 2018USD ($)ft²item	Jan. 31, 2019USD ($)	Dec. 11, 2018	Dec. 31, 2017USD ($)	Feb. 15, 2017	Feb. 02, 2017	Dec. 31, 2016USD ($)
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					1,317
Carrying Value					$ 232,750			$ 252,626
Balance					45,242			45,734
Mortgage loan face amount					$ 41,695
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %					20.00%
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %					85.00%
Marbella Tower Urban Renewal Associates LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item	412
Company's Effective Ownership %		24.27%
Balance	$ 131,000	$ 95,000
Property Debt, Maturity Date					Aug. 1, 2026
Property Debt, Interest Rate, Spread Over LIBOR	4.07%
Percentage of additional interest acquired	50.00%
PI North - Riverwalk C [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity					$ 112,000
Marbella II [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Number of extension options | item			4
Loan extension period			3 months
Extension fee			0.0625%
Maximum borrowing capacity			$ 75,000
Urby At Harborside [Member] | Construction/Permanent Loan [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %					85.00%
Maximum borrowing capacity					$ 192,000
PI North - Land [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					836
Residual ownership interest					20.00%
Plaza VIII & IX Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %										50.00%
Percentage of additional interest acquired				12.50%
The Shops At 40 Park Property [Member] | Metropolitan At 40 Park [Member]
Schedule of Equity Method Investments [Line Items]
Rentable Square Feet (sf) | ft²					50,973
Balance					$ 6,100
Property Debt, Maturity Date					Sep. 1, 2019
Property Debt, Interest Rate, LIBOR					LIBOR+2.25
Property Debt, Interest Rate, Spread Over LIBOR					2.25%
Residual ownership interest					12.50%		25.00%
Lofts At 40 Park Property [Member] | Metropolitan At 40 Park [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					59
Indirect ownership interest					25.00%		50.00%
Number of stories | item					5
Lofts At 40 Park Property [Member] | Metropolitan At 40 Park [Member] | Construction Loan [Member]
Schedule of Equity Method Investments [Line Items]
Balance					$ 13,100
Property Debt, Maturity Date					Feb. 1, 2020
Property Debt, Interest Rate, Spread Over LIBOR					2.50%
Maximum borrowing capacity					$ 13,950
Metropolitan Property [Member] | Metropolitan At 40 Park [Member]
Schedule of Equity Method Investments [Line Items]
Balance					$ 36,000
Property Debt, Maturity Date					Sep. 1, 2020
Property Debt, Interest Rate					3.25%
Unconsolidated Joint Venture Multi-Family Properties [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					2,922
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella RoseGarden, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					412
Company's Effective Ownership %					24.27%
Carrying Value								14,544
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella Tower Urban Renewal Associates LLC [Member] | Subsequent Event [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %						50.00%
Balance						$ 117,000
Unconsolidated Joint Venture Multi-Family Properties [Member] | Metropolitan At 40 Park [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					130
Company's Effective Ownership %					25.00%
Carrying Value					$ 7,679			6,834
Balance					$ 55,227
Unconsolidated Joint Venture Multi-Family Properties [Member] | RiverTrace At Port Imperial [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					316
Company's Effective Ownership %					22.50%
Carrying Value					$ 8,112			8,864
Balance					$ 82,000
Property Debt, Maturity Date					Nov. 10, 2026
Property Debt, Interest Rate					3.21%
Unconsolidated Joint Venture Multi-Family Properties [Member] | Crystal House [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					825
Company's Effective Ownership %					25.00%
Carrying Value					$ 29,570			30,570
Balance					$ 162,838
Property Debt, Maturity Date					Apr. 1, 2020
Property Debt, Interest Rate					3.17%
Number of units available for development | item					295
Number of approved units available for development | item					252
Unconsolidated Joint Venture Multi-Family Properties [Member] | PI North - Riverwalk C [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					360
Company's Effective Ownership %					40.00%
Carrying Value					$ 27,175			16,844
Property Debt, Maturity Date					Dec. 6, 2021
Property Debt, Interest Rate, LIBOR					L+2.75
Property Debt, Interest Rate, Spread Over LIBOR					2.75%
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella II [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					311
Company's Effective Ownership %					24.27%
Carrying Value					$ 15,414			16,471
Balance					$ 74,690
Property Debt, Maturity Date					Mar. 30, 2019
Property Debt, Interest Rate, LIBOR					L+2.25
Property Debt, Interest Rate, Spread Over LIBOR					2.25%
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella II [Member] | Subsequent Event [Member]
Schedule of Equity Method Investments [Line Items]
Balance						$ 117,000
Unconsolidated Joint Venture Multi-Family Properties [Member] | Riverpark At Harrison [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					141
Company's Effective Ownership %					45.00%
Carrying Value					$ 1,272			1,604
Balance					$ 29,819
Property Debt, Maturity Date					Aug. 1, 2025
Property Debt, Interest Rate					3.70%
Unconsolidated Joint Venture Multi-Family Properties [Member] | Station House [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					378
Company's Effective Ownership %					50.00%
Carrying Value					$ 37,675			40,124
Balance					$ 98,504
Property Debt, Maturity Date					Jul. 1, 2033
Property Debt, Interest Rate					4.82%
Unconsolidated Joint Venture Multi-Family Properties [Member] | Urby At Harborside [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					762
Company's Effective Ownership %					85.00%
Carrying Value					$ 85,317			94,429
Balance					$ 191,732
Property Debt, Maturity Date					Aug. 1, 2029
Property Debt, Interest Rate					5.197%
Unconsolidated Joint Venture Multi-Family Properties [Member] | PI North - Land [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					836
Company's Effective Ownership %					20.00%
Carrying Value					$ 1,678			1,678
Unconsolidated Joint Venture Multi-Family Properties [Member] | Liberty Landing [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					850
Company's Effective Ownership %					50.00%
Carrying Value					$ 337			337
Unconsolidated Joint Venture Multi-Family Properties [Member] | Hillsborough 206 [Member]
Schedule of Equity Method Investments [Line Items]
Rentable Square Feet (sf) | ft²					160,000
Company's Effective Ownership %					50.00%
Carrying Value					$ 1,962			1,962
Unconsolidated Joint Venture Multi-Family Properties [Member] | Elmajo Urban Renewal Associates, LLC And Estuary Urban Renewal Associates, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %									7.50%
Unconsolidated Joint Venture Office Buildings [Member]
Schedule of Equity Method Investments [Line Items]
Rentable Square Feet (sf) | ft²					500,000
Unconsolidated Joint Venture Office Buildings [Member] | Red Bank [Member]
Schedule of Equity Method Investments [Line Items]
Rentable Square Feet (sf) | ft²					92,878
Company's Effective Ownership %					50.00%
Carrying Value					$ 3,127			4,602
Balance					$ 14,000
Property Debt, Maturity Date					Aug. 1, 2023
Property Debt, Interest Rate, LIBOR					L+2.25
Property Debt, Interest Rate, Spread Over LIBOR					2.25%
Number of extension options | item		2
Maximum borrowing capacity		$ 16,500
Unconsolidated Joint Venture Office Buildings [Member] | 12 Vreeland Road [Member]
Schedule of Equity Method Investments [Line Items]
Rentable Square Feet (sf) | ft²					139,750
Company's Effective Ownership %					50.00%
Carrying Value					$ 7,019			6,734
Balance					$ 7,904
Property Debt, Maturity Date					Jul. 1, 2023
Property Debt, Interest Rate					2.87%
Unconsolidated Joint Venture Office Buildings [Member] | Offices At Crystal Lake [Member]
Schedule of Equity Method Investments [Line Items]
Rentable Square Feet (sf) | ft²					106,345
Company's Effective Ownership %					31.25%
Carrying Value					$ 3,442			3,369
Balance					$ 4,076
Property Debt, Maturity Date					Nov. 1, 2023
Property Debt, Interest Rate					4.76%
Unconsolidated Joint Venture Other Property [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Value					$ 232,750			252,626
Balance					$ 820,790
Unconsolidated Joint Venture Other Property [Member] | Riverwalk Retail [Member]
Schedule of Equity Method Investments [Line Items]
Rentable Square Feet (sf) | ft²					30,745
Company's Effective Ownership %					20.00%
Carrying Value					$ 1,539			1,625
Unconsolidated Joint Venture Other Property [Member] | Hyatt Regency Jersey City [Member]
Schedule of Equity Method Investments [Line Items]
Number of Apartment Units | item					351
Company's Effective Ownership %					50.00%
Carrying Value					$ 112			440
Balance					$ 100,000
Property Debt, Maturity Date					Oct. 1, 2026
Property Debt, Interest Rate					3.668%
Unconsolidated Joint Venture Other Property [Member] | Other [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Value					$ 1,320			$ 1,595

Investments In Unconsolidated_5

Investments In Unconsolidated Joint Ventures (Summary Of Company's Equity In Earnings (Loss) Of Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	$ (127)	$ (6,081)	$ 18,788
Amortization of basis difference	903	792	436
Hillsborough 206 [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	16	(25)	(53)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella I [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	205	334	231
Unconsolidated Joint Venture Multi-Family Properties [Member] | Metropolitan At 40 Park [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(455)	(311)	(317)
Unconsolidated Joint Venture Multi-Family Properties [Member] | RiverTrace At Port Imperial [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	154	196	(1,146)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Crystal House [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(874)	(923)	(870)
Unconsolidated Joint Venture Multi-Family Properties [Member] | PI North Pier Land [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(126)	(219)	(62)
Unconsolidated Joint Venture Multi-Family Properties [Member] | PI North - Riverwalk C [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures		(653)	(58)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella II [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	35	93	(202)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Riverpark At Harrison [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(232)	(252)	(190)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Station House [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(2,096)	(1,793)	(2,440)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Urby At Harborside [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(975)	(6,356)	(219)
Economic tax credit certificate income	$ 2,600
Period of venture agreement to sell economic tax credit	9 years
Annual proceeds from economic tax credit	$ 3,000
Total proceeds from economic tax credit	27,000
Unconsolidated Joint Venture Multi-Family Properties [Member] | Liberty Landing [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(5)	(15)	(80)
Unconsolidated Joint Venture Office Buildings [Member] | Red Bank [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(215)	238	448
Unconsolidated Joint Venture Office Buildings [Member] | 12 Vreeland Road [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	285	496	347
Unconsolidated Joint Venture Office Buildings [Member] | Offices At Crystal Lake [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	73	89	(15)
Unconsolidated Joint Venture Other Property [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(127)	(6,081)	18,788
Unconsolidated Joint Venture Other Property [Member] | Roseland/North Retail, L.L.C./ Riverwalk At Port Imperial [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	(86)	(81)	(52)
Unconsolidated Joint Venture Other Property [Member] | South Pier At Harborside / Hyatt Regency Jersey City On The Hudson [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	3,672	3,277	24,180
Unconsolidated Joint Venture Other Property [Member] | Other [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings of unconsolidated joint ventures	$ 497	$ (176)	$ (714)

Investments In Unconsolidated_6

Investments In Unconsolidated Joint Ventures (Summary Of Financial Position Of Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Investments In Unconsolidated Joint Ventures [Abstract]
Rental property, net	$ 903,253	$ 931,419
Other assets	212,205	207,903
Total assets	1,115,458	1,139,322
Mortgages and loans payable	686,797	689,412
Other liabilities	67,072	80,746
Partners'/members' capital	361,589	369,164
Total liabilities and partners'/members' capital	$ 1,115,458	$ 1,139,322

Investments In Unconsolidated_7

Investments In Unconsolidated Joint Ventures (Summary Of Results Of Operations Of Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments In Unconsolidated Joint Ventures [Abstract]
Total revenues	$ 310,919	$ 358,751	$ 377,711
Operating and other expenses	(230,863)	(297,492)	(262,703)
Depreciation and amortization	(40,193)	(31,020)	(75,512)
Interest expense	(34,874)	(25,822)	(58,390)
Net income (loss)	$ 4,989	$ 4,417	$ (18,894)

Deferred Charges, Goodwill An_3

Deferred Charges, Goodwill And Other Assets, Net (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Credit Risk Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net liability	$ 0
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	675,000,000
Ineffective gain (loss) in interest expense	(200,000)	$ (37,000)	$ 600,000
Estimated additional amount to be reclassified to interest expense	$ 6,700,000
Not Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of increase in the fair value of derivatives			$ 2,000

Deferred Charges, Goodwill An_4

Deferred Charges, Goodwill And Other Assets, Net (Schedule Of Deferred Charges, Goodwill And Other Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Aug. 31, 2017
Deferred Charges, Goodwill And Other Assets [Line Items]
Deferred leasing costs	$ 173,822	$ 199,515
Deferred financing costs - unsecured revolving credit facility	5,356	4,945
Deferred charges, net	179,178	204,460
Accumulated amortization	(71,326)	(98,956)
Deferred charges, net	107,852	105,504
Notes receivable	47,409	50,167
In-place lease values, related intangibles and other assets, net	89,860	102,757
Goodwill	2,945	2,945
Prepaid expenses and other assets, net	107,168	80,947
Total deferred charges, goodwill and other assets, net	355,234	342,320
Acquired Above And Below Market Lease Intangibles [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Lease revenue	5,300	7,900	$ 1,900
Acquisition-related Costs [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Net sales proceeds held by qualified intermediary	$ 49,200	26,900
Notes Receivable 5.85 Interest Rate [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Notes receivable		45,700
Mortgage loan, maturity date	Jul. 1, 2019
Interest rate	5.85%
Notes receivable	$ 45,200			$ 44,700
Loan extension period	3 months
Interest-Free Notes Receivable [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Mortgage loan, maturity date	Apr. 1, 2023
Notes receivable	$ 2,200	2,500
Disposal Group, Not Discontinued Operations [Member] | Buyer [Member] | Bergen Portfolio [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Notes receivable		$ 65,000

Deferred Charges, Goodwill An_5

Deferred Charges, Goodwill And Other Assets (Summary Of Scheduled Amortization) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
2,019	$ 2,491
2,020	1,928
2,021	1,941
2,022	1,932
2,023	2,072
Acquired Above Market Lease [Member]
Finite-Lived Intangible Assets [Line Items]
2,019	(2,559)
2,020	(2,377)
2,021	(2,245)
2,022	(2,132)
2,023	(1,207)
Acquired Below-Market Lease Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
2,019	5,050
2,020	4,305
2,021	4,186
2,022	4,064
2,023	3,279
In-Place Leases [Member]
Finite-Lived Intangible Assets [Line Items]
2,019	10,494
2,020	8,050
2,021	6,884
2,022	6,059
2,023	4,943
Amortization expense	$ 17,900	$ 32,200	$ 14,300

Deferred Charges, Goodwill An_6

Deferred Charges, Goodwill And Other Assets, Net (Schedule Of Fair Value Of The Derivative Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member] | Deferred Charges, Goodwill And Other Assets [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	$ 10,175	$ 8,060

Deferred Charges, Goodwill An_7

Deferred Charges, Goodwill And Other Assets, Net (Schedule Of Cash Flow Hedging, Derivative Financial Instruments On The Income Statement) (Details) - Not Designated as Hedging Instrument [Member] - Cash Flow Hedging [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ 2,944	$ (2,381)	$ (3,398)
Interest And Other Investment Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion, Reclassification for Forecasted Transactions No Longer Probable of Occurring and Amount Excluded from Effectiveness Testing)	(204)	(37)	631
Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)	$ 5,262	$ 2,869	$ (1,183)

Restricted Cash (Schedule Of Re

Restricted Cash (Schedule Of Restricted Cash) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted Cash [Abstract]
Security deposits	$ 10,257	$ 9,446
Escrow and other reserve funds	9,664	30,346
Total restricted cash	$ 19,921	$ 39,792	$ 53,952	$ 35,343

