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, 2014		22,860,000
Balance at Dec. 31, 2014	$ 72,301	$ 230	$ 134,985	$ (61,752)	$ (448)	$ 76	$ (790)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)	(12,380)			(12,380)
Foreign currency translation adjustments	(1,097)				(1,097)
Unrealized (losses)/gains from marketable securities, net of tax	(11)				(11)
Stock compensation expense	1,809		1,809
Issuance of Deferred Director's shares (in shares)		39,000
Issuance of Deferred Director's shares	(70)	$ 1	(71)
Tax effect of expired vested options	(908)		(908)
Common shares issued upon vesting of restricted stock units (in shares)		352,000
Common shares issued upon vesting of restricted stock units	(418)	$ 3	(421)
Treasury shares withheld (in shares)		(84,000)
Treasury shares withheld	(252)						(252)
Balance (in shares) at Dec. 31, 2015		23,167,000
Balance at Dec. 31, 2015	58,974	$ 234	135,394	(74,132)	(1,556)	76	(1,042)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)	(17,388)			(17,388)
Foreign currency translation adjustments	(6)				(6)
Unrealized (losses)/gains 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)	(103,097)	(103,000)
Treasury shares withheld	$ (172)						(172)
Balance (in shares) at Dec. 31, 2016		23,446,000
Balance at Dec. 31, 2016	43,392	$ 238	137,380	(91,520)	(1,568)	76	(1,214)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)	(10,983)
Foreign currency translation adjustments	802				802
Unrealized (losses)/gains 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	$ 34,341	$ 248	$ 138,760	$ (102,503)	$ (768)	$ 76	$ (1,472)