Condensed Statements of Comprehensive Loss - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (5,816,274)	$ (7,026,424)
Other comprehensive income, net of tax effect:
Unrealized gain on short and long-term investments	354	39,351
Comprehensive loss	$ (5,815,920)	$ (6,987,073)