Consolidated Statements of Stockholders' Equity (USD $)	Total	Preferred Stock [Member]	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]
Balance at Dec. 31, 2011	$ 2,531,743	$ 3,350,000	$ 122,376	$ (8,034,244)	$ 385,879,634	$ (378,786,023)
Balance (in shares) at Dec. 31, 2011		3,350,000	12,158,099
Issuance of common stock for options exercised	1,999	0	11	0	1,988	0
Issuance of common stock for options exercised (in shares)		0	1,136
Conversion of preferred stock into common stock	0	(3,350,000)	15,227	0	3,334,773	0
Conversion of preferred stock into common stock (in shares)		(3,350,000)	1,522,727
Issuance of common stock pursuant to financing agreements	10,055,801	0	88,214	0	9,967,587	0
Issuance of common stock pursuant to financing agreements (in shares)		0	8,821,431
Stock-based compensation expense, net of forfeitures	978,243	0	0	0	978,243	0
Fair value of warrants issued pursuant to the 2012 Financing (Note 6)	2,155,527	0	0	0	2,155,527	0
Fair value of beneficial conversion of notes pursuant to the 2012 Financing (Note 6)	7,057,153	0	0	0	7,057,153	0
Net loss	(14,545,224)	0	0	0	0	(14,545,224)
Balance at Dec. 31, 2012	8,235,242	0	225,828	(8,034,244)	409,374,905	(393,331,247)
Balance (in shares) at Dec. 31, 2012		0	22,503,393
Issuance of common stock for options exercised	7,190	0	38	0	7,152	0
Issuance of common stock for options exercised (in shares)		0	3,817
Issuance of common stock for warrants exercised	52,347	0	374	0	51,973	0
Issuance of common stock for warrants exercised (in shares)			37,391
Issuance of common stock pursuant to financing agreements	6,652,255	0	44,958	0	6,607,297	0
Issuance of common stock pursuant to financing agreements (in shares)		0	4,495,828
Stock-based compensation expense, net of forfeitures	2,044,382	0	0	0	2,044,382	0
Fair value of warrants issued pursuant to the 2012 Financing (Note 6)	3,689,330	0	0	0	3,689,330	0
Net loss	(5,738,361)	0	0	0	0	(5,738,361)
Balance at Dec. 31, 2013	$ 14,942,385	$ 0	$ 271,198	$ (8,034,244)	$ 421,775,039	$ (399,069,608)
Balance (in shares) at Dec. 31, 2013		0	27,040,429