Determination of Net Loss Per Common Share (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Determination of net loss per common share [Line Items]
Net loss	$ (9,187,348)	$ (7,766,222)	$ (8,019,137)
Deemed dividend attributable to preferred stockholders in connection with beneficial conversion features	(4,140,446)	(2,955,668)	(766,872)
Deemed dividend attributable to preferred stockholders in connection with preferred stock modifications	(8,332,212)	0	0
Return of capital to common shareholders attributable to the repurchase of preferred shares and related embedded beneficial conversion feature	589,751	0	0
Net loss applicable to common stockholders	$ (21,070,255)	$ (10,721,890)	$ (8,786,009)
Net loss per common share applicable to common stockholders, basic and diluted	$ (7.75)	$ (6.15)	$ (12.28)
Weighted average number of common shares outstanding, basic and diluted	2,719,285	1,743,494	715,524