Net Loss Per Share - Basic and Diluted Loss Per Common Share (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net loss	$ (7,186,441)	$ (6,359,957)	$ (25,078,771)	$ (14,871,661)
Basic and diluted weighted average common shares outstanding	130,771,380	127,162,064	130,163,929	126,581,018
Basic and diluted net loss per common share	$ (0.05)	$ (0.05)	$ (0.19)	$ (0.12)