Quarterly report pursuant to Section 13 or 15(d)

Redeemable Convertible Preferred Stock - Additional Information (Detail)

v3.8.0.1
Redeemable Convertible Preferred Stock - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended
May 17, 2017
Sep. 30, 2017
Mar. 31, 2017
Sep. 30, 2017
May 31, 2017
Apr. 30, 2017
Dec. 31, 2016
Class of Stock [Line Items]              
Net book value             $ 23,350
Preferred Stock, authorized         1,000,000 11,500,000  
Preferred Stock, par value           $ 0.001  
Series B Redeemable Convertible Preferred Stock [Member]              
Class of Stock [Line Items]              
Liquidation preference value $ 18,668            
Net book value $ 18,463           $ 17,897
Shares converted to common stock 2,309,135     2,309,135      
Change in liquidation preference and net book value $ 205            
Debt beneficial conversion feature     $ 226        
Debt amortization of discount   $ 10   $ 67      
Write-off of unamortized portion of beneficial conversion feature       $ 159      
Preferred Stock, authorized   0   0     3,092,781
Preferred Stock, par value   $ 0.001   $ 0.001     $ 0.001
Series A Redeemable Convertible Preferred Stock [Member]              
Class of Stock [Line Items]              
Liquidation preference value 8,598            
Net book value $ 6,272           $ 5,453
Shares converted to common stock 2,922,798     2,922,798      
Change in liquidation preference and net book value $ 2,326            
Debt beneficial conversion feature     $ 328        
Debt amortization of discount   $ 14   $ 96      
Write-off of unamortized portion of beneficial conversion feature       $ 232      
Preferred Stock, authorized   0   0     5,666,667
Preferred Stock, par value   $ 0.001   $ 0.001     $ 0.001