Condensed Consolidated Statement of Stockholders' Equity - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Series A Preferred Stock [Member]
Beginning Balance at Dec. 31, 2017	$ 8,877	$ 56	$ 313,922	$ (47)	$ (305,056)	$ 2
Beginning Balance, shares at Dec. 31, 2017		55,904,072				2,093,155
Stock-based compensation	2,921		2,921
Stock option exercise	$ 130		130
Stock option exercise, shares	63,295	63,295
Restricted stock awards		$ 1	(1)
Restricted stock awards, shares		1,038,957
Common stock issuance upon retirement		$ 2	(2)
Common stock issuance upon retirement, shares		1,640,198
Cumulative effect of accounting change	$ 135				135
Net loss	(10,709)				(10,709)
Ending Balance at Mar. 31, 2018	$ 1,354	$ 59	$ 316,970	$ (47)	$ (315,630)	$ 2
Ending Balance, shares at Mar. 31, 2018		58,646,522				2,093,155