CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' DEFICIT - 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, 2018		14,015,615
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 adjustments	(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
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
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 adjustments	(1,197)				(1,028)	(169)
Stock-based compensation expense	905		905
Exercise of stock options (in shares)		58,400
Exercise of stock options	26		26
Vesting of restricted stock units/awards (in shares)		1,066
Vesting of restricted stock units/awards	0
Vested restricted stock cancelled for employee minimum income taxes (in shares)		(29,377)
Vested restricted stock cancelled for employee minimum income taxes	(130)		(130)
Ending balance (in shares) at Sep. 30, 2019		14,201,650
Ending balance at Sep. 30, 2019	(23,106)	$ 142	955,705	(959,797)	(21,440)	2,284
Beginning balance (in shares) at Dec. 31, 2019		14,224,787
Beginning balance at Dec. 31, 2019	(34,632)	$ 142	956,647	(974,291)	(19,318)	2,188
Comprehensive income (loss):
Net (loss) income	(23,921)			(24,089)		168
Translation adjustments	(2,298)				(1,694)	(604)
Dividend payment to noncontrolling interest						(217)
Stock-based compensation expense	1,637		1,637
Exercise of stock options (in shares)		5,000
Exercise of stock options	15		15
Vesting of restricted stock units/awards (in shares)		128,183
Vesting of restricted stock units/awards	0	$ 2	(2)
Vested restricted stock cancelled for employee minimum income taxes (in shares)		(42,517)
Vested restricted stock cancelled for employee minimum income taxes	(108)		(108)
Ending balance (in shares) at Sep. 30, 2020		14,315,453
Ending balance at Sep. 30, 2020	(59,524)	$ 144	958,189	(998,380)	(21,012)	1,535
Beginning balance (in shares) at Jun. 30, 2020		14,245,829
Beginning balance at Jun. 30, 2020	(44,110)	$ 142	957,746	(981,773)	(21,833)	1,608
Comprehensive income (loss):
Net (loss) income	(16,414)			(16,607)		193
Translation adjustments	772				821	(49)
Dividend payment to noncontrolling interest	(217)					(217)
Stock-based compensation expense	543		543
Exercise of stock options	0
Vesting of restricted stock units/awards (in shares)		111,094
Vesting of restricted stock units/awards	0	$ 2	(2)
Vested restricted stock cancelled for employee minimum income taxes (in shares)		(41,470)
Vested restricted stock cancelled for employee minimum income taxes	(98)		(98)
Ending balance (in shares) at Sep. 30, 2020		14,315,453
Ending balance at Sep. 30, 2020	$ (59,524)	$ 144	$ 958,189	$ (998,380)	$ (21,012)	$ 1,535