Senior Unsecured Notes (Summary

Senior Unsecured Notes (Summary Of Senior Unsecured Notes) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Principal balance outstanding	$ 2,792,651,000	$ 2,809,568,000
Adjustment for unamortized debt discount	(2,838,000)
Total senior unsecured notes, net	$ 2,792,651,000
4.500% Senior Unsecured Notes Due April 18, 2022 [Member]
Debt Instrument [Line Items]
Interest rate of senior unsecured notes	4.50%
Maturity date of the senior unsecured notes	Apr. 18, 2022
3.150% Senior Unsecured Notes, Due May 15, 2023 [Member]
Debt Instrument [Line Items]
Interest rate of senior unsecured notes	3.15%
Maturity date of the senior unsecured notes	May 15, 2023
Unsecured Note [Member]
Debt Instrument [Line Items]
Principal balance outstanding	$ 575,000,000	575,000,000
Adjustment for unamortized debt discount	(2,838,000)	(3,505,000)
Unamortized deferred financing costs	(1,848,000)	(2,350,000)
Total senior unsecured notes, net	570,314,000	569,145,000
Unsecured Note [Member] | 4.500% Senior Unsecured Notes Due April 18, 2022 [Member]
Debt Instrument [Line Items]
Principal balance outstanding	$ 300,000,000	300,000,000
Effective rate	4.612%
Unsecured Note [Member] | 3.150% Senior Unsecured Notes, Due May 15, 2023 [Member]
Debt Instrument [Line Items]
Principal balance outstanding	$ 275,000,000	$ 275,000,000
Effective rate	3.517%

Unsecured Revolving Credit Fa_3

Unsecured Revolving Credit Facility And Term Loans (Narrative) (Details)	Jan. 07, 2019USD ($)item	Mar. 06, 2018	Jan. 25, 2017USD ($)entity	Dec. 31, 2018USD ($)item	Dec. 31, 2016USD ($)item	Dec. 31, 2017USD ($)	Mar. 29, 2017	Mar. 22, 2017USD ($)	Jan. 26, 2017USD ($)	Jan. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Loan balance				$ 2,792,651,000		$ 2,809,568,000
Outstanding borrowings under the facility				790,939,000		822,288,000
Unsecured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Number of lending institutions | item					17
Borrowing capacity under the credit facility					$ 600,000,000
Outstanding borrowings under the facility				$ 117,000,000		150,000,000
2017 Credit Agreement [Member]
Line of Credit Facility [Line Items]
Number of lending institutions | entity			13
Borrowing capacity under the credit facility			$ 60,000,000
Terms of the unsecured facility				The 2017 Credit Agreement, which applies to both the 2017 Credit Facility and 2017 Term Loan, includes 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 2017 Credit Agreement (described below), or (ii) the property dispositions are completed while the Company is under an event of default under the 2017 Credit Agreement, 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 entire outstanding balance under the 2017 Credit Agreement may (or, in the case of any bankruptcy event of default, shall) become immediately due and payable, and the Company will not make any excess distributions except to enable the General Partner to continue to qualify as a REIT under the IRS Code.
Spread over LIBOR		1.30%
2017 Credit Facility [Member]
Line of Credit Facility [Line Items]
Loan maturity date				Jan. 1, 2021
Borrowing capacity under the credit facility			600,000,000
Number of extension options | item				2
Credit facility, extension period				6 months
Terms of the unsecured facility				The terms of the 2017 Credit Facility include: (1) a four-year term ending in January 2021, with two six-month extension options; (2) revolving credit loans may be made to the Company in an aggregate principal amount of up to $600 million (subject to increase as discussed below), with a sublimit under the 2017 Credit Facility for the issuance of letters of credit in an amount not to exceed $60 million (subject to increase as discussed below); (3) an interest rate, based on the Operating Partnership's unsecured debt ratings from Moody's or S&P, or, at the Operating Partnership's option, if it no longer maintains a debt rating from Moody's or S&P or such debt ratings fall below Baa3 and BBB-, based on a defined leverage ratio; and (4) a facility fee, currently 25 basis points, payable quarterly based on the Operating Partnership's unsecured debt ratings from Moody's or S&P, or, at the Operating Partnership's option, if it no longer maintains a debt rating from Moody's or S&P or such debt ratings fall below Baa3 and BBB-, based on a defined leverage ratio.
Loan period				4 years
Facility fee basis points				0.25%
2017 Credit Agreement, Letter Of Credit [Member]
Line of Credit Facility [Line Items]
Maximum loan increase that may be requested									$ 100,000,000
2017 Credit Agreement Amendment And 2016 Term Loan Amendment [Member]
Line of Credit Facility [Line Items]
Terms of the unsecured facility				On August 30, 2018, the Company entered into an amendment to the 2017 Credit Agreement (the "2017 Credit Agreement Amendment") and an amendment to the 2016 Term Loan (the "2016 Term Loan Amendment"). Each of the 2017 Credit Agreement Amendment and the 2016 Term Loan Amendment is effective as of June 30, 2018 and provides for the following material amendments to the terms of both the 2017 Credit Agreement and 2016 Term Loan):The unsecured debt ratio covenant has been modified with respect to the measurement of the unencumbered collateral pool of assets in the calculation of such ratio for the period commencing July 1, 2018 and continuing until December 31, 2019 to allow the Operating Partnership to utilize the "as-is" appraised value of the properties known as ‘Harborside Plaza I' and ‘Harborside Plaza V' properties located in Jersey City, NJ in such calculation; andA new covenant has been added that prohibits the Company from making any optional or voluntary payment, repayment, repurchase or redemption of any unsecured indebtedness of the Company (or any subsidiaries) that matures after January 25, 2022, at any time when any of the Total Leverage Ratio or the unsecured debt ratio covenants exceeds 60 percent (all as defined in the 2017 Credit Agreement and the 2016 Term Loan) or an appraisal is being used to determine the value of Harborside Plaza I and Harborside Plaza V for the unsecured debt ratio covenant.
Unsecured Term Loan [Member] | Unsecured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding borrowings under the facility				$ 790,900,000		822,300,000
5.800% Senior Unsecured Notes, Due January 15, 2016 [Member]
Line of Credit Facility [Line Items]
Loan balance										$ 200,000,000
Loan maturity date				Jan. 15, 2016
2017 Term Loan [Member]
Line of Credit Facility [Line Items]
Loan balance								$ 325,000,000
Loan maturity date				Jan. 1, 2020
Unamortized deferred financing costs				$ 1,100,000		1,700,000
Loan extension period				1 year
Interest rate swap							1.6473%
Interest rate							3.1973%
Borrowing capacity under the credit facility			$ 325,000,000
Number of extension options | item				2
Terms of the unsecured facility				The terms of the 2017 Term Loan include: (1) a three-year term ending in January 2020, with two one-year extension options; (2) multiple draws of the term loan commitments may be made within 12 months of the effective date of the 2017 Credit Agreement up to an aggregate principal amount of $325 million (subject to increase as discussed below), with no requirement to be drawn in full; provided, that, if the Company does not borrow at least 50 percent of the initial term commitment from the term lenders (i.e. 50 percent of $325 million) on or before July 25, 2017, the amount of unused term loan commitments shall be reduced on such date so that, after giving effect to such reduction, the amount of unused term loan commitments is not greater than the outstanding term loans on such date; (3) an interest rate based on the Operating Partnership's unsecured debt ratings from Moody's or S&P, or, at the Operating Partnership's option if it no longer maintains a debt rating from Moody's or S&P or such debt ratings fall below Baa3 and BBB-, based on a defined leverage ratio; and (4) a term commitment fee on any unused term loan commitment during the first 12 months after the effective date of the 2017 Credit Agreement at a rate of 0.25 percent per annum on the sum of the average daily unused portion of the aggregate term loan commitments.
Outstanding borrowings under the facility				$ 323,900,000		323,300,000
Spread over LIBOR		1.55%
Loan period				3 years
Minimum percentage of initial borrowing				50.00%
Term commitment fee percent				0.25%
Incremental Commitments [Member]
Line of Credit Facility [Line Items]
Maximum loan increase that may be requested									$ 350,000,000
2016 Term Loan [Member]
Line of Credit Facility [Line Items]
Unsecured term loan, net										$ 350,000,000
Loan maturity date				Jan. 1, 2019
Unamortized deferred financing costs						1,000,000
Interest rate				3.28%
Credit facility maturity date				Jan. 1, 2020
Number of extension options | item				2
Credit facility, extension period				1 year
Terms of the unsecured facility				The terms of the 2016 Term Loan 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 term loan described below, or (ii) the property dispositions are completed while the Company is under an event of default under the term loan, 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 General Partner to continue to qualify as a REIT under the IRS Code.
Outstanding borrowings under the facility				$ 350,000,000		$ 349,000,000
Spread over LIBOR		1.55%
Subsequent Event [Member] | 2016 Term Loan [Member]
Line of Credit Facility [Line Items]
Extension fee amount	$ 500,000
Number of extensions exercised | item	1

Unsecured Revolving Credit Fa_4

Unsecured Revolving Credit Facility And Term Loans (Schedule Of Defined Leverage Ratio, Including Interest Rate, Alternate Base Rate Loans, And Facility Fee) (Details) - 2017 Credit Facility [Member]	12 Months Ended
	Dec. 31, 2018
Debt Instrument [Line Items]
Facility Fee Basis Points	0.25%
45% Unsecured Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.25%
Facility Fee Basis Points	0.20%
45% Unsecured Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	45.00%
45% And 50% Unsecured Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.30%
Facility Fee Basis Points	0.25%
45% And 50% Unsecured Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	45.00%
45% And 50% Unsecured Term Loan Leverage Ratio [Member] | Maximum [Member]
Debt Instrument [Line Items]
Leverage ratio	50.00%
50% And 55% Unsecured Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.35%
Facility Fee Basis Points	0.30%
50% And 55% Unsecured Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	50.00%
50% And 55% Unsecured Term Loan Leverage Ratio [Member] | Maximum [Member]
Debt Instrument [Line Items]
Leverage ratio	55.00%
55% Unsecured Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.60%
Facility Fee Basis Points	0.35%
55% Unsecured Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	55.00%
Base Rate [Member] | 45% Unsecured Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.25%
Base Rate [Member] | 45% And 50% Unsecured Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.30%
Base Rate [Member] | 50% And 55% Unsecured Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.35%
Base Rate [Member] | 55% Unsecured Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.60%

Unsecured Revolving Credit Fa_5

Unsecured Revolving Credit Facility And Term Loans (Schedule Of Interest Rates On Outstanding Borrowings, Alternate Base Rate Loans, And Facility Fee) (Details) - 2017 Credit Facility [Member]	12 Months Ended
	Dec. 31, 2018
Line of Credit Facility [Line Items]
Facility Fee Basis Points	0.25%
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	1.55%
Facility Fee Basis Points	0.30%
Baa3 [Member] | BBB- [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings	BBB- or Baa3 (interest rate based on Company's election through March 5, 2018)
Interest Rate - Applicable Basis Points Above LIBOR	1.20%
Facility Fee Basis Points	0.25%
Baa2 [Member] | BBB [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings	BBB or Baa2
Interest Rate - Applicable Basis Points Above LIBOR	1.00%
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	0.90%
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	0.875%
Facility Fee Basis Points	0.125%
Base Rate [Member] | No Ratings Or Less Than Baa3 [Member] | No Ratings Or Less Than BBB- [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.55%
Base Rate [Member] | Baa3 [Member] | BBB- [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.20%
Base Rate [Member] | Baa2 [Member] | BBB [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.00%
Base Rate [Member] | Baa1 [Member] | BBB+ [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.00%
Base Rate [Member] | A3 Or Higher [Member] | A- Or Higher [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.00%

Unsecured Revolving Credit Fa_6

Unsecured Revolving Credit Facility And Term Loans (Schedule Of Unsecured Credit Rating And Facility Fee) (Details) - Unsecured Revolving Credit Facility [Member]	12 Months Ended
	Dec. 31, 2018
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 (since January 2017 amendment)
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	0.925%
Facility Fee Basis Points	0.125%

Unsecured Revolving Credit Fa_7

Unsecured Revolving Credit Facility And Term Loans (Schedule Of Defined Leverage Ratio) (Details)	12 Months Ended
	Dec. 31, 2018
45% Unsecured 2017 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.45%
45% Unsecured 2017 Term Loan Leverage Ratio [Member] | Maximum [Member]
Debt Instrument [Line Items]
Leverage ratio	45.00%
45% And 50% Unsecured 2017 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.55%
45% And 50% Unsecured 2017 Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	45.00%
45% And 50% Unsecured 2017 Term Loan Leverage Ratio [Member] | Maximum [Member]
Debt Instrument [Line Items]
Leverage ratio	50.00%
50% And 55% Unsecured 2017 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.65%
50% And 55% Unsecured 2017 Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	50.00%
50% And 55% Unsecured 2017 Term Loan Leverage Ratio [Member] | Maximum [Member]
Debt Instrument [Line Items]
Leverage ratio	55.00%
55% Unsecured 2017 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.95%
55% Unsecured 2017 Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	55.00%
45% Unsecured 2016 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.45%
45% Unsecured 2016 Term Loan Leverage Ratio [Member] | Maximum [Member]
Debt Instrument [Line Items]
Leverage ratio	45.00%
45% And 50% Unsecured 2016 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.55%
45% And 50% Unsecured 2016 Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	45.00%
45% And 50% Unsecured 2016 Term Loan Leverage Ratio [Member] | Maximum [Member]
Debt Instrument [Line Items]
Leverage ratio	50.00%
50% And 55% Unsecured 2016 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.65%
50% And 55% Unsecured 2016 Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	50.00%
50% And 55% Unsecured 2016 Term Loan Leverage Ratio [Member] | Maximum [Member]
Debt Instrument [Line Items]
Leverage ratio	55.00%
55% Unsecured 2016 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.95%
55% Unsecured 2016 Term Loan Leverage Ratio [Member] | Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio	55.00%
Base Rate [Member] | 45% Unsecured 2017 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.45%
Base Rate [Member] | 45% And 50% Unsecured 2017 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.55%
Base Rate [Member] | 50% And 55% Unsecured 2017 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.65%
Base Rate [Member] | 55% Unsecured 2017 Term Loan Leverage Ratio [Member]
Debt Instrument [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	0.95%

Unsecured Revolving Credit Fa_8

Unsecured Revolving Credit Facility And Term Loans (Schedule Of Interest Rate On Outstanding Borrowings Payable) (Details)	Mar. 06, 2018	Dec. 31, 2018
2017 Term Loan [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.55%
2016 Term Loan [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR	1.55%
No Ratings Or Less Than Baa3 [Member] | 2017 Term Loan [Member] | No Ratings Or Less Than BBB- [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings		No ratings or less than BBB-/Baa3
No Ratings Or Less Than Baa3 [Member] | 2016 Term Loan [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		1.85%
Baa3 [Member] | 2017 Term Loan [Member] | BBB- [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings		BBB- or Baa3 (interest rate based on Company's election through March 5, 2018)
Baa3 [Member] | 2016 Term Loan [Member] | BBB- [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings		BBB- or Baa3 (interest rate based on Company's election through March 5, 2018)
Interest Rate - Applicable Basis Points Above LIBOR		1.40%
Baa2 [Member] | 2017 Term Loan [Member] | BBB [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings		BBB or Baa2
Baa2 [Member] | 2016 Term Loan [Member] | BBB [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings		BBB or Baa2
Interest Rate - Applicable Basis Points Above LIBOR		1.15%
Baa1 [Member] | 2017 Term Loan [Member] | BBB+ [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings		BBB+ or Baa1
Baa1 [Member] | 2016 Term Loan [Member] | BBB+ [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings		BBB+ or Baa1
Interest Rate - Applicable Basis Points Above LIBOR		1.00%
A3 Or Higher [Member] | 2017 Term Loan [Member] | A- Or Higher [Member]
Line of Credit Facility [Line Items]
Unsecured Debt Ratings		A- or A3 or higher
A3 Or Higher [Member] | 2016 Term Loan [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		0.90%
Base Rate [Member] | No Ratings Or Less Than Baa3 [Member] | 2016 Term Loan [Member] | No Ratings Or Less Than BBB- [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR		0.85%
Base Rate [Member] | Baa3 [Member] | 2016 Term Loan [Member] | BBB- [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR		0.40%
Base Rate [Member] | Baa2 [Member] | 2016 Term Loan [Member] | BBB [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR		0.15%
Base Rate [Member] | Baa1 [Member] | 2016 Term Loan [Member] | BBB+ [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR		0.00%
Base Rate [Member] | A3 Or Higher [Member] | 2016 Term Loan [Member] | A- Or Higher [Member]
Line of Credit Facility [Line Items]
Interest Rate - Applicable Basis Points Above LIBOR		0.00%

