CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 107,176	$ 2,069	$ 21,143
Other comprehensive income (loss):
Change in value of interest rate swaps	10,618	8,161	(9,241)
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	160	17	(512)
Comprehensive income	117,954	10,247	11,390
Less comprehensive (income) loss attributable to noncontrolling interests in:
Consolidated joint ventures	10,365	(15,423)	(5,459)
Consolidated real estate funds	(19,797)	1,316	(21,173)
Operating Partnership	(12,430)	2,141	2,980
Comprehensive income (loss) attributable to common stockholders	$ 96,092	$ (1,719)	$ (12,262)