Stockholders' Equity - Additional Information - Sale of Common Stock and Warrants (Detail)	Mar. 30, 2016 $ / shares $ / Warrant shares	Sep. 30, 2016 shares	Dec. 31, 2015 shares
Schedule Of Sale Of Common Stock And Warrants [Line Items]
Common stock, shares issued	861,251	15,263,322	13,973,597
Warrants issued		521,060
Common stock, stock price | $ / shares	$ 3.88
Common stock at a price per warrant | $ / Warrant	3.88
Warrants exercised period	5 years
Warrants exercise price | $ / shares	$ 3.88
Warrants To Purchase Common Stock [Member]
Schedule Of Sale Of Common Stock And Warrants [Line Items]
Warrants issued	430,628
Underwriters Warrants To Purchase Common Stock [Member]
Schedule Of Sale Of Common Stock And Warrants [Line Items]
Warrants issued	90,432