Mortgages, Loans Payable And _3

Mortgages, Loans Payable And Other Obligations (Narrative) (Details)	12 Months Ended
	Dec. 31, 2018USD ($)propertyitem	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Cash paid for interest	$ 97,744,000	$ 103,559,000	$ 122,414,000
Interest capitalized	27,047,000	20,240,000	19,316,000
Total indebtedness	2,792,651,000
Adjusted total indebtedness	$ 2,807,396,000	$ 2,826,110,000
Total indebtedness, weighted average interest rate	3.89%	3.93%
Projects Under Development And Developable Land [Member]
Debt Instrument [Line Items]
Number of projects with encumbered company mortgages | item	1
Carrying value of encumbered properties	$ 142,000,000
Other Property [Member]
Debt Instrument [Line Items]
Number of properties with encumbered company mortgages | property	16
Carrying value of encumbered properties	$ 2,100,000,000
Unconsolidated Joint Venture [Member]
Debt Instrument [Line Items]
Interest capitalized	816,000	$ 1,056,000	$ 5,055,000
Revolving Credit Facility Borrowing And Other Variable Rate Mortgage Debt [Member]
Debt Instrument [Line Items]
Total indebtedness	$ 314,177,000	$ 382,443,000
Total indebtedness, weighted average interest rate	4.90%	3.63%
Fixed Rate Debt And Other Obligations [Member]
Debt Instrument [Line Items]
Total indebtedness	$ 2,493,219,000	$ 2,443,667,000
Total indebtedness, weighted average interest rate	3.76%	3.98%

Mortgages, Loans Payable And _4

Mortgages, Loans Payable And Other Obligations (Summary Of Mortgages, Loans Payable And Other Obligations) (Details)	Dec. 17, 2018USD ($)	Dec. 07, 2018USD ($)	Mar. 29, 2018USD ($)	Mar. 01, 2018USD ($)	Jan. 08, 2018USD ($)	Dec. 31, 2018USD ($)propertyitem	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Principal balance outstanding						$ 2,792,651,000	$ 2,809,568,000
Adjustment for unamortized debt discount						2,838,000
Borrowings from revolving credit facility						461,000,000	730,000,000	$ 1,165,000,000
Payment for borrowings						$ 494,000,000	866,000,000	$ 1,034,000,000
250 Johnson Road [Member]
Debt Instrument [Line Items]
Loan maturity date						May 20, 2019
Portside 5/6 [Member]
Debt Instrument [Line Items]
Loan maturity date						Mar. 10, 2026
Secured Debt [Member]
Debt Instrument [Line Items]
Principal balance outstanding						$ 1,440,396,000	1,426,111,000
Unamortized deferred financing costs						8,998,000	7,976,000
Total mortgages, loans payable and other obligations, net						$ 1,431,398,000	1,418,135,000
Secured Debt [Member] | Curtis Center [Member]
Debt Instrument [Line Items]
Property Name						Harborside Plaza
Lender						The Northwestern Mutual Life Insurance & New York Life Insurance Co.
Effective rate						6.84%
Principal balance outstanding							209,257,000
Secured Debt [Member] | Chase II [Member]
Debt Instrument [Line Items]
Lender						& New York Life Insurance Co.
Principal balance outstanding
Secured Debt [Member] | Harborside Plaza 5 [Member]
Debt Instrument [Line Items]
Payment for borrowings					$ 8,400,000
Secured Debt [Member] | 23 Main Street [Member]
Debt Instrument [Line Items]
Property Name						23 Main Street
Lender						Berkadia CMBS
Effective rate						5.59%
Principal balance outstanding							27,090,000
Payment for borrowings				$ 100,000
Secured Debt [Member] | One River Center [Member]
Debt Instrument [Line Items]
Property Name						One River Center
Lender						Guardian Life Insurance Co.
Effective rate						7.31%
Principal balance outstanding							40,485,000
Number of properties used to collateralized mortgage | property						3
Payment for borrowings			$ 1,800,000
Secured Debt [Member] | Park Square [Member]
Debt Instrument [Line Items]
Property Name						Park Square
Lender						Wells Fargo Bank N.A.
LIBOR						LIBOR+1.87
Effective rate						1.87%
Principal balance outstanding						$ 25,167,000	26,567,000
Loan maturity date						Apr. 10, 2019
Secured Debt [Member] | 250 Johnson Road [Member]
Debt Instrument [Line Items]
Property Name						250 Johnson
Lender						M&T Bank
LIBOR						LIBOR+2.35
Effective rate						2.35%
Principal balance outstanding						$ 41,769,000	32,491,000
Secured Debt [Member] | 250 Johnson Road [Member] | Construction Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 42,000,000
Loan extension period						1 year
Extension fee						0.25%
Secured Debt [Member] | Port Imperial 4/5 Hotel [Member]
Debt Instrument [Line Items]
Property Name						Port Imperial 4/5 Hotel
Lender						Fifth Third Bank & Santander
LIBOR						LIBOR+4.50
Effective rate						4.50%
Principal balance outstanding						$ 73,350,000	43,674,000
Loan maturity date						Oct. 6, 2019
Secured Debt [Member] | Port Imperial 4/5 Hotel [Member] | Construction Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 94,000,000
Number of extension options | item						2
Loan extension period						1 year
Extension fee						0.20%
Secured Debt [Member] | Worcester [Member]
Debt Instrument [Line Items]
Property Name						Worcester
Lender						Citizens Bank
LIBOR						LIBOR+2.50
Effective rate						2.50%
Principal balance outstanding						$ 56,892,000	37,821,000
Loan maturity date						Dec. 10, 2019
Secured Debt [Member] | Worcester [Member] | Construction Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 58,000,000
Number of extension options | item						2
Loan extension period						1 year
Extension fee						0.15%
Secured Debt [Member] | Monaco [Member]
Debt Instrument [Line Items]
Property Name						Monaco
Lender						The Northwestern Mutual Life Insurance Co.
Effective rate						3.15%
Principal balance outstanding						$ 168,370,000	169,987,000
Loan maturity date						Feb. 1, 2021
Adjustment for unamortized debt discount						$ 3,400,000
Secured Debt [Member] | 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%
Principal balance outstanding						$ 4,000,000	4,000,000
Loan maturity date						Dec. 1, 2021
Secured Debt [Member] | Portside 7 [Member]
Debt Instrument [Line Items]
Property Name						Portside 7
Lender						CBRE Capital Markets/FreddieMac
Effective rate						3.57%
Principal balance outstanding						$ 58,998,000	58,998,000
Loan maturity date						Aug. 1, 2023
Secured Debt [Member] | Alterra I & II [Member]
Debt Instrument [Line Items]
Property Name						Alterra I & II
Lender						Capital One/FreddieMac
Effective rate						3.85%
Principal balance outstanding						$ 100,000,000	100,000,000
Loan maturity date						Feb. 1, 2024
Secured Debt [Member] | The Chase At Overlook Ridge [Member]
Debt Instrument [Line Items]
Property Name						The Chase at Overlook Ridge
Lender						New York Community Bank
Effective rate						3.74%
Principal balance outstanding						$ 135,750,000	135,750,000
Loan maturity date						Jan. 1, 2025
Secured Debt [Member] | Portside 5/6 [Member]
Debt Instrument [Line Items]
Property Name						Portside 5/6
Lender						New York Life Insurance Company
Effective rate						4.56%
Principal balance outstanding						$ 97,000,000	45,778,000
Maximum borrowing capacity		$ 97,000,000
Unamortized deferred financing costs		200,000
Secured Debt [Member] | Portside 5/6 [Member] | Construction Loan [Member]
Debt Instrument [Line Items]
Payment for borrowings		$ 70,000,000
Secured Debt [Member] | Marbella I [Member]
Debt Instrument [Line Items]
Property Name						Marbella
Lender						New York Life Insurance Company
Effective rate						4.17%
Principal balance outstanding						$ 131,000,000
Loan maturity date						Aug. 10, 2026
Secured Debt [Member] | 101 Hudson [Member]
Debt Instrument [Line Items]
Property Name						101 Hudson
Lender						Wells Fargo CMBS
Effective rate						3.20%
Principal balance outstanding						$ 250,000,000	250,000,000
Loan maturity date						Oct. 11, 2026
Secured Debt [Member] | Short Hills Portfolio [Member]
Debt Instrument [Line Items]
Property Name						Short Hills Portfolio
Lender						Wells Fargo CMBS
Effective rate						4.15%
Principal balance outstanding						$ 124,500,000	124,500,000
Loan maturity date						Apr. 1, 2027
Secured Debt [Member] | 150 Main St [Member]
Debt Instrument [Line Items]
Property Name						150 Main St.
Lender						Natixis Real Estate Capital LLC
Effective rate						4.48%
Principal balance outstanding						$ 41,000,000	41,000,000
Loan maturity date						Aug. 5, 2027
Secured Debt [Member] | Port Imperial South 11 [Member]
Debt Instrument [Line Items]
Property Name						Port Imperial South 11
Lender						The Northwestern Mutual Life Insurance Co.
Effective rate						4.52%
Principal balance outstanding						$ 100,000,000	46,113,000
Loan maturity date						Jan. 10, 2029
Maximum borrowing capacity	$ 100,000,000
Unamortized deferred financing costs	300,000
Secured Debt [Member] | Port Imperial South 11 [Member] | Construction Loan [Member]
Debt Instrument [Line Items]
Payment for borrowings	$ 70,100,000
Secured Debt [Member] | Port Imperial 4/5 Garage Development [Member]
Debt Instrument [Line Items]
Property Name						Port Imperial South 4/5 Garage
Lender						American General Life & A/G PC
Effective rate						4.85%
Principal balance outstanding						$ 32,600,000	$ 32,600,000
Loan maturity date						Dec. 1, 2029

Mortgages, Loans Payable And _5

Mortgages, Loans Payable And Other Obligatons (Schedule Of Principal Payments) (Details)	Jan. 07, 2019USD ($)item	Dec. 31, 2018USD ($)
Mortgages, Loans Payabes And Other Obligations [Line Items]
Scheduled Amortization, 2019		$ 532,000
Scheduled Amortization, 2020		2,903,000
Scheduled Amortization, 2021		3,227,000
Scheduled Amortization, 2022		3,284,000
Scheduled Amortization, 2023		3,412,000
Scheduled Amortization, Thereafter		7,230,000
Scheduled Amortization, Sub-total		20,588,000
Adjustment for unamortized debt discount/premium, net December 31, 2018		(2,838,000)
Scheduled Amortization, Unamortized mark to market		3,370,000
Unamortized deferred financing costs		(11,907,000)
Scheduled Amortization, Total		9,213,000
Principal Maturities, 2019		546,711,000
Principal Maturities, 2020		325,000,000
Principal Maturities, 2021		285,800,000
Principal Maturities, 2022		300,000,000
Principal Maturities, 2023		333,998,000
Principal Maturities, Thereafter		991,929,000
Principal Maturities, Sub-total		2,783,438,000
Principal Maturities, Total		2,783,438,000
Total, 2019		547,243,000
Total, 2020		327,903,000
Total, 2021		289,027,000
Total, 2022		303,284,000
Total, 2023		337,410,000
Total, Thereafter		999,159,000
Total, Sub-total		2,804,026,000
Adjustment for unamortized debt discount/premium, net December 31, 2018		(2,838,000)
Total, Unamortized mark to market		3,370,000
Total, Unamortized deferred financing costs		(11,907,000)
Total senior unsecured notes, net		$ 2,792,651,000
Subsequent Event [Member] | 2016 Term Loan [Member]
Mortgages, Loans Payabes And Other Obligations [Line Items]
Mortgage payable amount	$ 350
Number of extensions exercised | item	1

Employee Benefit 401(k) Plans (

Employee Benefit 401(k) Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
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	$ 886,000	$ 1,055,000	$ 1,029,000
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

Disclosure Of Fair Value Of A_2

Disclosure Of Fair Value Of Assets And Liabilities (Narrative) (Details)	12 Months Ended
	Dec. 31, 2018USD ($)propertyitem	Dec. 31, 2017USD ($)property
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of Company's long-term debt	$ 2,711,712,000	$ 2,764,033,000
Principal balance outstanding	2,792,651,000	2,809,568,000
Aggregate carrying value	108,848,000	171,578,000
Land impairments	24,566,000
Office [Member] | Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unrealized losses on rental properties held for sale	20,100,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Parsippany, Paramus, Rochelle Park, Hamilton And Wall, New Jersey And White Plains, New York [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregate carrying value		$ 171,578,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregate carrying value	$ 108,848,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member] | Parsippany, Paramus, Rochelle Park, Hamilton And Wall, New Jersey And White Plains, New York [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Number of properties held for sale | property		21
Aggregate carrying value		$ 171,600,000
Estimated expected sales proceeds		$ 223,000,000
Number of properties not expected to recover from estimated net sales proceeds | property		7
Unrealized losses on rental properties held for sale		$ 12,300,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member] | Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Number of properties held for sale | property	6
Aggregate carrying value	$ 108,800,000
Estimated expected sales proceeds	$ 124,000,000
Number of properties not expected to recover from estimated net sales proceeds | property	4
Unrealized losses on rental properties held for sale	$ 20,100,000
Number of real estate properties | item	159
Disposal Group, Not Discontinued Operations [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unrealized losses on rental properties held for sale	$ (20,135,000)	$ (12,331,000)

Commitments And Contingencies_2

Commitments And Contingencies (Tax Abatement Agreements) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended			16 Months Ended	60 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 30, 2017	Apr. 30, 2022
Commitments And Contingencies [Line Items]
Percentage of PILOT on gross revenues	10.00%
Harborside Plaza 4-A [Member]
Commitments And Contingencies [Line Items]
Project period	20 years
Percentage of PILOT on project costs	2.00%
Total project costs	$ 49.5
Payments in lieu of property taxes (PILOT)	$ 1.1	$ 1.1	$ 1.1
Harborside Plaza 5 [Member]
Commitments And Contingencies [Line Items]
Project period	20 years
Percentage of PILOT on project costs	2.00%
Total project costs	$ 170.9
Payments in lieu of property taxes (PILOT)	$ 4.4	3.9	3.9
Port Imperial South 4/5 Garage [Member]
Commitments And Contingencies [Line Items]
Project period	5 years
Port Imperial South 4/5 Garage [Member] | Tax Year 1 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	0.00%
Port Imperial South 4/5 Garage [Member] | Tax Year 2 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	80.00%
Port Imperial South 4/5 Garage [Member] | Tax Year 3 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	80.00%
Port Imperial South 4/5 Garage [Member] | Tax Year 4 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	80.00%
Port Imperial South 4/5 Garage [Member] | Tax Year 5 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	80.00%
Port Imperial South 1/3 Garage [Member]
Commitments And Contingencies [Line Items]
Project period	5 years
Percentage of taxes paid based on the land value	100.00%
Port Imperial South 1/3 Garage [Member] | Tax Year 1 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	0.00%
Port Imperial South 1/3 Garage [Member] | Tax Year 2 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	95.00%
Port Imperial South 1/3 Garage [Member] | Tax Year 3 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	95.00%
Port Imperial South 1/3 Garage [Member] | Tax Year 4 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	95.00%
Port Imperial South 1/3 Garage [Member] | Tax Year 5 [Member]
Commitments And Contingencies [Line Items]
Annual percentage of cost for phase in	95.00%
Port Imperial Hotel Development [Member]
Commitments And Contingencies [Line Items]
Project period	15 years
Percentage of PILOT on project costs	2.00%
Port Imperial South 11 Development [Member]
Commitments And Contingencies [Line Items]
Project period	15 years
Percentage of PILOT on gross revenues	10.00%
111 River Realty [Member]
Commitments And Contingencies [Line Items]
Payments in lieu of property taxes (PILOT)	$ 1.4	1.3	$ 0.6
Annual Payments in lieu of property taxes (PILOT)				$ 1.2
111 River Realty [Member] | Scenario, Forecast [Member]
Commitments And Contingencies [Line Items]
Annual Payments in lieu of property taxes (PILOT)					$ 1.4
Monaco [Member]
Commitments And Contingencies [Line Items]
Project period	10 years
Payments in lieu of property taxes (PILOT)	$ 2.4	$ 1.6
Marbella Tower Urban Renewal Associates LLC [Member]
Commitments And Contingencies [Line Items]
Percentage of PILOT on project costs	15.00%
Payments in lieu of property taxes (PILOT)	$ 0.9
Marbella II [Member]
Commitments And Contingencies [Line Items]
Project period	10 years
Marbella II [Member] | Years 1-4 [Member]
Commitments And Contingencies [Line Items]
Percentage of PILOT on gross revenues	10.00%
Marbella II [Member] | Years 5-8 [Member]
Commitments And Contingencies [Line Items]
Percentage of PILOT on gross revenues	12.00%
Marbella II [Member] | Years 9-10 [Member]
Commitments And Contingencies [Line Items]
Percentage of PILOT on gross revenues	14.00%
Port Imperial South Parcel 8/9 [Member]
Commitments And Contingencies [Line Items]
Project period	25 years
Port Imperial South Parcel 8/9 [Member] | Years 1-10 [Member]
Commitments And Contingencies [Line Items]
Percentage of PILOT on gross revenues	11.00%
Port Imperial South Parcel 8/9 [Member] | Years 11-18 [Member]
Commitments And Contingencies [Line Items]
Percentage of PILOT on gross revenues	12.50%
Port Imperial South Parcel 8/9 [Member] | Years 19-25 [Member]
Commitments And Contingencies [Line Items]
Percentage of PILOT on gross revenues	14.00%

