Consolidated Statements Of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net loss	$ (25,792)	$ (41,118)	$ (86,302)	$ (111,896)
Other comprehensive income (loss):
Net unrealized gain (loss) on derivative instruments for interest rate swaps				(16)
Comprehensive loss	(25,792)	(41,118)	(86,302)	(111,912)
Comprehensive (income) loss attributable to noncontrolling interests in consolidated joint ventures	1,137	895	3,670	1,900
Comprehensive (income) loss attributable to redeemable noncontrolling interests	(6,471)	(6,471)	(19,413)	(19,413)
Comprehensive (income) loss attributable to noncontrolling interests in Operating Partnership	2,812	4,486	9,275	12,424
Comprehensive loss attributable to common shareholders	(28,314)	(42,208)	(92,770)	(117,001)
Mack-Cali Realty LP [Member]
Net loss	(25,792)	(41,118)	(86,302)	(111,896)
Other comprehensive income (loss):
Net unrealized gain (loss) on derivative instruments for interest rate swaps				(16)
Comprehensive loss	(25,792)	(41,118)	(86,302)	(111,912)
Comprehensive (income) loss attributable to noncontrolling interests in consolidated joint ventures	1,137	895	3,670	1,900
Comprehensive (income) loss attributable to redeemable noncontrolling interests	(6,471)	(6,471)	(19,413)	(19,413)
Comprehensive loss attributable to common shareholders	$ (31,126)	$ (46,694)	$ (102,045)	$ (129,425)