Convertible Preferred Stock - Additional Information (Detail) - shares
1 Months Ended 12 Months Ended
Feb. 05, 2014
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Equity [Abstract]        
Convertible Preferred stock, shares issued 29,186,929 0 0 0
Convertible Preferred stock, shares outstanding 29,186,929 0 0 0
Conversion of stock, shares issued 12,554,171      
IPO closing date   Feb. 05, 2014