Commitments And Contingencies_3

Commitments And Contingencies (Ground Lease Agreements) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments And Contingencies [Abstract]
Ground lease expense incurred	$ 2.3	$ 2.6	$ 1.5

Commitments And Contingencies_4

Commitments And Contingencies (Construction Projects) (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)item	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015item
Commitments And Contingencies [Line Items]
Costs of the project incurred	$ 39,054	$ 42,598	$ 49,624
Number of units | item	1,317
Amount outstanding	$ 790,939	$ 822,288
XS Hotel Urban Renewal Associates LLC [Member]
Commitments And Contingencies [Line Items]
Percentage of interest in venture				90.00%
Development costs	147,100
Number of units | item				372
Total project costs	$ 159,900
XS Hotel Urban Renewal Associates LLC, Residence Inn [Member]
Commitments And Contingencies [Line Items]
Number of units | item				164
XS Hotel Urban Renewal Associates LLC, Marriott Envue [Member]
Commitments And Contingencies [Line Items]
Number of units | item				208
Portside 5/6 [Member]
Commitments And Contingencies [Line Items]
Number of units | item	296
Chase III, Overlook Ridge [Member]
Commitments And Contingencies [Line Items]
Costs of the project incurred	$ 20,200
Delivery date to tenant	fourth quarter 2020
Number of units | item	326
Amount to fund	$ 37,900
Building 89 [Member]
Commitments And Contingencies [Line Items]
Costs of the project incurred	$ 35,400
Delivery date to tenant	fourth quarter 2020
Number of units | item	313
Total project costs	$ 142,600
Amount to fund	50,600
Construction Loan [Member] | XS Hotel Urban Renewal Associates LLC [Member]
Commitments And Contingencies [Line Items]
Maximum borrowing capacity	94,000
Amount outstanding	73,400
Construction Loan [Member] | Chase III, Overlook Ridge [Member]
Commitments And Contingencies [Line Items]
Total project costs	99,900
Amount to fund	62,000
Construction Loan [Member] | Building 89 [Member]
Commitments And Contingencies [Line Items]
Development costs	35,400
Amount outstanding	$ 92,000

Commitments And Contingencies_5

Commitments And Contingencies (Changes In Executive Officers) (Narrative) (Details) - USD ($)	Jun. 05, 2018	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments And Contingencies [Line Items]
Payment to former executive officers			$ 1,200,000
General and administrative			53,988,000	$ 50,949,000	$ 51,979,000
Accounts payable, accrued expenses and other liabilities			168,115,000	$ 192,716,000
Restructuring costs related to stock compensation			$ 1,000,000
Shares granted			40,185	59,985	74,622
Common stock trading days			30 days
Mack-Cali Realty LP [Member]
Commitments And Contingencies [Line Items]
General and administrative			$ 53,988,000	$ 50,949,000	$ 51,979,000
Accounts payable, accrued expenses and other liabilities			$ 168,115,000	$ 192,716,000
Messr Rudin [Member]
Commitments And Contingencies [Line Items]
Severance benefits		$ 2,558,082
Period for continuation of health insurance			18 months
Payment of unreimbursed expenses		50,000
COBRA payment		$ 34,047
Accounts payable, accrued expenses and other liabilities			$ 23,000
Restructuring costs related to stock compensation			1,600,000
Messr Krug [Member]
Commitments And Contingencies [Line Items]
Severance benefits			1,312,500
Prorated 2018 target bonus amount			$ 93,750
Messr Krug [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Period for continuation of health insurance			2 years
COBRA payment			$ 42,000
Messr DeLorenzo [Member]
Commitments And Contingencies [Line Items]
Severance benefits			$ 500,000
Messr DeLorenzo [Member] | Mack-Cali Realty LP [Member]
Commitments And Contingencies [Line Items]
Partial accelerated vesting shares			9,111
Messr DeLorenzo [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Period for continuation of health insurance			18 months
COBRA payment			$ 42,000
Messr Krug And Messr DeLorenzo [Member] | Employee Severance [Member]
Commitments And Contingencies [Line Items]
General and administrative			2,700,000
Accounts payable, accrued expenses and other liabilities			43,000
Robert Andrew Marshall [Member]
Commitments And Contingencies [Line Items]
Consulting payment			22,500
Payment to former executive officers			100,000
COBRA payment			7,533
Accounts payable, accrued expenses and other liabilities			1,000,000
Restructuring costs related to stock compensation			$ 300,000
Time-Based Award [Member] | Messr Rudin [Member] | Mack-Cali Realty LP [Member]
Commitments And Contingencies [Line Items]
Shares granted	32,311
Time-Based Award [Member] | Messr Krug [Member] | Mack-Cali Realty LP [Member]
Commitments And Contingencies [Line Items]
Accelerated vesting shares			13,306
Performance Shares [Member] | Messr Rudin [Member] | Mack-Cali Realty LP [Member]
Commitments And Contingencies [Line Items]
Shares granted	175,127
Performance Shares [Member] | Messr Krug [Member] | Mack-Cali Realty LP [Member]
Commitments And Contingencies [Line Items]
Accelerated vesting shares			18,665
Performance Shares [Member] | Messr DeLorenzo [Member] | Mack-Cali Realty LP [Member]
Commitments And Contingencies [Line Items]
Partial accelerated vesting shares			13,982
Vested 2016 Time-Based LTIP Awards [Member] | Robert Andrew Marshall [Member]
Commitments And Contingencies [Line Items]
Shares granted			22,120
Vested 2016 Performance-Based LTIP Awards [Member] | Robert Andrew Marshall [Member]
Commitments And Contingencies [Line Items]
Shares granted			28,880
Vested 2016 LTIP Awards [Member] | Robert Andrew Marshall [Member]
Commitments And Contingencies [Line Items]
Shares granted			35,697
Shares to repurchase			51,000
Common stock trading days			5 days
Performance-Based LTIP Award Issued March 2016 [Member] | Robert Andrew Marshall [Member]
Commitments And Contingencies [Line Items]
Shares expired, forfeited or cancelled			6,817
Time-Based LTIP Award Issued April 2017 [Member] | Robert Andrew Marshall [Member]
Commitments And Contingencies [Line Items]
Shares expired, forfeited or cancelled			4,449
Performance-Based LTIP Award Issued April 2017 [Member] | Robert Andrew Marshall [Member]
Commitments And Contingencies [Line Items]
Shares expired, forfeited or cancelled			13,473
Time-Based LTIP Award Issued April 2018 [Member] | Robert Andrew Marshall [Member]
Commitments And Contingencies [Line Items]
Shares expired, forfeited or cancelled			11,799
Performance-Based LTIP Award Issued April 2018 [Member] | Robert Andrew Marshall [Member]
Commitments And Contingencies [Line Items]
Shares expired, forfeited or cancelled			22,676

Commitments And Contingencies_6

Commitments And Contingencies (Other) (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)property	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Aug. 31, 2017USD ($)
Commitments And Contingencies [Line Items]
Purchase price of property	$ 168,398	$ 90,068	$ 121,582
Notes Receivable 5.85 Interest Rate [Member]
Commitments And Contingencies [Line Items]
Notes receivable	$ 45,200			$ 44,700
Interest rate	5.85%
Purchase price of property	$ 73,000
Prepayment of note receivable	$ 3,000
Property Lock-Ups Expired [Member]
Commitments And Contingencies [Line Items]
Number of properties | property	79
Properties aggregate net book value	$ 1,400,000

Commitments And Contingencies_7

Commitments And Contingencies (Future Minimum Rental Payments Of Ground Leases) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Commitments And Contingencies [Abstract]
2,019	$ 2,470
2,020	2,491
2,021	2,491
2,022	2,491
2,023	2,491
2024 through 2084	210,117
Total	$ 222,551

Tenant Leases (Future Minimum R

Tenant Leases (Future Minimum Rentals To Be Received Under Non-Cancelable Operating Leases) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Property Subject to or Available for Operating Lease [Line Items]
2,019	$ 314,708
2,020	306,559
2,021	284,120
2,022	258,076
2,023	220,533
2024 and thereafter	923,061
Total	$ 2,307,057
Tenant Leases [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating leases with various expiration dates through year	Dec. 31, 2036
Multi-Family Properties [Member]
Property Subject to or Available for Operating Lease [Line Items]
Lease period	1 year

Redeemable Noncontrolling Int_3

Redeemable Noncontrolling Interests (Narrative) (Details) - USD ($)	Mar. 10, 2017	Feb. 28, 2017	Feb. 27, 2017	Feb. 03, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 30, 2017
Redeemable Noncontrolling Interest [Line Items]
Expiration period					10 years
Minimum [Member]
Redeemable Noncontrolling Interest [Line Items]
Percentage of interest in venture					20.00%
Maximum [Member]
Redeemable Noncontrolling Interest [Line Items]
Percentage of interest in venture					85.00%
Mack-Cali Realty LP [Member]
Redeemable Noncontrolling Interest [Line Items]
Common unit distribution per unit declared					$ 0.80	$ 0.75	$ 0.60
Rockpoint [Member]
Redeemable Noncontrolling Interest [Line Items]
Pro rata distribution					17.10%
Estimated redemption value					$ 330,000,000
Invested capital					$ 255,000,000
RRT [Member]
Redeemable Noncontrolling Interest [Line Items]
Pro rata distribution					82.90%
Series A Units [Member] | Mack-Cali Realty LP [Member]
Redeemable Noncontrolling Interest [Line Items]
Preferred stock shares issued				42,800
Preferred units shares issued				42,800
Preferred unit annual rate				3.50%
Percentage of interest in venture				37.50%
Preferred unit in operating partnership				$ 1,000
Convertible preferred units				28.15
Expiration period				5 years
Shares converted to common units				1,204,820
Common unit distribution per unit declared				$ 35.52
Series A-1 Units [Member] | Mack-Cali Realty LP [Member]
Redeemable Noncontrolling Interest [Line Items]
Preferred stock shares issued		9,213
Preferred units shares issued		9,213						91
Preferred unit annual rate		3.50%
Percentage of interest in venture		13.80%
Preferred unit in operating partnership		$ 1,000
Convertible preferred units		27.936
Expiration period		5 years
Shares converted to common units		257,375
Common unit distribution per unit declared		$ 35.80
Monaco [Member] | Series A-1 Units [Member]
Redeemable Noncontrolling Interest [Line Items]
Percentage of interest in venture		29.00%	13.80%
Monaco [Member] | Series A-1 Units [Member] | Mack-Cali Realty LP [Member]
Redeemable Noncontrolling Interest [Line Items]
Preferred units shares issued		9,122						91
Percentage of interest in venture								71.20%
Investment Agreement [Member] | Rockpoint [Member]
Redeemable Noncontrolling Interest [Line Items]
Contributed equity value	$ 1,230,000,000
Incremental closing payments, Limited Partnership interest	$ 150,000,000				$ 105,000,000
Investment Agreement [Member] | Rockpoint [Member] | Minimum [Member]
Redeemable Noncontrolling Interest [Line Items]
Incremental closing payments, Limited Partnership interest					$ 10,000,000
Investment Agreement [Member] | Rockpoint [Member] | Maximum [Member]
Redeemable Noncontrolling Interest [Line Items]
Contributed amount to obtain equity units			$ 300,000,000
RRLP [Member]
Redeemable Noncontrolling Interest [Line Items]
Annual return on the equity value					6.00%
RRLP [Member] | Rockpoint [Member]
Redeemable Noncontrolling Interest [Line Items]
Annual return					6.00%
Base return					5.00%
Internal rate of return					11.00%
Pro rata share					50.00%
RRLP [Member] | RRT [Member]
Redeemable Noncontrolling Interest [Line Items]
Base return					95.00%
Participation Rights [Member] | Maximum [Member]
Redeemable Noncontrolling Interest [Line Items]
Contributed amount to obtain equity units					$ 200,000,000

Redeemable Noncontrolling Int_4

Redeemable Noncontrolling Interests (Schedule Of Changes In The Value Of The Redeemable Noncontrolling Interests) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Redeemable Noncontrolling Interest [Line Items]
Balance January 1, 2018	$ 212,208
Income Attributed to Noncontrolling Interests	(13,979)	$ (8,840)
Redemption Value Adjustment	(26,700)	(28,865)
Redeemable noncontrolling interests as of December 31, 2018	330,459	212,208
Redeemable Noncontrolling Interests [Member]
Redeemable Noncontrolling Interest [Line Items]
Balance January 1, 2018	212,208
Redeemable Noncontrolling Interests Issued	105,000
Net	317,208
Income Attributed to Noncontrolling Interests	13,979
Distributions	(13,979)
Redemption Value Adjustment	13,251
Redeemable noncontrolling interests as of December 31, 2018	330,459	212,208
Redeemable Noncontrolling Interests [Member] | Series A And Series A-1 Preferred Units [Member]
Redeemable Noncontrolling Interest [Line Items]
Balance January 1, 2018	52,324
Net	52,324
Income Attributed to Noncontrolling Interests	1,820
Distributions	(1,820)
Redeemable noncontrolling interests as of December 31, 2018	52,324	52,324
Redeemable Noncontrolling Interests [Member] | Rockpoint [Member]
Redeemable Noncontrolling Interest [Line Items]
Balance January 1, 2018	159,884
Redeemable Noncontrolling Interests Issued	105,000
Net	264,884
Income Attributed to Noncontrolling Interests	12,159
Distributions	(12,159)
Redemption Value Adjustment	13,251
Redeemable noncontrolling interests as of December 31, 2018	$ 278,135	$ 159,884

Mack-Cali Realty Corporation _3

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Share/Unit Repurchase Program And Dividend Reinvestment And Stock Purchase Plan) (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2012
Stockolders Equity [Line Items]
Date share repurchase program was initiated	September 2,012
Capacity of share repurchase program	$ 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
Proceeds from sale of common units		$ 11,000,000
Dividend Reinvestment And Stock Purchase Plan [Member]
Stockolders Equity [Line Items]
Common stock reserved for future issuance	5,500,000
Monthly cash investment without restriction, maximum	$ 5,000

Mack-Cali Realty Corporation _4

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Stock Option Plans) (Narrative) (Details)	Jun. 05, 2015item$ / sharesshares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	May 31, 2013shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual life		6 years 4 months 24 days	7 years 4 months 24 days
Share price | $ / shares	$ 17.31
Proceeds from stock options exercised | $		$ 0	$ 0	$ 0
Stock options expense | $		$ 193,000	$ 464,000	$ 1,407,000
Shares Under Options - Granted	800,000
Common stock trade share price | $ / shares	$ 25
Annual installments | item	3
Exercisable period		10 years
Common stock trading days		30 days
Three Equal Annual Installment [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Under Options - Granted	400,000
Common Stock Trades [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Under Options - Granted	400,000
2013 Incentive Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved stocks for issuance					4,600,000

Mack-Cali Realty Corporation _5

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Restricted Stock Awards And Performance Share Units) (Narrative) (Details) - USD ($)	Jun. 05, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested stock outstanding		67,289	108,318	145,278	136,220
Shares granted		40,185	59,985	74,622
Restricted Stock [Member] | 2013 Incentive Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation vesting period		3 years
Shares granted	37,550.54
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
Unvested Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested stock outstanding		67,289	95,801	120,245
Total Stockholder Return Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost		$ 500,000
Total unrecognized compensation cost, period of recognition		6 months
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested stock outstanding		0
Total unrecognized compensation cost		$ 0
Performance Shares [Member] | 2013 Incentive Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	112,651.64
Performance period		3 years
Performance Shares [Member] | Minimum [Member] | 2013 Incentive Stock Plan [Member] | Three Years Period Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vested	0.00%
Performance Shares [Member] | Maximum [Member] | 2013 Incentive Stock Plan [Member] | Three Years Period Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vested	150.00%

