Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 3,099	$ (2,736)	$ 9,588	$ (6,702)
Other comprehensive income (loss):
Change in fair value of swap agreement	(87)	281	(17)	(50)
Total comprehensive income (loss)	3,012	(2,455)	9,571	(6,752)
Less: comprehensive (income) loss attributable to noncontrolling interests	(1)	1	(3)	3
Comprehensive income (loss) attributable to common stockholders	$ 3,011	$ (2,454)	$ 9,568	$ (6,749)