Liquidity Risks and Management's Plans (Details) (USD $)	12 Months Ended					12 Months Ended		0 Months Ended	3 Months Ended	12 Months Ended			0 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	0 Months Ended						13 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Mar. 01, 2013	Dec. 31, 2009	Dec. 31, 2012 Deerfield Management Company [Member]	Dec. 31, 2012 Fifteen Month Warrants [Member]	Feb. 22, 2011 Five Year Warrant [Member]	Mar. 31, 2012 Five Year Warrant [Member]	Dec. 31, 2012 Five Year Warrant [Member]	Dec. 31, 2012 Minimum [Member] Five Year Warrant [Member]	Dec. 31, 2012 Maximum [Member] Five Year Warrant [Member]	Mar. 12, 2012 ATM Program [Member]	Mar. 31, 2012 ATM Program [Member]	Dec. 31, 2012 ATM Program [Member]	Mar. 31, 2012 Registered Public Offerings [Member]	Nov. 08, 2011 June 2010 CEFF [Member]	Oct. 24, 2011 June 2010 CEFF [Member]	Oct. 10, 2011 June 2010 CEFF [Member]	Jan. 24, 2011 June 2010 CEFF [Member]	Nov. 04, 2010 June 2010 CEFF [Member]	Oct. 04, 2010 June 2010 CEFF [Member]	Nov. 08, 2011 June 2010 CEFF [Member]	Dec. 31, 2012 June 2010 CEFF [Member]	Dec. 31, 2011 June 2010 CEFF [Member]	Jun. 11, 2010 June 2010 CEFF [Member]
Liquidity Risks and Management's Plans [Abstract]
Cash and cash equivalents	$ 26,892,000	$ 10,189,000	$ 10,211,000		$ 15,741,000
Stockholders' Equity [Line Items]
Common stock issued during the period (in shares)													350,374	350,374		16,071,429	129,000	37,000	35,000	314,000	166,000	351,000	1,032,000
Gross proceeds														1,600,000	25,000,000		218,000	63,000	69,000	991,000	432,000	973,000	2,746,000
Percentage of gross proceeds															3.00%
Net proceeds from issuance of stock													1,500,000	1,500,000		42,100,000
Value of potential common stock available for issue																								2,500,000
Class of Warrant or Right [Line Items]
Exercisable period of warrants							15 months	5 years		5 years
Exercise of warrants to purchase common stock (in shares)						4,700,000	2,238,000		51,250	51,250
Exercise of warrants to purchase common stock upon execution (in shares)						2,340,000
Additional Exercise of warrants to purchase common stock (in shares)						4,660,000
Amount to be raised incase of exercise of warrants						19,700,000
Exercise price of warrants (in dollars per share)						$ 2.81	$ 2.94	$ 2.80			$ 2.80	$ 3.20
Number of Warrant Shares Issuable (in shares)	8,000,000							4,948,750		4,948,750
Proceeds from exercise of warrants	6,741,000	0	0				6,600,000		162,000	162,000
Number of securities called by warrant expired (in shares)							2,762,000
Potential value of common stock issuable upon exercise of warrants, maximum										13,900,000
Proceeds from secured loan						30,000,000
Proceeds from secured loan upon execution of the agreement						10,000,000
Additional Proceeds from secured loan						$ 20,000,000
Percentage of amount disbursed (in hundredths)						1.50%
Outstanding principal rate (in hundredths)						8.75%
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock reserved for future issuance (in shares)	40,300,000																							1,074,114	1,074,114	2,100,000
Closing market price (in dollars per share)				$ 2.44
Period to sell common stock under ATM Program	3 years