Mack-Cali Realty Corporation _6

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Long-Term Incentive Plan Awards) (Narrative) (Details) - USD ($)	Apr. 20, 2018	Apr. 04, 2017	Mar. 08, 2016	Jun. 05, 2015	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				800,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost					$ 0
2016 LTIP Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends paid, percent representing common unit of limited partnership interest					10.00%
Dividends paid, percent payable upon vesting of LTIP Unit					90.00%
Shares granted					22,215
Total unrecognized compensation cost					$ 11,200,000
Total unrecognized compensation cost, period of recognition					2 years 4 months 24 days
Shares forfeited and cancelled					189,273
2016 TBV LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted					108,764
2016 OPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period					3 years
TSR percent					50.00%
2016 OPP [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period					3 years
2016 PBV LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted					332,302
2017 LTIP Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted					32,849
Shares forfeited and cancelled					105,443
2017 OPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period					3 years
TSR percent					36.00%
2017 PBV LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted					370,509
2017 TBV LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted					69,522
2018 LTIP Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares forfeited and cancelled					38,015
2018 OPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period					3 years
TSR percent					36.00%
2018 PBV LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted					629,252
2018 TBV LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted					196,757
Messieur Rudin, Messieur DeMarco, And Messieur Tycher [Member] | 2016 LTIP Awards [Member] | Time-Based Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of the award			25.00%
Performance period					3 years
Messieur Rudin, Messieur DeMarco, And Messieur Tycher [Member] | 2016 LTIP Awards [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining percent of the award			75.00%
Messieur Rudin, Messieur DeMarco, And Messieur Tycher [Member] | 2017 LTIP Awards [Member] | Time-Based Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of the award		25.00%
Messieur Rudin, Messieur DeMarco, And Messieur Tycher [Member] | 2017 LTIP Awards [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining percent of the award		75.00%
Messieur Rudin, Messieur DeMarco, And Messieur Tycher [Member] | 2017 TBV LTIP Units [Member] | Time-Based Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period					3 years
Other Executive Officers [Member] | 2016 LTIP Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of the award			40.00%
Remaining percent of the award			60.00%
Other Executive Officers [Member] | 2017 LTIP Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of the award		40.00%
Remaining percent of the award		60.00%
Other Executive Officers [Member] | 2018 LTIP Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of the award	50.00%
Remaining percent of the award	50.00%
Messieur DeMarco And Messieur Tycher [Member] | 2018 LTIP Awards [Member] | Time-Based Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of the award	25.00%
Performance period					3 years
Messieur DeMarco And Messieur Tycher [Member] | 2018 LTIP Awards [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining percent of the award	75.00%

Mack-Cali Realty Corporation _7

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Deferred Stock Compensation Plan For Directors) (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital [Abstract]
Maximum percentage of retainer fee that directors may defer	100.00%
Deferred stock units earned	26,620	19,728	14,274
Deferred stock units outstanding	236,383	210,738

Mack-Cali Realty Corporation _8

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Earnings Per Share/Unit) (Narrative) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested stock outstanding	67,289	108,318	145,278	136,220
Dividends declared per common share	$ 0.80	$ 0.75	$ 0.60
Mack-Cali Realty LP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Distribution declared per common unit	$ 0.80	$ 0.75	$ 0.60
Unvested Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested stock outstanding	67,289	95,801	120,245
Unvested Restricted Stock [Member] | Mack-Cali Realty LP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested stock outstanding	67,289	95,801	120,245

Mack-Cali Realty Corporation _9

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Schedule Of Stock Option Plans) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding stock option price	$ 17.31	$ 17.31	$ 17.31
2013 Incentive Stock Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares Under Options - Outstanding, beginning balance	800,000	800,000	805,000
Shares Under Options - Granted, Lapsed or Cancelled
Shares Under Options - Lapsed or Cancelled			(5,000)
Shares Under Options - Outstanding, ending balance	800,000	800,000	800,000
Shares Under Options - Options exercisable	800,000
Shares Under Options - Available for grant	1,580,869
Weighted Average Exercise Price - Outstanding, beginning balance	$ 17.31	$ 17.31	$ 17.33
Weighted Average Exercise Price - Granted, Lapsed or Cancelled
Weighted Average Exercise Price - Lapsed or Cancelled			21.25
Weighted Average Exercise Price - Outstanding, ending balance	$ 17.31	$ 17.31	$ 17.31
Aggregate Intrinsic Value, Outstanding, beginning balance	$ 3,400	$ 9,368	$ 4,843
Aggregate Intrinsic Value, Outstanding, ending balance	$ 1,824	$ 3,400	$ 9,368

Mack-Cali Realty Corporation_10

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Schedule Of Restricted Stock Awards) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital [Abstract]
Shares, Outstanding, Beginning balance	108,318	145,278	136,220
Shares, Granted	40,185	59,985	74,622
Shares, Vested	(72,502)	(95,009)	(61,654)
Shares, Cancelled	(8,712)	(1,936)	(3,910)
Shares, Outstanding, Ending balance	67,289	108,318	145,278
Weighted-Average Grant-Date Fair Value, Outstanding beginning balance	$ 25.49	$ 21.76	$ 19.36
Weighted-Average Grant-Date Fair Value, Granted	20.16	27	23.79
Weighted-Average Grant-Date Fair Value, Vested	25.33	20.73	18.94
Weighted-Average Grant-Date Fair Value, Cancelled	25.83	25.83	21.58
Weighted-Average Grant-Date Fair Value, Outstanding ending balance	$ 22.43	$ 25.49	$ 21.76

Mack-Cali Realty Corporation_11

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Earnings Per Share Tables - Basic Computation Of EPS) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stockolders Equity [Line Items]
Net income									$ 106,401	$ 33,718	$ 130,294
Add: Noncontrolling interest in consolidated joint ventures									1,216	1,018	651
Add (deduct): Noncontrolling interest in Operating Partnership									(9,527)	(2,711)	(13,721)
Deduct: Redeemable noncontrolling interest									(13,979)	(8,840)
Deduct: Redemption value adjustment of redeemable noncontrolling interests attributable to common shareholders									(11,425)	(17,951)
Net income available to common shareholders for basic earnings per share									$ 72,686	$ 5,234	$ 117,224
Weighted average common shares									90,388	90,005	89,746
Net income available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.31
Mack-Cali Realty LP [Member]
Stockolders Equity [Line Items]
Net income									$ 106,401	$ 33,718	$ 130,294
Add: Noncontrolling interest in consolidated joint ventures									1,216	1,018	651
Deduct: Redeemable noncontrolling interest									(13,979)	(8,840)
Deduct: Redemption value adjustment of redeemable noncontrolling interests attributable to common shareholders									(12,721)	(20,025)
Net income available to common shareholders for basic earnings per share									$ 80,917	$ 5,871	$ 130,945
Weighted average common units									100,634	100,410	100,245
Net income available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.31

Mack-Cali Realty Corporation_12

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Earnings Per Share Tables - Diluted Computation Of EPS) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stockolders Equity [Line Items]
Net income available to common shareholders for basic earnings per share									$ 72,686	$ 5,234	$ 117,224
Add (deduct): Noncontrolling interest in Operating Partnership									9,527	2,711	13,721
Deduct: Redeemable noncontrolling interest									(13,979)	(8,840)
Deduct: Redemption value adjustment of redeemable noncontrolling interests in Operating Partnership unitholders									(1,296)	(2,074)
Net income available for diluted earnings per share									$ 80,917	$ 5,871	$ 130,945
Weighted average common shares									100,724	100,703	100,498
Net income available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.30
Mack-Cali Realty LP [Member]
Stockolders Equity [Line Items]
Net income available to common shareholders for basic earnings per share									$ 80,917	$ 5,871	$ 130,945
Deduct: Redeemable noncontrolling interest									$ (13,979)	$ (8,840)
Weighted average common unit									100,724	100,703	100,498
Net income available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.30

Mack-Cali Realty Corporation_13

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Schedule Of Reconciliation Of Shares Used In Basic EPS Calculation To Shares Used In Diluted EPS Calculation) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stockolders Equity [Line Items]
Basic EPS shares	90,388	90,005	89,746
Add: Operating Partnership - common and vested LTIP Units	10,246	10,405	10,499
Restricted Stock Awards		40	43
Stock Options	90	253	210
Diluted EPS Shares	100,724	100,703	100,498
Mack-Cali Realty LP [Member]
Stockolders Equity [Line Items]
Basic EPS units	100,634	100,410	100,245
Restricted Stock Awards		40	43
Stock Options	90	253	210
Diluted EPU Units	100,724	100,703	100,498

Noncontrolling Interests In S_3

Noncontrolling Interests In Subsidiaries (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)propertyshares	Dec. 31, 2017
Noncontrolling Interest [Line Items]
Number of common shares received upon redemption of common units | shares	1
Rebalance of ownership percentage | $	$ 2.2
Percentage of noncontrolling interest	10.20%	10.40%
Participation Rights [Member]
Noncontrolling Interest [Line Items]
Number of properties	2
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 S_4

Noncontrolling Interests In Subsidiaries (Changes In Noncontrolling Interests Of Subsidiaries) (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Noncontrolling Interests In Subsidiaries [Abstract]
Balance, Beginning, Common Units	10,438,855	10,488,105	10,516,844
Redemption of common units for shares of common stock	(264,570)	(148,662)	(28,739)
Issuance of units, Common Units		99,412
Balance, Ending, Common Units	10,174,285	10,438,855	10,488,105
Balance, Beginning, LTIP Units	1,230,877	657,373
Issuance of units, LTIP Units	864,024	578,323	657,373
Cancellation of units	(332,731)	(4,819)
Balance, Ending, LTIP Units	1,762,170	1,230,877	657,373

Segment Reporting (Narrative) (

Segment Reporting (Narrative) (Details)	3 Months Ended								12 Months Ended
	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of business segments | segment									2
Total revenues	$ 132,936,000	$ 132,114,000	$ 126,589,000	$ 138,967,000	$ 143,529,000	$ 160,018,000	$ 162,766,000	$ 149,887,000	$ 530,606,000	$ 616,200,000	$ 613,398,000
Foreign Locations [Member]
Segment Reporting Information [Line Items]
Total revenues									0	0	$ 0
Long lived assets	$ 0				$ 0				$ 0	$ 0

Segment Reporting (Schedule Of

Segment Reporting (Schedule Of Selected Results Of Operations And Asset Information) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total revenues	$ 132,936	$ 132,114	$ 126,589	$ 138,967	$ 143,529	$ 160,018	$ 162,766	$ 149,887	$ 530,606	$ 616,200	$ 613,398
Total operating and interest expenses									358,507	396,306	415,351
Equity in earnings (loss) of unconsolidated joint ventures									(127)	(6,081)	18,788
Net operating income (loss)									171,972	213,813	216,835
Total assets	5,060,644				4,957,885				5,060,644	4,957,885
Total long-lived assets	4,420,679				4,291,126				4,420,679	4,291,126
Total investments in unconsolidated joint ventures	232,750				252,626				232,750	252,626
Commercial And Other Real Estate [Member]
Segment Reporting Information [Line Items]
Total revenues									416,369	522,223	541,271
Total operating and interest expenses									183,439	238,055	263,663
Equity in earnings (loss) of unconsolidated joint ventures									2,319	1,644	23,796
Net operating income (loss)									235,249	285,812	301,404
Total assets	2,687,178				2,915,646				2,687,178	2,915,646
Total long-lived assets	2,413,696				2,613,815				2,413,696	2,613,815
Total investments in unconsolidated joint ventures	13,699				15,143				13,699	15,143
Multiple-Family Real Estate & Services [Member]
Segment Reporting Information [Line Items]
Total revenues									113,805	90,654	69,873
Total operating and interest expenses									70,280	63,589	60,646
Equity in earnings (loss) of unconsolidated joint ventures									(2,446)	(7,725)	(5,008)
Net operating income (loss)									41,079	19,340	4,219
Total assets	2,260,497				1,937,708				2,260,497	1,937,708
Total long-lived assets	1,973,826				1,645,410				1,973,826	1,645,410
Total investments in unconsolidated joint ventures	218,771				237,321				218,771	237,321
Corporate & Other [Member]
Segment Reporting Information [Line Items]
Total revenues									432	3,323	2,254
Total operating and interest expenses									104,788	94,662	91,042
Net operating income (loss)									(104,356)	(91,339)	$ (88,788)
Total assets	112,969				104,531				112,969	104,531
Total long-lived assets	33,157				31,901				33,157	31,901
Total investments in unconsolidated joint ventures	$ 280				$ 162				$ 280	$ 162

Segment Reporting (Schedule O_2

Segment Reporting (Schedule Of Reconciliation Of Net Operating Income To Net Income Available To Common Shareholders) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net operating income									$ 171,972	$ 213,813	$ 216,835
Depreciation and amortization									(174,847)	(205,169)	(186,684)
Land Impairments									(24,566)
Gain on change of control of interests									14,217		15,347
Realized gains (losses) and unrealized losses on disposition of rental property, net									99,436	2,364	109,666
Gain on disposition of developable land									30,939
Gain on sale of investment in unconsolidated joint venture										23,131	5,670
Loss from extinguishment of debt, net									(10,750)	(421)	(30,540)
Net income	$ 52,523	$ 1,689	$ 1,501	$ 50,688	$ 5,411	$ 44,703	$ (39,125)	$ 22,729	106,401	33,718	130,294
Noncontrolling interest in consolidated joint ventures									1,216	1,018	651
Noncontrolling interest in Operating Partnership									(9,527)	(2,711)	(13,721)
Redeemable noncontrolling interest									(13,979)	(8,840)
Net income available to common shareholders	43,804	(1,478)	(1,251)	43,036	2,582	38,054	(37,330)	19,879	84,111	23,185	117,224
Mack-Cali Realty LP [Member]
Segment Reporting Information [Line Items]
Net operating income									171,972	213,813	216,835
Depreciation and amortization									(174,847)	(205,169)	(186,684)
Land Impairments									(24,566)
Gain on change of control of interests									14,217		15,347
Realized gains (losses) and unrealized losses on disposition of rental property, net									99,436	2,364	109,666
Gain on disposition of developable land									30,939
Gain on sale of investment in unconsolidated joint venture										23,131	5,670
Loss from extinguishment of debt, net									(10,750)	(421)	(30,540)
Net income	52,523	1,689	1,501	50,688	5,411	44,703	(39,125)	22,729	106,401	33,718	130,294
Noncontrolling interest in consolidated joint ventures									1,216	1,018	651
Redeemable noncontrolling interest									(13,979)	(8,840)
Net income available to common shareholders	$ 48,757	$ (1,645)	$ (1,393)	$ 47,919	$ 2,881	$ 42,467	$ (41,626)	$ 22,174	$ 93,638	$ 25,896	$ 130,945

Related Party Transactions (Det

Related Party Transactions (Details)	12 Months Ended
	Dec. 31, 2018USD ($)ft²property	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Mack [Member]
Related Party Transaction [Line Items]
Due from related parties	$ 0	$ 0
Marshall [Member]
Related Party Transaction [Line Items]
Due to Related Parties, Current	148,000
Accounts Payable, Related Parties, Current	0
RG [Member]
Related Party Transaction [Line Items]
Related party revenue	$ 1,114,000	1,873,000	$ 2,464,000
Leased Property [Member]
Related Party Transaction [Line Items]
Number of real estate properties | property	1
Lease expiration date	September 2,019
Leased Property [Member] | Mack [Member]
Related Party Transaction [Line Items]
Area Of Real Estate Property | ft²	7,034
Lease revenue	$ 193,000	$ 187,000	$ 193,000

Condensed Quarterly Financial_3

Condensed Quarterly Financial Information (Summary Of Condensed Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Quarterly Financial Information [Abstract]
Total revenues	$ 132,936	$ 132,114	$ 126,589	$ 138,967	$ 143,529	$ 160,018	$ 162,766	$ 149,887	$ 530,606	$ 616,200	$ 613,398
Net income (loss)	52,523	1,689	1,501	50,688	5,411	44,703	(39,125)	22,729	106,401	33,718	130,294
Net income (loss) available to common shareholders	$ 43,804	$ (1,478)	$ (1,251)	$ 43,036	$ 2,582	$ 38,054	$ (37,330)	$ 19,879	$ 84,111	$ 23,185	$ 117,224
Basic earnings per common share:
Net income available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.31
Diluted earnings per common share:
Net income (loss) available to common shareholders	$ 0.45	$ (0.05)	$ (0.05)	$ 0.45	$ (0.01)	$ 0.39	$ (0.44)	$ 0.11	$ 0.80	$ 0.06	$ 1.30

