Stock Options, Stock Purchase Plan and Warrants - Roll Forward of Non-Vested Stock Options Activity (Detail)	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options, Non-vested, Beginning balance | shares	1,627,718
Number of Options, Granted | shares	1,765,500
Number of Options, Vested | shares	(667,497)
Number of Options, Forfeited | shares	(7,500)
Number of Options, Non-vested, Ending balance | shares	2,718,221
Weighted average grant date fair value, Non-vested, Beginning balance | $ / shares	$ 1.35
Weighted average grant date fair value, Granted | $ / shares	2.55
Weighted average grant date fair value, Vested | $ / shares	0.57
Weighted average grant date fair value, Forfeited | $ / shares	1.39
Weighted average grant date fair value, Non-vested, Ending balance | $ / shares	$ 2.22