Net Loss per Common Share - Computation of Basic and Diluted Net Loss per Common Share (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic and diluted net loss per common share:
Net loss	$ (10,640,376)	$ (4,805,559)
Weighted average common shares outstanding, basic and diluted	33,052,468	25,501,188
Net loss per common share, basic and diluted	$ (0.32)	$ (0.19)