Consolidated Statements of Stockholders' Equity - USD ($)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]
Balance at Dec. 31, 2012	$ 34,267,498	$ 810,655	$ 782,837,507	$ (891,274)	$ (748,504,549)	$ 15,159
Balance, shares at Dec. 31, 2012		81,065,488
Other issuances of common stock	20,880,756	$ 60,164	20,820,592
Other issuances of common stock, shares		6,191,513
Repurchase of Company common stock (see Note 2(i))	(632,755)			(632,755)
Recognition of employee stock-based compensation	2,651,152		2,651,152
Non-employee stock-based compensation expense, including mark-to-market	351,089		351,089
Other comprehensive gain (loss)	(22,143)					(22,143)
Net loss	(12,322,012)				(12,322,012)
Balance at Dec. 31, 2013	45,173,585	$ 870,819	806,660,340	(1,524,029)	(760,826,561)	(6,984)
Balance, shares at Dec. 31, 2013		87,081,862
Repurchase of Company common stock, shares (see Note 2(i))		(175,139)
Other issuances of common stock	282,799	$ 1,718	281,081
Other issuances of common stock, shares		171,795
Recognition of employee stock-based compensation	3,140,855		3,140,855
Non-employee stock-based compensation expense, including mark-to-market	(80,866)		(80,866)
Other comprehensive gain (loss)	(4,013)					(4,013)
Net loss	(18,728,734)				(18,728,734)
Balance at Dec. 31, 2014	$ 29,783,626	$ 872,537	810,001,410	(1,524,029)	(779,555,295)	(10,997)
Balance, shares at Dec. 31, 2014	87,253,657	87,253,657
Issuances of common pursuant to sales of shares in the Company's public offering, in issuance costs	$ 64,619,407	$ 250,909	64,368,498
Issuances of common pursuant to sales of shares in the Company's public offering, in issuance costs,Shares		25,090,908
Issuance of common stock in consideration for rights granted under the Aurigene collaboration agreement (see Note 3(b))	23,968,183	$ 171,201	23,796,982
Issuance of common stock in consideration for rights granted under the Aurigene collaboration agreement , shares (see Note 3(b))		17,120,131
Other issuances of common stock	1,206,282	$ 7,485	1,198,797
Other issuances of common stock, shares		748,528
Recognition of employee stock-based compensation	3,582,254		3,582,254
Non-employee stock-based compensation expense, including mark-to-market	292,992		292,992
Other comprehensive gain (loss)	38,764					38,764
Net loss	(58,981,030)				(58,981,030)
Balance at Dec. 31, 2015	$ 64,510,478	$ 1,302,132	$ 903,240,933	$ (1,524,029)	$ (838,536,325)	$ 27,767
Balance, shares at Dec. 31, 2015	130,213,224	130,213,224