Statement of Stockholders' Equity (USD $)	Common Stock [Member]	Additional Paid In Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Total
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2009	$ 5,021	$ 331,295,105	$ (205,999)	$ (323,452,784)	$ 7,641,343
Shares, issued, beginning balance at Dec. 31, 2009	5,020,817
Issuance of common stock and warrants, value	489	20,037,017			20,037,506
Issuance of common stock and warrants, shares	489,158
Share-based compensation, value		2,049,606			2,049,606
Issuance of stock under purchase plan, value	6	209,772			209,778
Issuance of stock under purchase plan, shares	5,476
Exercise of stock options, value	13	460,487			460,500
Exercise of stock options, shares	13,056
Grant of restricted shares, net of forfeitures, value	(54)	54
Grant of restricted shares, net of forfeitures, shares	(53,883)
Net Loss				(19,923,487)	(19,923,487)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2010	5,475	354,052,041	(205,999)	(343,376,271)	10,475,246
Shares, issued, ending balance at Dec. 31, 2010	5,474,624
Issuance of common stock and warrants, value	8	(8)
Issuance of common stock and warrants, shares	8,400
Share-based compensation, value		2,487,441			2,487,441
Issuance of stock under purchase plan, value	9	232,382			232,391
Issuance of stock under purchase plan, shares	8,449
Exercise of stock options, value		7,202			7,202
Exercise of stock options, shares	468
Grant of restricted shares, net of forfeitures, value	51	(51)
Grant of restricted shares, net of forfeitures, shares	51,216
Net Loss				(32,031,175)	(32,031,175)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2011	5,543	356,779,007	(205,999)	(375,407,446)	(18,828,895)
Shares, issued, ending balance at Dec. 31, 2011	5,543,157
Issuance of common stock and warrants, value	2,415	10,409,260			10,411,675
Issuance of common stock and warrants, shares	2,415,339
Share-based compensation, value		2,293,731			2,293,731
Issuance of stock under purchase plan, value	10	73,543			73,553
Issuance of stock under purchase plan, shares	10,315
Exercise of stock options, value					0
Exercise of stock options, shares					0
Grant of restricted shares, net of forfeitures, value	20	(20)
Grant of restricted shares, net of forfeitures, shares	19,885
Restricted stock vestings, value	31	(31)
Restricted stock vestings, shares	29,919
Reclass of warrants to liability		(3,501,863)			(3,501,863)
Net Loss				(9,238,427)	(9,238,427)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2012	$ 8,019	$ 366,053,627	$ (205,999)	$ (384,645,873)	$ (18,790,226)
Shares, issued, ending balance at Dec. 31, 2012	8,018,615