v3.6.0.2
Capitalization - Initial Public Offering (Detail)
$ / shares in Units, $ in Thousands
 12 Months Ended
Sep. 26, 2016
USD ($)
$ / shares
shares
Sep. 02, 2016
Dec. 31, 2016
USD ($)
Class of Stock [Line Items]      
Net proceeds from the offering | $     $ 78,120
Reverse stock split ratio   0.3333  
Convertible Preferred Stock Warrants      
Class of Stock [Line Items]      
Outstanding warrants converted during the period (in shares) 1,382,505    
Class B Common Stock Warrants      
Class of Stock [Line Items]      
Warrants issued in conversion (in shares) 460,834    
Stock issued in net exercise of warrants (in shares) 448,545    
IPO      
Class of Stock [Line Items]      
IPO price (in dollars per share) | $ / shares $ 18.00    
Net proceeds from the offering | $ $ 78,100    
Underwriting commissions and discounts | $ 5,900    
Offering costs reclassified from other assets to additional paid-in capital | $ $ 4,500    
Class A common stock | IPO      
Class of Stock [Line Items]      
Number of shares issued and sold by the Company 4,666,667    
Number of shares sold by selling shareholders 700,000    
Class B common stock      
Class of Stock [Line Items]      
Stock issued in net exercise of warrants (in shares) 448,545    
Number of shares issued for automatic conversion of convertible preferred stock 22,078,637    
Number of common stock shares issued for each share of convertible preferred stock 0.3333