Statement of Stockholders’ Equity - 6 months ended Jun. 30, 2016 - USD ($)	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Dec. 31, 2015	$ 50,802	$ 325,784,484	$ (182,497,965)	$ (205,856)	$ 143,131,465
Balance (in shares) at Dec. 31, 2015	50,802,603				50,802,603
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense		2,713,109			$ 2,713,109
Exercise of stock options	$ 25	61,283			$ 61,308
Exercise of stock options (in shares)	23,618				23,618
Net exercise of common stock warrant (in shares)	698
Issuance of common stock, net of issuance costs	$ 1,351	11,791,047			$ 11,792,398
Issuance of common stock, net of issuance costs (in shares)	1,350,755
Unrealized gains on marketable securities				280,973	280,973
Net loss			(36,995,297)		(36,995,297)
Balance at Jun. 30, 2016	$ 52,178	$ 340,349,923	$ (219,493,262)	$ 75,117	$ 120,983,956
Balance (in shares) at Jun. 30, 2016	52,177,674				52,177,674