Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - 3 months ended Mar. 31, 2016 - 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, 2015	$ 31,696	$ 53	$ 274,891	$ (47)	$ (243,203)	$ 2
Beginning Balance, shares at Dec. 31, 2015		52,730,799				2,093,155
Stock-based compensation	4,111		4,111
Exercise of stock options	$ 225		225
Exercise of stock options, shares	112,425	112,425
Restricted stock awards	$ 0	$ 0	0	0	0	$ 0
Restricted stock awards, shares		104,025
Common stock issuance upon retirement	2,460	$ 1	2,459
Common stock issuance upon retirement, shares		663,221
Equity financing costs	40		40
Net loss	(18,733)				(18,733)
Ending Balance at Mar. 31, 2016	$ 19,799	$ 54	$ 281,726	$ (47)	$ (261,936)	$ 2
Ending Balance, shares at Mar. 31, 2016		53,610,470				2,093,155