CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (DEFICIT) (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Balances at Dec. 31, 2012	$ 99,573,278	$ 35,919	$ 255,356,888	$ 72,749	$ (155,892,278)
Balances (in shares) at Dec. 31, 2012		35,919,019
Exercise of stock options	644,934	189	644,745	0	0
Exercise of stock options (in shares)	188,699	188,699
Exercise of warrants	0	48	(48)	0	0
Exercise of warrants (in shares)		47,791
Stock-based compensation	6,059,005	0	6,059,005	0	0
Stock-based compensation (in shares)		0
Net income (loss)	(18,032,438)	0	0	0	(18,032,438)
Unrealized loss on foreign exchange translation	(6,805)	0	0	(6,805)	0
Unrealized loss on securities	(9,253)	0	0	(9,253)	0
Balances at Dec. 31, 2013	88,228,721	36,156	262,060,590	56,691	(173,924,716)
Balances (in shares) at Dec. 31, 2013		36,155,509
Exercise of stock options	1,290,886	400	1,290,486	0	0
Exercise of stock options (in shares)	399,654	399,654
Stock-based compensation	8,021,447	1	8,021,446	0	0
Stock-based compensation (in shares)		1,279
Net income (loss)	5,459,477	0	0	0	5,459,477
Employee stock purchase plan	299,229	53	299,176	0	0
Employee Stock Purchase Plan (in shares)		53,250
Issuance of common stock in connection with secondary offering	101,904,977	5,175	101,899,802	0	0
Issuance of common stock in connection with secondary offering (in shares)		5,175,000
Unrealized loss on foreign exchange translation	(38,776)	0	0	(38,776)	0
Unrealized loss on securities	(161,843)	0	0	(161,843)	0
Balances at Dec. 31, 2014	$ 205,004,118	$ 41,785	$ 373,571,500	$ (143,928)	$ (168,465,239)
Balances (in shares) at Dec. 31, 2014		41,784,692