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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(43,839)			(44,292)		453
Translation adjustment	(968)				(755)	(213)
Dividend payment to noncontrolling interest	(200)					(200)
Stock-based compensation expense	2,043		2,043
Exercise of stock options (in shares)		70,086
Exercise of stock options	217	$ 0	217
Vesting of restricted stock units/ awards (in shares)		137,844
Vesting of restricted stock units/awards	0	$ 2	(2)
Restricted stock cancelled for employee minimum income taxes (in shares)		(44,632)
Restricted stock cancelled for employee minimum income taxes	(1,137)	$ 0	(1,137)
Public equity offering (in shares)		1,820,000
Public equity offering	46,999	$ 18	46,981
Ending balance (in shares) at Jun. 30, 2018		14,002,999.000
Ending balance at Jun. 30, 2018	33,921	$ 140	951,349	(899,213)	(19,634)	1,279
Beginning balance (in shares) at Mar. 31, 2018		13,909,509.000
Beginning balance at Mar. 31, 2018	61,519	$ 139	950,464	(873,347)	(17,054)	1,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(25,500)			(25,866)		366
Translation adjustment	(2,784)				(2,580)	(204)
Dividend payment to noncontrolling interest	(200)					(200)
Stock-based compensation expense	1,231		1,231
Exercise of stock options (in shares)		58,836
Exercise of stock options	182	$ 0	182
Vesting of restricted stock units/ awards (in shares)		56,830
Vesting of restricted stock units/awards	0	$ 1	(1)
Restricted stock cancelled for employee minimum income taxes (in shares)		(22,176)
Restricted stock cancelled for employee minimum income taxes	(527)	$ 0	(527)
Ending balance (in shares) at Jun. 30, 2018		14,002,999.000
Ending balance at Jun. 30, 2018	33,921	$ 140	951,349	(899,213)	(19,634)	1,279
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(29,535)			(29,982)		447
Translation adjustment	50				30	20
Stock-based compensation expense	2,831		2,831
Exercise of stock options (in shares)		24,500
Exercise of stock options	77	$ 1	76
Vesting of restricted stock units/ awards (in shares)		201,631
Vesting of restricted stock units/awards	0	$ 2	(2)
Restricted stock cancelled for employee minimum income taxes (in shares)		(70,185)
Restricted stock cancelled for employee minimum income taxes	(628)	$ (1)	(627)
Ending balance (in shares) at Jun. 30, 2019		14,171,561
Ending balance at Jun. 30, 2019	(19,381)	$ 142	954,904	(956,074)	(20,412)	2,059
Beginning balance (in shares) at Mar. 31, 2019		14,069,520
Beginning balance at Mar. 31, 2019	(11,439)	$ 141	953,679	(947,452)	(19,472)	1,665
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(8,287)			(8,622)		335
Translation adjustment	(881)				(940)	59
Stock-based compensation expense	1,538		1,538
Exercise of stock options (in shares)		18,750
Exercise of stock options	59	$ 1	58
Vesting of restricted stock units/ awards (in shares)		133,432
Vesting of restricted stock units/awards	0	$ 1	(1)
Restricted stock cancelled for employee minimum income taxes (in shares)		(50,141)
Restricted stock cancelled for employee minimum income taxes	(371)	$ (1)	(370)
Ending balance (in shares) at Jun. 30, 2019		14,171,561
Ending balance at Jun. 30, 2019	$ (19,381)	$ 142	$ 954,904	$ (956,074)	$ (20,412)	$ 2,059