Real Estate Investments And A_2

Real Estate Investments And Accumulated Depreciation (Schedule Of Real Estate Investments And Accumulated Depreciation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Related Encumbrances	$ 1,406,239
Initial Costs, Land	788,528
Initial Costs, Building and Improvements	3,429,551
Costs Capitalized Subsequent to Acquisition	811,324
Gross Amount at Which Carried at Close of Period, Land	807,236
Gross Amount at Which Carried at Close of Period, Building and Improvements	4,498,781
Total	5,306,017	$ 5,102,844	$ 4,804,867	$ 4,807,718
Accumulated Depreciation	1,097,868	$ 1,087,083	$ 1,332,073	$ 1,464,482
Real Estate Aggregate Cost, Tax Purpose	$ 5,100,000
Office [Member] | One Bridge Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,981
Acquired	1,996
Initial Costs, Land	$ 2,439
Initial Costs, Building and Improvements	24,462
Costs Capitalized Subsequent to Acquisition	7,436
Gross Amount at Which Carried at Close of Period, Land	2,439
Gross Amount at Which Carried at Close of Period, Building and Improvements	31,898
Total	34,337
Accumulated Depreciation	$ 17,658
Office [Member] | 150 J.F. Kennedy Parkway [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,980
Acquired	1,997
Initial Costs, Land	$ 12,606
Initial Costs, Building and Improvements	50,425
Costs Capitalized Subsequent to Acquisition	17,073
Gross Amount at Which Carried at Close of Period, Land	12,606
Gross Amount at Which Carried at Close of Period, Building and Improvements	67,498
Total	80,104
Accumulated Depreciation	$ 33,259
Office [Member] | 51 J.F. Kennedy Parkway [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,988
Acquired	2,017
Related Encumbrances	$ 69,459
Initial Costs, Land	5,873
Initial Costs, Building and Improvements	100,359
Costs Capitalized Subsequent to Acquisition	575
Gross Amount at Which Carried at Close of Period, Land	5,873
Gross Amount at Which Carried at Close of Period, Building and Improvements	100,934
Total	106,807
Accumulated Depreciation	$ 6,806
Office [Member] | 101 J.F. Kennedy Parkway [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,981
Acquired	2,017
Related Encumbrances	$ 29,197
Initial Costs, Land	4,380
Initial Costs, Building and Improvements	59,730
Costs Capitalized Subsequent to Acquisition	1,151
Gross Amount at Which Carried at Close of Period, Land	4,380
Gross Amount at Which Carried at Close of Period, Building and Improvements	60,881
Total	65,261
Accumulated Depreciation	$ 4,063
Office [Member] | 103 J.F. Kennedy Parkway [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,981
Acquired	2,017
Related Encumbrances	$ 24,875
Initial Costs, Land	3,158
Initial Costs, Building and Improvements	50,813
Costs Capitalized Subsequent to Acquisition	469
Gross Amount at Which Carried at Close of Period, Land	3,158
Gross Amount at Which Carried at Close of Period, Building and Improvements	51,282
Total	54,440
Accumulated Depreciation	$ 3,434
Office [Member] | 111 River Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,002
Acquired	2,016
Initial Costs, Land	$ 204
Initial Costs, Building and Improvements	198,609
Costs Capitalized Subsequent to Acquisition	14,932
Gross Amount at Which Carried at Close of Period, Building and Improvements	213,745
Total	213,745
Accumulated Depreciation	$ 14,364
Office [Member] | Harborside Plaza 1 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,983
Acquired	1,996
Initial Costs, Land	$ 3,923
Initial Costs, Building and Improvements	51,013
Costs Capitalized Subsequent to Acquisition	26,426
Gross Amount at Which Carried at Close of Period, Land	3,923
Gross Amount at Which Carried at Close of Period, Building and Improvements	77,439
Total	81,362
Accumulated Depreciation	$ 41,749
Office [Member] | Harborside Plaza 2 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,990
Acquired	1,996
Initial Costs, Land	$ 17,655
Initial Costs, Building and Improvements	101,546
Costs Capitalized Subsequent to Acquisition	53,393
Gross Amount at Which Carried at Close of Period, Land	8,364
Gross Amount at Which Carried at Close of Period, Building and Improvements	164,230
Total	172,594
Accumulated Depreciation	$ 69,838
Office [Member] | Harborside Plaza 3 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,990
Acquired	1,996
Initial Costs, Land	$ 17,655
Initial Costs, Building and Improvements	101,878
Costs Capitalized Subsequent to Acquisition	53,060
Gross Amount at Which Carried at Close of Period, Land	8,363
Gross Amount at Which Carried at Close of Period, Building and Improvements	164,230
Total	172,593
Accumulated Depreciation	$ 69,838
Office [Member] | Harborside Plaza 4A [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,000
Acquired	2,000
Initial Costs, Land	$ 1,244
Initial Costs, Building and Improvements	56,144
Costs Capitalized Subsequent to Acquisition	8,688
Gross Amount at Which Carried at Close of Period, Land	1,244
Gross Amount at Which Carried at Close of Period, Building and Improvements	64,832
Total	66,076
Accumulated Depreciation	$ 31,301
Office [Member] | Harborside Plaza 5 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,002
Acquired	2,002
Initial Costs, Land	$ 6,218
Initial Costs, Building and Improvements	170,682
Costs Capitalized Subsequent to Acquisition	60,698
Gross Amount at Which Carried at Close of Period, Land	5,705
Gross Amount at Which Carried at Close of Period, Building and Improvements	231,893
Total	237,598
Accumulated Depreciation	$ 101,850
Office [Member] | 101 Hudson [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,992
Acquired	2,005
Related Encumbrances	$ 248,460
Initial Costs, Land	45,530
Initial Costs, Building and Improvements	271,376
Costs Capitalized Subsequent to Acquisition	33,508
Gross Amount at Which Carried at Close of Period, Land	45,530
Gross Amount at Which Carried at Close of Period, Building and Improvements	304,884
Total	350,414
Accumulated Depreciation	$ 103,639
Office [Member] | 100 Overlook Center [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,988
Acquired	1,997
Initial Costs, Land	$ 2,378
Initial Costs, Building and Improvements	21,754
Costs Capitalized Subsequent to Acquisition	4,577
Gross Amount at Which Carried at Close of Period, Land	2,378
Gross Amount at Which Carried at Close of Period, Building and Improvements	26,331
Total	28,709
Accumulated Depreciation	$ 13,218
Office [Member] | 5 Vaughn Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,995
Initial Costs, Land	$ 657
Initial Costs, Building and Improvements	9,800
Costs Capitalized Subsequent to Acquisition	1,564
Gross Amount at Which Carried at Close of Period, Land	657
Gross Amount at Which Carried at Close of Period, Building and Improvements	11,364
Total	12,021
Accumulated Depreciation	$ 6,529
Office [Member] | 333 Thornall Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,984
Acquired	2,015
Initial Costs, Land	$ 5,542
Initial Costs, Building and Improvements	40,762
Costs Capitalized Subsequent to Acquisition	3,686
Gross Amount at Which Carried at Close of Period, Land	5,542
Gross Amount at Which Carried at Close of Period, Building and Improvements	44,448
Total	49,990
Accumulated Depreciation	$ 4,933
Office [Member] | 343 Thornall Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,991
Acquired	2,006
Initial Costs, Land	$ 6,027
Initial Costs, Building and Improvements	39,101
Costs Capitalized Subsequent to Acquisition	15,160
Gross Amount at Which Carried at Close of Period, Land	6,027
Gross Amount at Which Carried at Close of Period, Building and Improvements	54,261
Total	60,288
Accumulated Depreciation	$ 16,308
Office [Member] | 101 Wood Avenue South [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,990
Acquired	2,016
Initial Costs, Land	$ 8,509
Initial Costs, Building and Improvements	72,738
Costs Capitalized Subsequent to Acquisition	1,183
Gross Amount at Which Carried at Close of Period, Land	7,384
Gross Amount at Which Carried at Close of Period, Building and Improvements	75,046
Total	82,430
Accumulated Depreciation	$ 6,936
Office [Member] | 500 College Road East [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,984
Acquired	1,998
Initial Costs, Land	$ 614
Initial Costs, Building and Improvements	20,626
Costs Capitalized Subsequent to Acquisition	5,776
Gross Amount at Which Carried at Close of Period, Land	614
Gross Amount at Which Carried at Close of Period, Building and Improvements	26,402
Total	27,016
Accumulated Depreciation	$ 14,225
Office [Member] | 581 Main Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,991
Acquired	1,997
Initial Costs, Land	$ 3,237
Initial Costs, Building and Improvements	12,949
Costs Capitalized Subsequent to Acquisition	35,315
Gross Amount at Which Carried at Close of Period, Land	8,115
Gross Amount at Which Carried at Close of Period, Building and Improvements	43,386
Total	51,501
Accumulated Depreciation	$ 16,482
Office [Member] | 23 Main Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,977
Acquired	2,005
Initial Costs, Land	$ 4,336
Initial Costs, Building and Improvements	19,544
Costs Capitalized Subsequent to Acquisition	6,377
Gross Amount at Which Carried at Close of Period, Land	4,336
Gross Amount at Which Carried at Close of Period, Building and Improvements	25,921
Total	30,257
Accumulated Depreciation	$ 8,116
Office [Member] | One River Center, Building 1 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,983
Acquired	2,004
Initial Costs, Land	$ 3,070
Initial Costs, Building and Improvements	17,414
Costs Capitalized Subsequent to Acquisition	16,094
Gross Amount at Which Carried at Close of Period, Land	2,451
Gross Amount at Which Carried at Close of Period, Building and Improvements	34,127
Total	36,578
Accumulated Depreciation	$ 8,385
Office [Member] | One River Center, Building 2 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,983
Acquired	2,004
Initial Costs, Land	$ 2,468
Initial Costs, Building and Improvements	15,043
Costs Capitalized Subsequent to Acquisition	4,175
Gross Amount at Which Carried at Close of Period, Land	2,452
Gross Amount at Which Carried at Close of Period, Building and Improvements	19,234
Total	21,686
Accumulated Depreciation	$ 7,880
Office [Member] | One River Center, Building 3 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,984
Acquired	2,004
Initial Costs, Land	$ 4,051
Initial Costs, Building and Improvements	24,790
Costs Capitalized Subsequent to Acquisition	5,688
Gross Amount at Which Carried at Close of Period, Land	4,627
Gross Amount at Which Carried at Close of Period, Building and Improvements	29,902
Total	34,529
Accumulated Depreciation	$ 11,525
Office [Member] | 3600 Route 66 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,989
Acquired	1,995
Initial Costs, Land	$ 1,098
Initial Costs, Building and Improvements	18,146
Costs Capitalized Subsequent to Acquisition	11,461
Gross Amount at Which Carried at Close of Period, Land	1,098
Gross Amount at Which Carried at Close of Period, Building and Improvements	29,607
Total	30,705
Accumulated Depreciation	$ 15,555
Office [Member] | 100 Schultz Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,989
Acquired	2,017
Initial Costs, Land	$ 1,953
Initial Costs, Building and Improvements	6,790
Costs Capitalized Subsequent to Acquisition	1,126
Gross Amount at Which Carried at Close of Period, Land	1,953
Gross Amount at Which Carried at Close of Period, Building and Improvements	7,916
Total	9,869
Accumulated Depreciation	$ 905
Office [Member] | 200 Schultz Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,989
Acquired	2,017
Initial Costs, Land	$ 2,184
Initial Costs, Building and Improvements	8,259
Costs Capitalized Subsequent to Acquisition	1,165
Gross Amount at Which Carried at Close of Period, Land	2,184
Gross Amount at Which Carried at Close of Period, Building and Improvements	9,424
Total	11,608
Accumulated Depreciation	$ 1,003
Office [Member] | 325 Columbia Parkway [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,994
Initial Costs, Land	$ 1,564
Costs Capitalized Subsequent to Acquisition	18,616
Gross Amount at Which Carried at Close of Period, Land	1,564
Gross Amount at Which Carried at Close of Period, Building and Improvements	18,616
Total	20,180
Accumulated Depreciation	$ 13,036
Office [Member] | 1 Giralda Farms [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,982
Acquired	2,017
Initial Costs, Land	$ 3,370
Initial Costs, Building and Improvements	27,145
Costs Capitalized Subsequent to Acquisition	734
Gross Amount at Which Carried at Close of Period, Land	3,370
Gross Amount at Which Carried at Close of Period, Building and Improvements	27,879
Total	31,249
Accumulated Depreciation	$ 2,260
Office [Member] | 7 Giralda Farms [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,997
Acquired	2,017
Initial Costs, Land	$ 5,402
Initial Costs, Building and Improvements	5,402
Costs Capitalized Subsequent to Acquisition	510
Gross Amount at Which Carried at Close of Period, Land	5,402
Gross Amount at Which Carried at Close of Period, Building and Improvements	38,174
Total	43,576
Accumulated Depreciation	$ 2,766
Office [Member] | 4 Campus Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,983
Acquired	2,001
Initial Costs, Land	$ 5,213
Initial Costs, Building and Improvements	20,984
Costs Capitalized Subsequent to Acquisition	4,052
Gross Amount at Which Carried at Close of Period, Land	5,213
Gross Amount at Which Carried at Close of Period, Building and Improvements	25,036
Total	30,249
Accumulated Depreciation	$ 11,490
Office [Member] | 6 Campus Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,983
Acquired	2,001
Initial Costs, Land	$ 4,411
Initial Costs, Building and Improvements	17,796
Costs Capitalized Subsequent to Acquisition	3,945
Gross Amount at Which Carried at Close of Period, Land	4,411
Gross Amount at Which Carried at Close of Period, Building and Improvements	21,741
Total	26,152
Accumulated Depreciation	$ 9,665
Office [Member] | 7 Campus Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,982
Acquired	1,998
Initial Costs, Land	$ 1,932
Initial Costs, Building and Improvements	27,788
Costs Capitalized Subsequent to Acquisition	6,757
Gross Amount at Which Carried at Close of Period, Land	1,932
Gross Amount at Which Carried at Close of Period, Building and Improvements	34,545
Total	36,477
Accumulated Depreciation	$ 18,408
Office [Member] | 8 Campus Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,998
Initial Costs, Land	$ 1,865
Initial Costs, Building and Improvements	35,456
Costs Capitalized Subsequent to Acquisition	12,475
Gross Amount at Which Carried at Close of Period, Land	1,865
Gross Amount at Which Carried at Close of Period, Building and Improvements	47,931
Total	49,796
Accumulated Depreciation	$ 22,089
Office [Member] | 9 Campus Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,983
Acquired	2,001
Initial Costs, Land	$ 3,277
Initial Costs, Building and Improvements	11,796
Costs Capitalized Subsequent to Acquisition	22,721
Gross Amount at Which Carried at Close of Period, Land	5,842
Gross Amount at Which Carried at Close of Period, Building and Improvements	31,952
Total	37,794
Accumulated Depreciation	$ 13,474
Office [Member] | 2 Dryden Way [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,990
Acquired	1,998
Initial Costs, Land	$ 778
Initial Costs, Building and Improvements	420
Costs Capitalized Subsequent to Acquisition	110
Gross Amount at Which Carried at Close of Period, Land	778
Gross Amount at Which Carried at Close of Period, Building and Improvements	530
Total	1,308
Accumulated Depreciation	$ 320
Office [Member] | 4 Gatehall Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,988
Acquired	2,000
Initial Costs, Land	$ 8,452
Initial Costs, Building and Improvements	33,929
Costs Capitalized Subsequent to Acquisition	7,788
Gross Amount at Which Carried at Close of Period, Land	8,452
Gross Amount at Which Carried at Close of Period, Building and Improvements	41,717
Total	50,169
Accumulated Depreciation	$ 18,726
Office [Member] | 2 Hilton Court [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,991
Acquired	1,998
Initial Costs, Land	$ 1,971
Initial Costs, Building and Improvements	32,007
Costs Capitalized Subsequent to Acquisition	4,474
Gross Amount at Which Carried at Close of Period, Land	1,971
Gross Amount at Which Carried at Close of Period, Building and Improvements	36,481
Total	38,452
Accumulated Depreciation	$ 19,992
Office [Member] | 1 Sylvan Way [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,989
Acquired	1,998
Initial Costs, Land	$ 1,689
Initial Costs, Building and Improvements	24,699
Costs Capitalized Subsequent to Acquisition	4,984
Gross Amount at Which Carried at Close of Period, Land	1,021
Gross Amount at Which Carried at Close of Period, Building and Improvements	30,351
Total	31,372
Accumulated Depreciation	$ 14,094
Office [Member] | 3 Sylvan Way [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,988
Acquired	2,015
Initial Costs, Land	$ 5,590
Initial Costs, Building and Improvements	4,710
Costs Capitalized Subsequent to Acquisition	9,840
Gross Amount at Which Carried at Close of Period, Land	5,590
Gross Amount at Which Carried at Close of Period, Building and Improvements	14,550
Total	20,140
Accumulated Depreciation	$ 845
Office [Member] | 5 Sylvan Way [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,989
Acquired	1,998
Initial Costs, Land	$ 1,160
Initial Costs, Building and Improvements	25,214
Costs Capitalized Subsequent to Acquisition	7,056
Gross Amount at Which Carried at Close of Period, Land	1,161
Gross Amount at Which Carried at Close of Period, Building and Improvements	32,269
Total	33,430
Accumulated Depreciation	$ 14,774
Office [Member] | 7 Sylvan Way [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,998
Initial Costs, Land	$ 2,084
Initial Costs, Building and Improvements	26,083
Costs Capitalized Subsequent to Acquisition	14,823
Gross Amount at Which Carried at Close of Period, Land	2,084
Gross Amount at Which Carried at Close of Period, Building and Improvements	40,906
Total	42,990
Accumulated Depreciation	$ 15,697
Office [Member] | 5 Wood Hollow Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,979
Acquired	2,004
Initial Costs, Land	$ 5,302
Initial Costs, Building and Improvements	26,488
Costs Capitalized Subsequent to Acquisition	21,087
Gross Amount at Which Carried at Close of Period, Land	5,302
Gross Amount at Which Carried at Close of Period, Building and Improvements	47,575
Total	52,877
Accumulated Depreciation	$ 21,689
Office [Member] | 100 Clearbrook Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,975
Acquired	1,997
Initial Costs, Land	$ 220
Initial Costs, Building and Improvements	5,366
Costs Capitalized Subsequent to Acquisition	1,846
Gross Amount at Which Carried at Close of Period, Land	220
Gross Amount at Which Carried at Close of Period, Building and Improvements	7,212
Total	7,432
Accumulated Depreciation	$ 3,620
Office [Member] | 101 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,971
Acquired	1,997
Initial Costs, Land	$ 267
Initial Costs, Building and Improvements	5,838
Costs Capitalized Subsequent to Acquisition	$ (6,105)
Office [Member] | 1 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,980
Acquired	1,997
Initial Costs, Land	$ 66
Initial Costs, Building and Improvements	1,711
Costs Capitalized Subsequent to Acquisition	210
Gross Amount at Which Carried at Close of Period, Land	66
Gross Amount at Which Carried at Close of Period, Building and Improvements	1,921
Total	1,987
Accumulated Depreciation	$ 1,102
Office [Member] | 2 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,997
Initial Costs, Land	$ 109
Initial Costs, Building and Improvements	3,128
Costs Capitalized Subsequent to Acquisition	1,474
Gross Amount at Which Carried at Close of Period, Land	109
Gross Amount at Which Carried at Close of Period, Building and Improvements	4,602
Total	4,711
Accumulated Depreciation	$ 2,909
Office [Member] | 7 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,998
Initial Costs, Land	$ 330
Initial Costs, Building and Improvements	13,013
Costs Capitalized Subsequent to Acquisition	2,733
Gross Amount at Which Carried at Close of Period, Land	330
Gross Amount at Which Carried at Close of Period, Building and Improvements	15,746
Total	16,076
Accumulated Depreciation	$ 8,071
Office [Member] | 17 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,989
Acquired	1,997
Initial Costs, Building and Improvements	$ 7,269
Costs Capitalized Subsequent to Acquisition	1,248
Gross Amount at Which Carried at Close of Period, Building and Improvements	8,517
Total	8,517
Accumulated Depreciation	$ 4,547
Office [Member] | 1 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,982
Acquired	1,997
Initial Costs, Land	$ 1,104
Initial Costs, Building and Improvements	11,904
Costs Capitalized Subsequent to Acquisition	3,688
Gross Amount at Which Carried at Close of Period, Land	1,105
Gross Amount at Which Carried at Close of Period, Building and Improvements	15,591
Total	16,696
Accumulated Depreciation	$ 8,210
Office [Member] | 3 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,997
Initial Costs, Land	$ 385
Initial Costs, Building and Improvements	6,256
Costs Capitalized Subsequent to Acquisition	1,803
Gross Amount at Which Carried at Close of Period, Land	385
Gross Amount at Which Carried at Close of Period, Building and Improvements	8,059
Total	8,444
Accumulated Depreciation	$ 4,496
Office [Member] | 3 Odell Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,984
Acquired	2,003
Initial Costs, Land	$ 1,322
Initial Costs, Building and Improvements	4,777
Costs Capitalized Subsequent to Acquisition	2,360
Gross Amount at Which Carried at Close of Period, Land	1,322
Gross Amount at Which Carried at Close of Period, Building and Improvements	7,137
Total	8,459
Accumulated Depreciation	$ 3,976
Office And Office/Flex Buildings [Member] | 11 Clearbrook Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,974
Acquired	1,997
Initial Costs, Land	$ 149
Initial Costs, Building and Improvements	2,159
Costs Capitalized Subsequent to Acquisition	504
Gross Amount at Which Carried at Close of Period, Land	149
Gross Amount at Which Carried at Close of Period, Building and Improvements	2,663
Total	2,812
Accumulated Depreciation	$ 1,479
Office And Office/Flex Buildings [Member] | 75 Clearbrook Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,990
Acquired	1,997
Initial Costs, Land	$ 2,314
Initial Costs, Building and Improvements	4,716
Costs Capitalized Subsequent to Acquisition	57
Gross Amount at Which Carried at Close of Period, Land	2,314
Gross Amount at Which Carried at Close of Period, Building and Improvements	4,773
Total	7,087
Accumulated Depreciation	$ 2,621
Office And Office/Flex Buildings [Member] | 125 Clearbrook Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,002
Acquired	2,002
Initial Costs, Land	$ 1,055
Initial Costs, Building and Improvements	3,676
Costs Capitalized Subsequent to Acquisition	(292)
Gross Amount at Which Carried at Close of Period, Land	1,055
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,384
Total	4,439
Accumulated Depreciation	$ 1,685
Office And Office/Flex Buildings [Member] | 150 Clearbrook Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,975
Acquired	1,997
Initial Costs, Land	$ 497
Initial Costs, Building and Improvements	7,030
Costs Capitalized Subsequent to Acquisition	2,198
Gross Amount at Which Carried at Close of Period, Land	497
Gross Amount at Which Carried at Close of Period, Building and Improvements	9,228
Total	9,725
Accumulated Depreciation	$ 4,927
Office And Office/Flex Buildings [Member] | 175 Clearbrook Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,973
Acquired	1,997
Initial Costs, Land	$ 655
Initial Costs, Building and Improvements	7,473
Costs Capitalized Subsequent to Acquisition	973
Gross Amount at Which Carried at Close of Period, Land	655
Gross Amount at Which Carried at Close of Period, Building and Improvements	8,446
Total	9,101
Accumulated Depreciation	$ 4,731
Office And Office/Flex Buildings [Member] | 200 Clearbrook Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,974
Acquired	1,997
Initial Costs, Land	$ 579
Initial Costs, Building and Improvements	6,620
Costs Capitalized Subsequent to Acquisition	1,667
Gross Amount at Which Carried at Close of Period, Land	579
Gross Amount at Which Carried at Close of Period, Building and Improvements	8,287
