Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Total stockholders' equity, beginning balance at Dec. 31, 2013	$ 63,790	$ 270	$ 1,281,883	$ (1,208,337)	$ (10,412)	$ 386
Total stockholders' equity, beginning balance (shares) at Dec. 31, 2013		7,286
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and warrants	1,641		1,641
Exercise of stock options and warrants (shares)		100
Share-based compensation	959		959
Net loss	(12,155)			(12,155)
Other comprehensive (loss)	(3,265)					(3,265)
Total stockholders' equity, ending balance at Dec. 31, 2014	50,970	$ 270	1,284,483	(1,220,492)	(10,412)	(2,879)
Total stockholders' equity, ending balance (shares) at Dec. 31, 2014		7,386
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Purchase of treasury shares	(4,943)				(4,943)
Purchase of treasury shares (shares)		(502)
Exercise of stock options and warrants	140		140
Exercise of stock options and warrants (shares)		98
Share-based compensation	1,164		1,164
Net loss	(7,179)			(7,179)
Other comprehensive (loss)	1,294					1,294
Total stockholders' equity, ending balance at Dec. 31, 2015	$ 41,446	$ 270	1,285,787	(1,227,671)	(15,355)	(1,585)
Total stockholders' equity, ending balance (shares) at Dec. 31, 2015	6,982	6,982
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Purchase of treasury shares	$ (2,743)				(2,743)
Purchase of treasury shares (shares)		(264)
Exercise of stock options and warrants	45		45
Exercise of stock options and warrants (shares)		84
Share-based compensation	1,504		1,504
Net loss	(11,637)			(11,637)
Other comprehensive (loss)	84					84
Total stockholders' equity, ending balance at Dec. 31, 2016	$ 28,699	$ 270	$ 1,287,336	$ (1,239,308)	$ (18,098)	$ (1,501)
Total stockholders' equity, ending balance (shares) at Dec. 31, 2016	6,802	6,802