Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive (Loss) Income [Member]
Beginning balance (shares) at Dec. 31, 2017		22,419,417
Beginning balance at Dec. 31, 2017	$ 60,314	$ 224	$ 580,032	$ (520,049)	$ 107
Increase (Decrease) in Stockholders' Equity
Net loss	(5,567)			(5,567)
Foreign currency translation adjustments	(391)				(391)
Issuances of common stock:
Restricted share awards (shares)		306,385
Restricted share awards		$ 3	(3)
Restricted shares remitted by employees for taxes (shares)		(155,188)
Restricted shares remitted by employees for taxes	(1,279)	$ (2)	(1,277)
Stock option exercises (shares)		485,375
Stock option exercises	3,264	$ 5	3,259
Performance-based restricted stock unit settlement (shares)		483,623
Performance-based restricted stock unit settlement		$ 5	(5)
Restricted stock unit settlement (shares)		18,934
Forfeited restricted share awards (shares)		(87,924)
Forfeited restricted share awards	0
Stock-based compensation expense	1,462		1,462
Ending balance (shares) at Jun. 30, 2018		23,470,622
Ending balance at Jun. 30, 2018	57,803	$ 235	583,468	(525,616)	(284)
Issuances of common stock:
Restricted Stock, Value, Shares Issued Net of Tax Withholdings	0
Beginning balance (shares) at Mar. 31, 2018		23,094,617
Beginning balance at Mar. 31, 2018	59,801	$ 231	581,898	(522,710)	382
Increase (Decrease) in Stockholders' Equity
Net loss	(2,906)			(2,906)
Foreign currency translation adjustments	(666)				(666)
Issuances of common stock:
Restricted share awards (shares)		285,885
Restricted share awards		$ 3	(3)
Restricted shares remitted by employees for taxes (shares)		(20,195)
Restricted shares remitted by employees for taxes	(191)		(191)
Stock option exercises (shares)		158,303
Stock option exercises	1,004	$ 2	1,002
Restricted stock unit settlement (shares)		8,936
Forfeited restricted share awards (shares)		(56,924)
Forfeited restricted share awards		$ (1)	1
Stock-based compensation expense	761		761
Ending balance (shares) at Jun. 30, 2018		23,470,622
Ending balance at Jun. 30, 2018	57,803	$ 235	583,468	(525,616)	(284)
Issuances of common stock:
Restricted Stock, Value, Shares Issued Net of Tax Withholdings	$ 0
Beginning balance (shares) at Dec. 31, 2018	23,186,258	23,186,258
Beginning balance at Dec. 31, 2018	$ 66,329	$ 232	582,574	(515,456)	(1,021)
Increase (Decrease) in Stockholders' Equity
Net loss	(8,675)			(8,675)
Foreign currency translation adjustments	244				244
Issuances of common stock:
Restricted share awards (shares)		516,955
Restricted share awards		$ 5	(5)
Restricted shares remitted by employees for taxes (shares)		(99,885)
Restricted shares remitted by employees for taxes	(750)	$ (1)	(749)
Stock option exercises (shares)		45,380
Stock option exercises	221		221
Performance-based restricted stock unit settlement (shares)		203,524
Performance-based restricted stock unit settlement		$ 2	(2)
Restricted stock unit settlement (shares)		27,516
Forfeited restricted share awards (shares)		(24,590)
Forfeited restricted share awards	0
Repurchase of common stock (shares)		(243,755)
Repurchase of common stock	(2,228)	$ (2)	(2,226)
Stock-based compensation expense	$ 3,169		3,169
Ending balance (shares) at Jun. 30, 2019	23,611,403	23,611,403
Ending balance at Jun. 30, 2019	$ 58,310	$ 236	582,982	(524,131)	(777)
Issuances of common stock:
Restricted Stock, Value, Shares Issued Net of Tax Withholdings	0
Beginning balance (shares) at Mar. 31, 2019		23,438,058
Beginning balance at Mar. 31, 2019	61,230	$ 234	581,356	(519,852)	(508)
Increase (Decrease) in Stockholders' Equity
Net loss	(4,279)			(4,279)
Foreign currency translation adjustments	(269)				(269)
Issuances of common stock:
Restricted share awards (shares)		183,403
Restricted share awards	0	$ 2	(2)
Restricted shares remitted by employees for taxes (shares)		(38,304)
Restricted shares remitted by employees for taxes	(246)		(246)
Stock option exercises (shares)		35,319
Stock option exercises	170		170
Restricted stock unit settlement (shares)		17,517
Forfeited restricted share awards (shares)		(24,590)
Stock-based compensation expense	$ 1,704		1,704
Ending balance (shares) at Jun. 30, 2019	23,611,403	23,611,403
Ending balance at Jun. 30, 2019	$ 58,310	$ 236	$ 582,982	$ (524,131)	$ (777)
Issuances of common stock:
Restricted Stock, Value, Shares Issued Net of Tax Withholdings	$ 0