Total	8,866
Accumulated Depreciation	$ 4,343
Office And Office/Flex Buildings [Member] | 250 Clearbrook Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,973
Acquired	1,997
Initial Costs, Land	$ 867
Initial Costs, Building and Improvements	8,647
Costs Capitalized Subsequent to Acquisition	2,387
Gross Amount at Which Carried at Close of Period, Land	867
Gross Amount at Which Carried at Close of Period, Building and Improvements	11,034
Total	11,901
Accumulated Depreciation	$ 5,813
Office And Office/Flex Buildings [Member] | 50 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,969
Acquired	1,997
Initial Costs, Land	$ 237
Initial Costs, Building and Improvements	2,617
Costs Capitalized Subsequent to Acquisition	540
Gross Amount at Which Carried at Close of Period, Land	237
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,157
Total	3,394
Accumulated Depreciation	$ 1,731
Office And Office/Flex Buildings [Member] | 77 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,977
Acquired	1,997
Initial Costs, Land	$ 34
Initial Costs, Building and Improvements	1,104
Costs Capitalized Subsequent to Acquisition	179
Gross Amount at Which Carried at Close of Period, Land	34
Gross Amount at Which Carried at Close of Period, Building and Improvements	1,283
Total	1,317
Accumulated Depreciation	$ 740
Office And Office/Flex Buildings [Member] | 85 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,968
Acquired	1,997
Initial Costs, Land	$ 155
Initial Costs, Building and Improvements	2,507
Costs Capitalized Subsequent to Acquisition	456
Gross Amount at Which Carried at Close of Period, Land	155
Gross Amount at Which Carried at Close of Period, Building and Improvements	2,963
Total	3,118
Accumulated Depreciation	$ 1,584
Office And Office/Flex Buildings [Member] | 300 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,970
Acquired	1,997
Initial Costs, Land	$ 460
Initial Costs, Building and Improvements	3,609
Costs Capitalized Subsequent to Acquisition	307
Gross Amount at Which Carried at Close of Period, Land	460
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,916
Total	4,376
Accumulated Depreciation	$ 2,132
Office And Office/Flex Buildings [Member] | 350 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,970
Acquired	1,997
Initial Costs, Land	$ 100
Initial Costs, Building and Improvements	1,793
Costs Capitalized Subsequent to Acquisition	175
Gross Amount at Which Carried at Close of Period, Land	100
Gross Amount at Which Carried at Close of Period, Building and Improvements	1,968
Total	2,068
Accumulated Depreciation	$ 1,146
Office And Office/Flex Buildings [Member] | 399 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,962
Acquired	1,997
Initial Costs, Land	$ 531
Initial Costs, Building and Improvements	7,191
Costs Capitalized Subsequent to Acquisition	163
Gross Amount at Which Carried at Close of Period, Land	531
Gross Amount at Which Carried at Close of Period, Building and Improvements	7,354
Total	7,885
Accumulated Depreciation	$ 4,077
Office And Office/Flex Buildings [Member] | 400 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,970
Acquired	1,997
Initial Costs, Land	$ 2,202
Initial Costs, Building and Improvements	1,846
Costs Capitalized Subsequent to Acquisition	1,140
Gross Amount at Which Carried at Close of Period, Land	2,202
Gross Amount at Which Carried at Close of Period, Building and Improvements	2,986
Total	5,188
Accumulated Depreciation	$ 1,807
Office And Office/Flex Buildings [Member] | 500 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,970
Acquired	1,997
Initial Costs, Land	$ 258
Initial Costs, Building and Improvements	4,183
Costs Capitalized Subsequent to Acquisition	508
Gross Amount at Which Carried at Close of Period, Land	258
Gross Amount at Which Carried at Close of Period, Building and Improvements	4,691
Total	4,949
Accumulated Depreciation	$ 2,655
Office And Office/Flex Buildings [Member] | 525 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,972
Acquired	1,997
Initial Costs, Land	$ 345
Initial Costs, Building and Improvements	5,499
Costs Capitalized Subsequent to Acquisition	837
Gross Amount at Which Carried at Close of Period, Land	345
Gross Amount at Which Carried at Close of Period, Building and Improvements	6,336
Total	6,681
Accumulated Depreciation	$ 3,661
Office And Office/Flex Buildings [Member] | 1 Westchester Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,967
Acquired	1,997
Initial Costs, Land	$ 199
Initial Costs, Building and Improvements	2,023
Costs Capitalized Subsequent to Acquisition	183
Gross Amount at Which Carried at Close of Period, Land	199
Gross Amount at Which Carried at Close of Period, Building and Improvements	2,206
Total	2,405
Accumulated Depreciation	$ 1,214
Office And Office/Flex Buildings [Member] | 2 Westchester Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,968
Acquired	1,997
Initial Costs, Land	$ 234
Initial Costs, Building and Improvements	2,726
Costs Capitalized Subsequent to Acquisition	914
Gross Amount at Which Carried at Close of Period, Land	234
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,640
Total	3,874
Accumulated Depreciation	$ 1,971
Office And Office/Flex Buildings [Member] | 3 Westchester Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,969
Acquired	1,997
Initial Costs, Land	$ 655
Initial Costs, Building and Improvements	7,936
Costs Capitalized Subsequent to Acquisition	1,433
Gross Amount at Which Carried at Close of Period, Land	655
Gross Amount at Which Carried at Close of Period, Building and Improvements	9,369
Total	10,024
Accumulated Depreciation	$ 4,876
Office And Office/Flex Buildings [Member] | 4 Westchester Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,969
Acquired	1,997
Initial Costs, Land	$ 320
Initial Costs, Building and Improvements	3,729
Costs Capitalized Subsequent to Acquisition	1,531
Gross Amount at Which Carried at Close of Period, Land	320
Gross Amount at Which Carried at Close of Period, Building and Improvements	5,260
Total	5,580
Accumulated Depreciation	$ 2,512
Office And Office/Flex Buildings [Member] | 5 Westchester Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,969
Acquired	1,997
Initial Costs, Land	$ 118
Initial Costs, Building and Improvements	1,949
Costs Capitalized Subsequent to Acquisition	303
Gross Amount at Which Carried at Close of Period, Land	118
Gross Amount at Which Carried at Close of Period, Building and Improvements	2,252
Total	2,370
Accumulated Depreciation	$ 1,184
Office And Office/Flex Buildings [Member] | 6 Westchester Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,968
Acquired	1,997
Initial Costs, Land	$ 164
Initial Costs, Building and Improvements	1,998
Costs Capitalized Subsequent to Acquisition	202
Gross Amount at Which Carried at Close of Period, Land	164
Gross Amount at Which Carried at Close of Period, Building and Improvements	2,200
Total	2,364
Accumulated Depreciation	$ 1,197
Office And Office/Flex Buildings [Member] | 7 Westchester Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,972
Acquired	1,997
Initial Costs, Land	$ 286
Initial Costs, Building and Improvements	4,321
Costs Capitalized Subsequent to Acquisition	1,168
Gross Amount at Which Carried at Close of Period, Land	286
Gross Amount at Which Carried at Close of Period, Building and Improvements	5,489
Total	5,775
Accumulated Depreciation	$ 2,781
Office And Office/Flex Buildings [Member] | 8 Westchester Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,971
Acquired	1,997
Initial Costs, Land	$ 447
Initial Costs, Building and Improvements	5,262
Costs Capitalized Subsequent to Acquisition	2,127
Gross Amount at Which Carried at Close of Period, Land	447
Gross Amount at Which Carried at Close of Period, Building and Improvements	7,389
Total	7,836
Accumulated Depreciation	$ 4,025
Office And Office/Flex Buildings [Member] | 200 Saw Mill River Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,965
Acquired	1,997
Initial Costs, Land	$ 353
Initial Costs, Building and Improvements	3,353
Costs Capitalized Subsequent to Acquisition	833
Gross Amount at Which Carried at Close of Period, Land	353
Gross Amount at Which Carried at Close of Period, Building and Improvements	4,186
Total	4,539
Accumulated Depreciation	$ 2,110
Office And Office/Flex Buildings [Member] | 4 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,997
Initial Costs, Land	$ 363
Initial Costs, Building and Improvements	7,513
Costs Capitalized Subsequent to Acquisition	2,140
Gross Amount at Which Carried at Close of Period, Land	363
Gross Amount at Which Carried at Close of Period, Building and Improvements	9,653
Total	10,016
Accumulated Depreciation	$ 5,635
Office And Office/Flex Buildings [Member] | 5 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,980
Acquired	2,001
Initial Costs, Land	$ 2,219
Initial Costs, Building and Improvements	8,916
Costs Capitalized Subsequent to Acquisition	1,472
Gross Amount at Which Carried at Close of Period, Land	2,219
Gross Amount at Which Carried at Close of Period, Building and Improvements	10,388
Total	12,607
Accumulated Depreciation	$ 5,340
Office And Office/Flex Buildings [Member] | 6 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,980
Acquired	2,001
Initial Costs, Land	$ 740
Initial Costs, Building and Improvements	2,971
Costs Capitalized Subsequent to Acquisition	535
Gross Amount at Which Carried at Close of Period, Land	740
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,506
Total	4,246
Accumulated Depreciation	$ 1,942
Office And Office/Flex Buildings [Member] | 8 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,985
Acquired	1,997
Initial Costs, Land	$ 212
Initial Costs, Building and Improvements	4,410
Costs Capitalized Subsequent to Acquisition	836
Gross Amount at Which Carried at Close of Period, Land	212
Gross Amount at Which Carried at Close of Period, Building and Improvements	5,246
Total	5,458
Accumulated Depreciation	$ 3,036
Office And Office/Flex Buildings [Member] | 10 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,985
Acquired	1,997
Initial Costs, Land	$ 134
Initial Costs, Building and Improvements	2,799
Costs Capitalized Subsequent to Acquisition	271
Gross Amount at Which Carried at Close of Period, Land	134
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,070
Total	3,204
Accumulated Depreciation	$ 1,630
Office And Office/Flex Buildings [Member] | 11 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,989
Acquired	1,997
Initial Costs, Building and Improvements	$ 4,788
Costs Capitalized Subsequent to Acquisition	763
Gross Amount at Which Carried at Close of Period, Building and Improvements	5,551
Total	5,551
Accumulated Depreciation	$ 2,906
Office And Office/Flex Buildings [Member] | 12 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,999
Acquired	1,999
Initial Costs, Land	$ 1,562
Initial Costs, Building and Improvements	3,254
Costs Capitalized Subsequent to Acquisition	218
Gross Amount at Which Carried at Close of Period, Land	1,320
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,714
Total	5,034
Accumulated Depreciation	$ 1,911
Office And Office/Flex Buildings [Member] | 15 Skyline Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,989
Acquired	1,997
Initial Costs, Building and Improvements	$ 7,449
Costs Capitalized Subsequent to Acquisition	1,858
Gross Amount at Which Carried at Close of Period, Building and Improvements	9,307
Total	9,307
Accumulated Depreciation	$ 4,537
Office And Office/Flex Buildings [Member] | 100 Corporate Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,997
Initial Costs, Land	$ 602
Initial Costs, Building and Improvements	9,910
Costs Capitalized Subsequent to Acquisition	1,175
Gross Amount at Which Carried at Close of Period, Land	602
Gross Amount at Which Carried at Close of Period, Building and Improvements	11,085
Total	11,687
Accumulated Depreciation	$ 6,143
Office And Office/Flex Buildings [Member] | 200 Corporate Boulevard South [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,990
Acquired	1,997
Initial Costs, Land	$ 502
Initial Costs, Building and Improvements	7,575
Costs Capitalized Subsequent to Acquisition	2,585
Gross Amount at Which Carried at Close of Period, Land	502
Gross Amount at Which Carried at Close of Period, Building and Improvements	10,160
Total	10,662
Accumulated Depreciation	$ 5,017
Office And Office/Flex Buildings [Member] | 4 Executive Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,986
Acquired	1,997
Initial Costs, Land	$ 584
Initial Costs, Building and Improvements	6,134
Costs Capitalized Subsequent to Acquisition	854
Gross Amount at Which Carried at Close of Period, Land	584
Gross Amount at Which Carried at Close of Period, Building and Improvements	6,988
Total	7,572
Accumulated Depreciation	$ 3,723
Office And Office/Flex Buildings [Member] | 6 Executive Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,987
Acquired	1,997
Initial Costs, Land	$ 546
Initial Costs, Building and Improvements	7,246
Costs Capitalized Subsequent to Acquisition	2,212
Gross Amount at Which Carried at Close of Period, Land	546
Gross Amount at Which Carried at Close of Period, Building and Improvements	9,458
Total	10,004
Accumulated Depreciation	$ 5,127
Office And Office/Flex Buildings [Member] | 1 Odell Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,980
Acquired	1,997
Initial Costs, Land	$ 1,206
Initial Costs, Building and Improvements	6,815
Costs Capitalized Subsequent to Acquisition	2,349
Gross Amount at Which Carried at Close of Period, Land	1,206
Gross Amount at Which Carried at Close of Period, Building and Improvements	9,164
Total	10,370
Accumulated Depreciation	$ 5,093
Office And Office/Flex Buildings [Member] | 5 Odell Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,983
Acquired	1,997
Initial Costs, Land	$ 331
Initial Costs, Building and Improvements	2,988
Costs Capitalized Subsequent to Acquisition	476
Gross Amount at Which Carried at Close of Period, Land	331
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,464
Total	3,795
Accumulated Depreciation	$ 2,029
Office And Office/Flex Buildings [Member] | 7 Odell Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,984
Acquired	1,997
Initial Costs, Land	$ 419
Initial Costs, Building and Improvements	4,418
Costs Capitalized Subsequent to Acquisition	1,303
Gross Amount at Which Carried at Close of Period, Land	419
Gross Amount at Which Carried at Close of Period, Building and Improvements	5,721
Total	6,140
Accumulated Depreciation	$ 2,938
Office And Office/Flex Buildings [Member] | 419 West Avenue [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,986
Acquired	1,997
Initial Costs, Land	$ 4,538
Initial Costs, Building and Improvements	9,246
Costs Capitalized Subsequent to Acquisition	482
Gross Amount at Which Carried at Close of Period, Land	4,538
Gross Amount at Which Carried at Close of Period, Building and Improvements	9,728
Total	14,266
Accumulated Depreciation	$ 5,316
Office And Office/Flex Buildings [Member] | 500 West Avenue [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,988
Acquired	1,997
Initial Costs, Land	$ 415
Initial Costs, Building and Improvements	1,679
Costs Capitalized Subsequent to Acquisition	646
Gross Amount at Which Carried at Close of Period, Land	415
Gross Amount at Which Carried at Close of Period, Building and Improvements	2,325
Total	2,740
Accumulated Depreciation	$ 1,221
Office And Office/Flex Buildings [Member] | 550 West Avenue [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,990
Acquired	1,997
Initial Costs, Land	$ 1,975
Initial Costs, Building and Improvements	3,856
Costs Capitalized Subsequent to Acquisition	133
Gross Amount at Which Carried at Close of Period, Land	1,975
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,989
Total	5,964
Accumulated Depreciation	$ 2,172
Office And Office/Flex Buildings [Member] | 600 West Avenue [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,999
Acquired	1,999
Initial Costs, Land	$ 2,305
Initial Costs, Building and Improvements	2,863
Costs Capitalized Subsequent to Acquisition	1,184
Gross Amount at Which Carried at Close of Period, Land	2,305
Gross Amount at Which Carried at Close of Period, Building and Improvements	4,047
Total	6,352
Accumulated Depreciation	$ 1,739
Office And Office/Flex Buildings [Member] | 650 West Avenue [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,998
Acquired	1,998
Initial Costs, Land	$ 1,328
Costs Capitalized Subsequent to Acquisition	3,247
Gross Amount at Which Carried at Close of Period, Land	1,328
Gross Amount at Which Carried at Close of Period, Building and Improvements	3,247
Total	4,575
Accumulated Depreciation	$ 1,805
Retail [Member] | 230 White Plains Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,984
Acquired	1,997
Initial Costs, Land	$ 124
Initial Costs, Building and Improvements	1,845
Costs Capitalized Subsequent to Acquisition	288
Gross Amount at Which Carried at Close of Period, Land	124
Gross Amount at Which Carried at Close of Period, Building and Improvements	2,133
Total	2,257
Accumulated Depreciation	$ 1,108
Retail [Member] | 2 Executive Boulevard [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,986
Acquired	1,997
Initial Costs, Land	$ 89
Initial Costs, Building and Improvements	2,439
Costs Capitalized Subsequent to Acquisition	107
Gross Amount at Which Carried at Close of Period, Land	89
Gross Amount at Which Carried at Close of Period, Building and Improvements	2,546
Total	2,635
Accumulated Depreciation	$ 1,397
Multi-Family Properties [Member] | RoseGarden Monaco, L.L.C. [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,011
Acquired	2,017
Related Encumbrances	$ 168,370
Initial Costs, Land	58,761
Initial Costs, Building and Improvements	240,871
Costs Capitalized Subsequent to Acquisition	434
Gross Amount at Which Carried at Close of Period, Land	58,761
Gross Amount at Which Carried at Close of Period, Building and Improvements	241,305
Total	300,066
Accumulated Depreciation	$ 10,720
Multi-Family Properties [Member] | Marbella I [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,003
Acquired	2,018
Related Encumbrances	$ 130,040
Initial Costs, Land	48,820
Initial Costs, Building and Improvements	160,740
Costs Capitalized Subsequent to Acquisition	1,306
Gross Amount at Which Carried at Close of Period, Land	48,820
Gross Amount at Which Carried at Close of Period, Building and Improvements	162,046
Total	210,866
Accumulated Depreciation	$ 1,711
Multi-Family Properties [Member] | Port Imperial South 11 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,018
Acquired	2,018
Related Encumbrances	$ 99,792
Gross Amount at Which Carried at Close of Period, Land	22,047
Gross Amount at Which Carried at Close of Period, Building and Improvements	108,392
Total	130,439
Accumulated Depreciation	$ 577
Multi-Family Properties [Member] | Richmond Court [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,997
Acquired	2,013
Initial Costs, Land	$ 2,992
Initial Costs, Building and Improvements	13,534
Costs Capitalized Subsequent to Acquisition	1,908
Gross Amount at Which Carried at Close of Period, Land	2,992
Gross Amount at Which Carried at Close of Period, Building and Improvements	15,442
Total	18,434
Accumulated Depreciation	$ 1,856
Multi-Family Properties [Member] | Riverwatch Commons [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	1,995
Acquired	2,013
Initial Costs, Land	$ 4,169
Initial Costs, Building and Improvements	18,974
Costs Capitalized Subsequent to Acquisition	2,187
Gross Amount at Which Carried at Close of Period, Land	4,169
Gross Amount at Which Carried at Close of Period, Building and Improvements	21,161
Total	25,330
Accumulated Depreciation	2,534
Multi-Family Properties [Member] | Signature Place At Morris Plains [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Related Encumbrances	41,703
Initial Costs, Land	930
Costs Capitalized Subsequent to Acquisition	56,373
Gross Amount at Which Carried at Close of Period, Land	930
Gross Amount at Which Carried at Close of Period, Building and Improvements	56,373
Total	57,303
Accumulated Depreciation	$ 922
Multi-Family Properties [Member] | Quarry Place At Tuckahoe [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,016
Acquired	2,016
Related Encumbrances	$ 40,433
Initial Costs, Land	5,585
Initial Costs, Building and Improvements	3,400
Costs Capitalized Subsequent to Acquisition	48,718
Gross Amount at Which Carried at Close of Period, Land	5,585
Gross Amount at Which Carried at Close of Period, Building and Improvements	52,118
Total	57,703
Accumulated Depreciation	$ 2,573
Multi-Family Properties [Member] | The Chase At Overlook Ridge [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,016
Acquired	2,016
Related Encumbrances	$ 134,839
Initial Costs, Land	11,072
Initial Costs, Building and Improvements	87,793
Costs Capitalized Subsequent to Acquisition	74,692
Gross Amount at Which Carried at Close of Period, Land	21,827
Gross Amount at Which Carried at Close of Period, Building and Improvements	151,730
Total	173,557
Accumulated Depreciation	$ 9,969
Multi-Family Properties [Member] | Portside At Pier One [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,016
Acquired	2,016
Related Encumbrances	$ 58,644
Initial Costs, Building and Improvements	73,713
Costs Capitalized Subsequent to Acquisition	446
Gross Amount at Which Carried at Close of Period, Building and Improvements	74,159
Total	74,159
Accumulated Depreciation	$ 6,163
Multi-Family Properties [Member] | Portside 5/6 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,018
Acquired	2,018
Related Encumbrances	$ 96,369
Gross Amount at Which Carried at Close of Period, Building and Improvements	113,913
Total	113,913
Accumulated Depreciation	$ 1,268
Multi-Family Properties [Member] | Alterra At Overlook Ridge IA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,004
Acquired	2,013
Related Encumbrances	$ 40,102
Initial Costs, Land	9,042
Initial Costs, Building and Improvements	50,671
Costs Capitalized Subsequent to Acquisition	1,072
Gross Amount at Which Carried at Close of Period, Land	9,042
Gross Amount at Which Carried at Close of Period, Building and Improvements	51,743
Total	60,785
Accumulated Depreciation	$ 7,933
Multi-Family Properties [Member] | Alterra at Overlook Ridge II [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,008
Acquired	2,013
Related Encumbrances	$ 59,371
Initial Costs, Land	12,055
Initial Costs, Building and Improvements	71,409
Costs Capitalized Subsequent to Acquisition	409
Gross Amount at Which Carried at Close of Period, Land	12,056
Gross Amount at Which Carried at Close of Period, Building and Improvements	71,817
Total	83,873
Accumulated Depreciation	$ 10,980
Other Property [Member] | 100 Avenue At Port Imperial [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,016
Acquired	2,016
Initial Costs, Land	$ 350
Costs Capitalized Subsequent to Acquisition	4,205
Gross Amount at Which Carried at Close of Period, Land	471
Gross Amount at Which Carried at Close of Period, Building and Improvements	4,084
Total	4,555
Accumulated Depreciation	$ 310
Other Property [Member] | 500 Avenue At Port Imperial [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Year Built	2,013
Acquired	2,013
Related Encumbrances	$ 36,568
Initial Costs, Land	13,099
Initial Costs, Building and Improvements	56,669
Costs Capitalized Subsequent to Acquisition	(19,756)
Gross Amount at Which Carried at Close of Period, Land	13,099
Gross Amount at Which Carried at Close of Period, Building and Improvements	36,913
Total	50,012
Accumulated Depreciation	4,925
Projects Under Development And Developable Land [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Related Encumbrances	128,017
Initial Costs, Land	363,373
Initial Costs, Building and Improvements	494,764
Gross Amount at Which Carried at Close of Period, Land	363,373
Gross Amount at Which Carried at Close of Period, Building and Improvements	494,764
Total	858,137
Accumulated Depreciation	14,726
Furniture, Fixtures And Equipment [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Costs Capitalized Subsequent to Acquisition	53,718
Gross Amount at Which Carried at Close of Period, Building and Improvements	53,718
Total	53,718
Accumulated Depreciation	$ 15,879
Buildings And Improvements [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Useful Live	40 years

