Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Nil Coupon Perpetual Loan Notes	Treasury Stock
Balance (in shares) at Dec. 31, 2015		23,167,000
Balance at Dec. 31, 2015	$ 58,271	$ 234	$ 135,394	$ (74,835)	$ (1,556)	$ 76	$ (1,042)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(17,388)			(17,388)
Correction of error (Note 1)	(703)			(703)
Foreign currency translation adjustments	(6)				(6)
Unrealized losses from marketable securities, net of tax	(6)				(6)
Stock compensation expense	1,991		1,991
Common shares issued upon vesting of restricted stock units (in shares)		382,000
Common shares issued upon vesting of restricted stock units	(1)	$ 4	(5)
Treasury shares withheld (in shares)		(103,000)
Treasury shares withheld	(172)						(172)
Balance (in shares) at Dec. 31, 2016		23,446,000
Balance at Dec. 31, 2016	42,689	$ 238	137,380	(92,223)	(1,568)	76	(1,214)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(10,449)			(10,449)
Foreign currency translation adjustments	802				802
Unrealized losses from marketable securities, net of tax	(2)				(2)
Stock compensation expense	1,389		1,389
Common shares issued upon vesting of restricted stock units (in shares)		976,000
Common shares issued upon vesting of restricted stock units	$ 1	$ 10	(9)
Treasury shares withheld (in shares)	(289,202)	(289,000)
Treasury shares withheld	$ (258)						(258)
Balance (in shares) at Dec. 31, 2017		24,133,000
Balance at Dec. 31, 2017	34,172	$ 248	138,760	(102,672)	(768)	76	(1,472)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(28)
Foreign currency translation adjustments	(513)
Unrealized losses from marketable securities, net of tax	(4)
Stock compensation expense	233		233
Common shares issued upon vesting of restricted stock units (in shares)		49,000
Common shares issued upon vesting of restricted stock units	$ (1)	$ 0	(1)
Treasury shares withheld (in shares)	(11,215)	(12,000)
Treasury shares withheld	$ (12)						(12)
Adoption of ASC 606	205
Balance (in shares) at Dec. 31, 2018		24,170,000
Balance at Dec. 31, 2018	$ 34,052	$ 248	$ 138,992	$ (102,495)	$ (1,285)	$ 76	$ (1,484)