Determination of Net Loss Per Common Share (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Determination of net loss per common share [Line Items]
Net loss	$ (7,766,222)	$ (8,019,137)	$ (10,007,553)
Deemed dividend attributable to preferred stockholders in connection with beneficial conversion features	(2,955,668)	(766,872)	0
Net loss applicable to common stockholders	$ (10,721,890)	$ (8,786,009)	$ (10,007,553)
Net loss per common share applicable to common stockholders, basic and diluted	$ (1.54)	$ (3.07)	$ (5.22)
Weighted average number of common shares outstanding, basic and diluted	6,973,977	2,862,094	1,918,723