Real Estate Investments And A_3

Real Estate Investments And Accumulated Depreciation (Schedule Of Changes In Rental Properties And Accumulated Depreciation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Real Estate Investments And Accumulated Depreciation [Abstract]
Rental Properties, Balance at beginning of year	$ 5,102,844	$ 4,804,867	$ 4,807,718
Rental Properties, Additions	686,452	1,179,365	819,535
Rental Properties, Rental property held for sale	(184,233)	(310,089)	(79,200)
Rental Properties, Properties sold	(238,873)	(538,424)	(695,837)
Rental Properties, Impairments
Rental Properties, Retirements/disposals	(60,173)	(32,875)	(47,349)
Rental Properties, Balance at end of year	5,306,017	5,102,844	4,804,867
Accumulated Depreciation, Balance at beginning of year	1,087,083	1,332,073	1,464,482
Accumulated Depreciation, Depreciation expense	140,726	154,343	151,569
Accumulated Depreciation, Rental property held for sale	(30,404)	(126,503)	(31,792)
Accumulated Depreciation, Properties sold	(39,364)	(217,625)	(204,837)
Accumulated Depreciation, Repurposed buildings		(22,330)
Accumulated Depreciation, Impairments
Accumulated Depreciation, Retirements/disposals	(60,173)	(32,875)	(47,349)
Accumulated Depreciation, Balance at end of year	$ 1,097,868	$ 1,087,083	$ 1,332,073

Mortgage Loans On Real Estate (

Mortgage Loans On Real Estate (Schedule Of Mortgage Loans On Real Estate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Face Amount of Mortgages or Maximum Available Credit	$ 41,695
Carrying Amount of Mortgages	$ 45,242	$ 45,734
Borrower A [Member] | Land [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Accrual Rate	5.85%
Interest Payment Rate	5.85%
Final Maturity Date	Jul. 21, 2019
Periodic Payment Terms	P&I
Face Amount of Mortgages or Maximum Available Credit	$ 41,695
Carrying Amount of Mortgages	$ 45,242

Mortgage Loans On Real Estate_2

Mortgage Loans On Real Estate (Schedule Of Reconciliation On Real Estate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]
Beginning Balance	$ 45,734
New mortgage loan/(repayments)		44,695
New mortgage loan/(repayment)	(3,000)
Accrued interest	2,508	1,039
Ending Balance	$ 45,242	$ 45,734