CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended							6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	[1]
Statement of Comprehensive Income [Abstract]
Net income	$ 4,071	$ (4,273)	$ (4,213)	$ 8,099	$ (3,077)	$ (4,651)	$ 25,254	$ (8,486)	$ 20,603	$ (4,415)	$ 17,526	$ 1,693	$ 25,625
Other comprehensive (loss) income:
Unrealized (loss) gain on derivative instruments	(3)	(15)	(9)					(24)		(27)		(23)
Unrealized (loss) gain on derivative instruments				(17)	5	7	17		24		29		13
Other comprehensive (loss) income	(3)	(15)	(9)	(17)	5	7	17	(24)	24	(27)	29	(23)	13
Comprehensive income	4,068	(4,288)	(4,222)	8,082	(3,072)	(4,644)	25,271	(8,510)	20,627	(4,442)	17,555	1,670	25,638
Comprehensive (income) attributable to non-controlling interests	(799)	(42)	(32)	(23)	(35)	(39)	(35)	(74)	(74)	(873)	(109)	(833)	(132)
Comprehensive income attributable to common stockholders	$ 3,269	$ (4,330)	$ (4,254)	$ 8,059	$ (3,107)	$ (4,683)	$ 25,236	$ (8,584)	$ 20,553	$ (5,315)	$ 17,446	$ 837	$ 25,506

[1] * Amounts restated See footnotes 2 and 16 for more information.