Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest in Subsidiary	Total
Beginning balance at Dec. 31, 2018	$ 20	$ 1,198,769	$ (688,653)	$ (2,138)	$ 17,011	$ 525,009
Beginning balance (in shares) at Dec. 31, 2018	203,599,892
Increase (Decrease) in Stockholders' Equity
Issuance of common stock, net of offering costs		175				175
Issuance of common stock, net of offering costs (in shares)	1,052,040
Stock-based compensation		1,246				1,246
Net income (loss)			(10,946)		(1,879)	(12,825)
Other comprehensive income (loss)				374		374
Increase in ownership in subsidiary		228			(228)
Ending balance at Mar. 31, 2019	$ 20	1,200,418	(699,599)	(1,764)	14,904	513,979
Ending balance (in shares) at Mar. 31, 2019	204,651,932
Beginning balance at Dec. 31, 2019	$ 20	1,203,186	(668,232)	(1,566)	9,621	$ 543,029
Beginning balance (in shares) at Dec. 31, 2019	204,723,055					204,723,055
Increase (Decrease) in Stockholders' Equity
Issuance of common stock, net of offering costs		194				$ 194
Repurchase of common stock		(4,244)				$ (4,244)
Repurchase of common stock (in shares)	(2,810,449)					(2,810,449)
Issuance of common stock, net of offering costs (in shares)	871,010
Stock-based compensation		1,054				$ 1,054
Net income (loss)			1,704		(805)	899
Other comprehensive income (loss)				(1,915)		(1,915)
Increase in ownership in subsidiary		(1,388)			1,388
Ending balance at Mar. 31, 2020	$ 20	$ 1,198,802	$ (666,528)	$ (3,481)	$ 10,204	$ 539,017
Ending balance (in shares) at Mar. 31, 2020	202,783,616					202,783,616