CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning Balance at Dec. 31, 2009	$ 21,448	$ 9,496	$ 39	$ 421,897	$ 58	$ (410,042)
Beginning Balance (in shares) at Dec. 31, 2009		3	38,678
Net loss	(16,911)	0	0	0	0	(16,911)
Other comprehensive income (loss)	50	0	0	0	50	0
Issuance of common stock from public offering, net of expenses of $550 for 2012 ,$420 for 2011 and $1,710,for 2010 (in shares)		0	8,306
Issuance of common stock from public offering, net of expenses of $550 for 2012 ,$420 for 2011 and $1,710,for 2010	16,948	0	8	16,940	0	0
Issuance of common stock from exercise of stock options and/or warrants, and purchases from ESPP(In Shares)		0	345
Issuance of common stock from exercise of stock options and/or warrants, and purchases from ESPP	369	0	0	369	0	0
Stock-based compensation	1,828	0	0	1,828	0	0
Ending Balance at Dec. 31, 2010	23,732	9,496	47	441,034	108	(426,953)
Ending Balance (in shares) at Dec. 31, 2010		3	47,329
Net loss	(16,982)	0	0	0	0	(16,982)
Other comprehensive income (loss)	(108)	0	0	0	(108)	0
Issuance of common stock from public offering, net of expenses of $550 for 2012 ,$420 for 2011 and $1,710,for 2010 (in shares)		0	3,701
Issuance of common stock from public offering, net of expenses of $550 for 2012 ,$420 for 2011 and $1,710,for 2010	9,678	0	4	9,674	0	0
Issuance of common stock from exercise of stock options and/or warrants, and purchases from ESPP(In Shares)		0	181
Issuance of common stock from exercise of stock options and/or warrants, and purchases from ESPP	143	0	0	143	0	0
Stock-based compensation	1,850	0	0	1,850	0	0
Ending Balance at Dec. 31, 2011	18,313	9,496	51	452,701	0	(443,935)
Ending Balance (in shares) at Dec. 31, 2011		3	51,211
Net loss	(15,917)	0	0	0	0	(15,917)
Issuance of common stock from public offering, net of expenses of $550 for 2012 ,$420 for 2011 and $1,710,for 2010 (in shares)		0	4,487
Issuance of common stock from public offering, net of expenses of $550 for 2012 ,$420 for 2011 and $1,710,for 2010	13,821	0	5	13,816	0	0
Issuance of common stock from exercise of stock options and/or warrants, and purchases from ESPP(In Shares)		0	221
Issuance of common stock from exercise of stock options and/or warrants, and purchases from ESPP	349	0	0	349	0	0
Preferred stock conversion (in shares)		(3)	333
Preferred stock conversion	0	(9,496)	0	9,496	0	0
Stock-based compensation	2,541	0	0	2,541	0	0
Ending Balance at Dec. 31, 2012	$ 19,107	$ 0	$ 56	$ 478,903	$ 0	$ (459,852)
Ending Balance (in shares) at Dec. 31, 2012		0	56,252