CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ (DEFICIT) EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2017		12,019,701
Beginning balance at Dec. 31, 2017	$ 30,806	$ 120	$ 903,247	$ (854,921)	$ (18,879)	$ 1,239
Comprehensive income (loss):
Net (loss) income	(51,301)			(51,828)		527
Translation adjustment	(975)				(712)	(263)
Dividend payment to noncontrolling interest	(200)					(200)
Stock-based compensation expense	2,508		2,508
Exercise of stock options (in shares)		70,086
Exercise of stock options	214		214
Vesting of restricted stock units/awards (in shares)		137,844
Vesting of restricted stock units/awards	0	$ 2	(2)
Vested restricted stock cancelled for employee minimum income taxes (in shares)		(22,176)
Vested restricted stock cancelled for employee minimum income taxes	(527)	$ 0	(527)
Public equity offering (in shares)		1,820,000
Public equity offering	46,999	$ 18	46,981
Employee purchases of unregistered shares of common stock (in shares)		(22,456)
Employee purchases of unregistered shares of common stock	(610)	$ 0	(610)
Ending balance (in shares) at Sep. 30, 2018		14,002,999.000
Ending balance at Sep. 30, 2018	26,914	$ 140	951,811	(906,749)	(19,591)	1,303
Beginning balance (in shares) at Jun. 30, 2018		14,002,999.000
Beginning balance at Jun. 30, 2018	33,921	$ 140	951,349	(899,213)	(19,634)	1,279
Comprehensive income (loss):
Net (loss) income	(7,462)			(7,536)		74
Translation adjustment	(7)				43	(50)
Stock-based compensation expense	465		465
Exercise of stock options	(3)		(3)
Ending balance (in shares) at Sep. 30, 2018		14,002,999.000
Ending balance at Sep. 30, 2018	26,914	$ 140	951,811	(906,749)	(19,591)	1,303
Beginning balance (in shares) at Dec. 31, 2018		14,015,615.000
Beginning balance at Dec. 31, 2018	7,824	$ 140	952,626	(926,092)	(20,442)	1,592
Comprehensive income (loss):
Net (loss) income	(32,864)			(33,705)		841
Translation adjustment	(1,147)				(998)	(149)
Stock-based compensation expense	3,736		3,736
Exercise of stock options (in shares)		82,900
Exercise of stock options	103	$ 1	102
Vesting of restricted stock units/awards (in shares)		202,697
Vesting of restricted stock units/awards	0	$ 2	(2)
Vested restricted stock cancelled for employee minimum income taxes (in shares)		(99,562)
Vested restricted stock cancelled for employee minimum income taxes	(758)	$ (1)	(757)
Ending balance (in shares) at Sep. 30, 2019		14,201,650.00
Ending balance at Sep. 30, 2019	(23,106)	$ 142	955,705	(959,797)	(21,440)	2,284
Beginning balance (in shares) at Jun. 30, 2019		14,171,561.000
Beginning balance at Jun. 30, 2019	(19,381)	$ 142	954,904	(956,074)	(20,412)	2,059
Comprehensive income (loss):
Net (loss) income	(3,329)			(3,723)		394
Translation adjustment	(1,197)				(1,028)	(169)
Stock-based compensation expense	905		905
Exercise of stock options (in shares)		58,400
Exercise of stock options	26	$ 0	26
Vesting of restricted stock units/awards (in shares)		1,066
Vesting of restricted stock units/awards	0	$ 0	0
Vested restricted stock cancelled for employee minimum income taxes (in shares)		(29,377)
Vested restricted stock cancelled for employee minimum income taxes	(130)	$ 0	(130)
Ending balance (in shares) at Sep. 30, 2019		14,201,650.00
Ending balance at Sep. 30, 2019	$ (23,106)	$ 142	$ 955,705	$ (959,797)	$ (21,440)	$ 2,284