Statements of Stockholders' Equity (Deficit) (USD $)	Total USD ($)	Common Stock [Member] USD ($)	Preferred Stock [Member]	Additional Paid-In Capital [Member] USD ($)	Accumulated Deficit [Member] USD ($)
Beginning Balance at Dec. 31, 2010	$ (5,255,000)	$ 5,000		$ 202,440,000	$ (207,700,000)
Beginning Balance, shares at Dec. 31, 2010		458,000
Net loss and comprehensive loss	(9,653,000)				(9,653,000)
Issuance of common stock in connection with the private placement warrant exchange	5,383,000	1,000		5,382,000
Issuance of common stock in connection with the private placement warrant exchange, shares		130,000
Issuance of common stock under ATM, net of expenses of $1,013, $137 and $72 in 2011, 2012 and 2013 respectively	17,146,000	7,000		17,139,000
Issuance of common stock under ATM, net of expenses of $1,013, $137 and $72 in 2011, 2012 and 2013 respectively, shares		650,000
Issuance of common stock for the initial commitment fee in connection with the LPC purchase agreement	314,000			314,000
Issuance of common stock for the initial commitment fee in connection with the LPC purchase agreement, shares		25,000
Issuance of common stock under employee stock purchase plan	8,000			8,000
Reclassification of CEFF warrants to equity from derivative liability due to warrant exchange	3,000			3,000
Stock based compensation expense	851,000			851,000
Stock based compensation expense, shares		2,000
Ending Balance at Dec. 31, 2011	8,797,000	13,000		226,137,000	(217,353,000)
Ending Balance, shares at Dec. 31, 2011		1,265,000
Net loss and comprehensive loss	(8,079,000)				(8,079,000)
Issuance of common stock under ATM, net of expenses of $1,013, $137 and $72 in 2011, 2012 and 2013 respectively	1,270,000	1,000		1,269,000
Issuance of common stock under ATM, net of expenses of $1,013, $137 and $72 in 2011, 2012 and 2013 respectively, shares		178,000
Issuance of common stock to LPC, net of expenses of $552/ Issuance of preferred stock in connection with the private placement, net of expenses of $1,703	2,047,000	3,000		2,044,000
Issuance of common stock to LPC, net of expenses of $552, shares/ Issuance of preferred stock in connection with the private placement, net of expenses of $1,703, shares		294,000
Additional shares due to reverse stock split, shares		7,000
Stock based compensation expense	511,000			511,000
Stock based compensation expense, shares		2,000
Ending Balance at Dec. 31, 2012	4,546,000	17,000		229,961,000	(225,432,000)
Ending Balance, shares at Dec. 31, 2012		1,746,000
Net loss and comprehensive loss	(8,277,000)				(8,277,000)
Issuance of common stock under ATM, net of expenses of $1,013, $137 and $72 in 2011, 2012 and 2013 respectively	1,936,000	4,000		1,932,000
Issuance of common stock under ATM, net of expenses of $1,013, $137 and $72 in 2011, 2012 and 2013 respectively, shares		422,000
Issuance of common stock to LPC, net of expenses of $552/ Issuance of preferred stock in connection with the private placement, net of expenses of $1,703	9,097,000			9,097,000
Issuance of common stock to LPC, net of expenses of $552, shares/ Issuance of preferred stock in connection with the private placement, net of expenses of $1,703, shares			11,000
Redemption of preferred stock in connection with the private placement	(2,802,000)			(2,802,000)
Redemption of preferred stock in connection with the private placement, shares			(3,000)
Non-cash deemed dividend to preferred stock in connection with the private placement				4,799,000	(4,799,000)
Conversion of preferred stock to common stock		31,000		(31,000)
Conversion of preferred stock to common stock, shares		3,058,000	(8,000)
Issuance of common stock in connection with the exercise of Series B warrants, net of expenses of $55	864,000	3,000		861,000
Issuance of common stock in connection with the exercise of Series B warrants, net of expenses of $55, shares		270,000
Stock based compensation expense	679,000	1,000		678,000
Stock based compensation expense, shares		90,000
Ending Balance at Dec. 31, 2013	$ 6,043,000	$ 56,000		$ 244,495,000	$ (238,508,000)
Ending Balance, shares at Dec. 31, 2013		5,586,000