CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income		$ (36,578)	$ 138,182	$ (33,863)	$ 139,811
Other comprehensive income (loss):
Change in value of interest rate swaps		5,795	(4,041)	20,346	(9)
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	[1]	103	35	157	(187)
Comprehensive (loss) income		(30,680)	134,176	(13,360)	139,615
Less comprehensive (income) loss attributable to noncontrolling interests in:
Consolidated joint ventures		(1,752)	(1,897)	(2,807)	(3,188)
Consolidated real estate fund		(152)	(20,169)	(582)	(20,081)
Operating Partnership		3,103	(12,647)	1,611	(13,187)
Comprehensive (loss) income attributable to common stockholders		$ (29,481)	$ 99,463	$ (15,138)	$ 103,159

[1] Represents foreign currency translation adjustments. No amounts were reclassified from accumulated other comprehensive income during any of the periods set forth above.