Stockholders' Equity - Additional Information - Shares Issued for Employee Stock Purchase Plan Options (Detail) - USD ($)		6 Months Ended
	May 23, 2017	Jun. 30, 2017
Schedule Of Stockholders Equity [Line Items]
Shares issued for Employee Stock Purchase Plan options, Value		$ 11,972
2014 Employee Stock Purchase Plan [Member]
Schedule Of Stockholders Equity [Line Items]
Shares issued for Employee Stock Purchase Plan options, Shares	8,749
Shares issued for Employee Stock Purchase Plan options, Value	$ 11,972