Stockholders' Equity - Additional Information - Shares Issued for Employee Stock Purchase Plan Options (Detail) - USD ($)			12 Months Ended
	Nov. 15, 2015	May. 15, 2015	Dec. 31, 2015
Schedule Of Stockholders Equity [Line Items]
Shares issued for Employee Stock Purchase Plan options, Shares			130,421
Shares issued for Employee Stock Purchase Plan options, Value			$ 110,066
2014 Employee Stock Purchase Plan [Member]
Schedule Of Stockholders Equity [Line Items]
Shares issued for Employee Stock Purchase Plan options, Shares	73,287	57,134
Shares issued for Employee Stock Purchase Plan options, Value	$ 49,361	$ 60,705