Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock Issued [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning balance at Dec. 31, 2012	$ 4,785	$ 184	$ 216,667	$ (201,000)	$ (7,027)	$ (4,039)
Beginning balance, shares at Dec. 31, 2012		18,407,848
Proceeds from issuance of common stock, net	5,621	$ 15	5,606
Proceeds from issuance of Common Stock, shares		1,538,462
Issuance of common stock for option awards exercised	$ 16		16
Issuance of common stock for option awards exercised, shares	4,498	4,498
Issuance of Common Stock related to employee stock programs	$ 1,819	$ 7	1,812
Issuance of Common Stock related to employee stock programs, shares		728,761
Amortization/forfeitures of unearned compensation	4,524	$ (1)	4,525
Amortization/forfeitures of unearned compensation, shares		(213,664)
Purchase of treasury shares	(1,055)				(1,055)
Series B convertible preferred stock conversions	1		1
Series B convertible preferred stock conversions, shares		79
Series B convertible preferred stock dividend	(589)		(589)
Other comprehensive gain (loss)	6					6
Net loss	(11,172)			(11,172)
Ending balance at Dec. 31, 2013	3,956	$ 205	228,038	(212,172)	(8,082)	(4,033)
Ending balance, shares at Dec. 31, 2013		20,465,984
Proceeds from issuance of common stock, net	11,138	$ 29	11,109
Proceeds from issuance of Common Stock, shares		2,891,566
Issuance of common stock for option awards exercised	$ 14		14
Issuance of common stock for option awards exercised, shares	2,914	2,914
Issuance of Common Stock for warrants exercised	$ 529	$ 1	528
Issuance of Common Stock for warrants exercised, shares		86,366
Issuance of Common Stock related to employee stock programs	194	$ 5	189
Issuance of Common Stock related to employee stock programs, shares		643,706
Amortization/forfeitures of unearned compensation	3,988		3,988
Amortization/forfeitures of unearned compensation, shares		(44,496)
Purchase of treasury shares	(797)				(797)
Series B convertible preferred stock conversions	5		5
Series B convertible preferred stock conversions, shares		937
Series B convertible preferred stock dividend	(589)		(589)
Other comprehensive gain (loss)	7					7
Net loss	(14,232)			(14,232)
Ending balance at Dec. 31, 2014	4,213	$ 240	243,282	(226,404)	(8,879)	(4,026)
Ending balance, shares at Dec. 31, 2014		24,046,977
Proceeds from issuance of common stock, net	15,942	$ 27	15,915
Proceeds from issuance of Common Stock, shares		2,728,712
Issuance of common stock for option awards exercised	$ 282		282
Issuance of common stock for option awards exercised, shares	59,638	41,750
Issuance of Common Stock for warrants exercised	$ 378	$ 1	377
Issuance of Common Stock for warrants exercised, shares		50,184
Issuance of Common Stock related to employee stock programs	271	$ 8	263
Issuance of Common Stock related to employee stock programs, shares		819,632
Amortization/forfeitures of unearned compensation	5,178		5,178
Amortization/forfeitures of unearned compensation, shares		(53,819)
Purchase of treasury shares	(874)				(874)
Reissuance of treasury shares			(514)		514
Series B convertible preferred stock conversions	17		17
Series B convertible preferred stock conversions, shares		3,417
Series B convertible preferred stock dividend	(588)		(588)
Other comprehensive gain (loss)	(1)					(1)
Net loss	(15,681)			(15,681)
Ending balance at Dec. 31, 2015	$ 9,137	$ 276	$ 264,212	$ (242,085)	$ (9,239)	$ (4,027)
Ending balance, shares at Dec. 31, 2015		27,636,853