Net Loss per Share - Reconciliation of Numerator and Denominator Used in Computing Basic and Diluted Net Loss per Share (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator:
Net loss	$ (5,816,274)	$ (7,026,424)
Denominator:
Weighted-average shares outstanding-basic and diluted	7,971,097	6,885,522
Net loss per share, basic and diluted	$ (0.73)	$ (1.02)