Statement of Stockholders' Equity (USD $)	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2008	$ 42,050	$ 300,892,957	$ (205,999)	$ (295,958,327)	$ 0	$ 4,770,681
Shares, issued, beginning balance at Dec. 31, 2008	42,049,792
Issuance of common stock and warrants	7,475	31,050,602				31,058,077
Issuance of common stock and warrants	7,475,000
Share-based compensation	107	4,229,076				4,229,183
Share-based compensation	106,756
Reclass of warrants to liability		(5,054,591)				(5,054,591)
Issuance of stock under purchase plan	33	123,473				123,506
Issuance of stock under purchase plan	32,142
Exercise of stock warrants	620	0				620
Exercise of stock warrants	620,582
Exercise of stock options	5	8,319				8,324
Exercise of stock options	5,138
Grant of restricted shares, net of forfeitures	(82)	82				0
Grant of restricted shares, net of forfeitures	(81,239)
Components of comprehensive loss: net loss				(27,494,457)		(27,494,457)
Comprehensive loss						(27,494,457)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2009	50,208	331,249,918	(205,999)	(323,452,784)	0	7,641,343
Shares, issued, ending balance at Dec. 31, 2009	50,208,171
Issuance of common stock and warrants	4,892	20,032,614				20,037,506
Issuance of common stock and warrants	4,891,582
Share-based compensation		2,049,606				2,049,606
Issuance of stock under purchase plan	55	209,723				209,778
Issuance of stock under purchase plan	54,762
Exercise of stock options	131	460,369				460,500
Exercise of stock options	130,555
Grant of restricted shares, net of forfeitures	(540)	540				0
Grant of restricted shares, net of forfeitures	(538,830)
Components of comprehensive loss: net loss				(19,923,487)		(19,923,487)
Comprehensive loss						(19,923,487)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2010	54,746	354,002,770	(205,999)	(343,376,271)	0	10,475,246
Shares, issued, ending balance at Dec. 31, 2010	54,746,240
Issuance of common stock and warrants	84	(84)				0
Issuance of common stock and warrants	84,000
Share-based compensation		2,487,441				2,487,441
Issuance of stock under purchase plan	85	232,306				232,391
Issuance of stock under purchase plan	84,491
Exercise of stock options	5	7,197				7,202
Exercise of stock options	4,682
Grant of restricted shares, net of forfeitures	512	(512)				0
Grant of restricted shares, net of forfeitures	512,160
Components of comprehensive loss: net loss				(32,031,175)		(32,031,175)
Comprehensive loss						(32,031,175)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2011	$ 55,432	$ 356,729,118	$ (205,999)	$ (375,407,446)	$ 0	$ (18,828,895)
Shares, issued, ending balance at Dec. 31, 2011	55,431,573