Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Deficit) - Schedule of Stock Option Activity (Detail)

v3.7.0.1
Stockholders' Equity (Deficit) - Schedule of Stock Option Activity (Detail)
$ / shares in Units, $ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2017
USD ($)
$ / shares
shares
Dec. 31, 2016
USD ($)
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Options Exercised (1,580)  
2014 Stock Option/Stock Issuance Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Options, Outstanding, Beginning Balance 680,434  
Options Granted 3,801,158  
Options Exercised (1,580)  
Options Forfeited / Cancelled (48,905)  
Options, Outstanding, Ending Balance 4,431,107 680,434
Options, Exercisable at June 30, 2017 350,716  
Weighted-Average Exercise Price, Outstanding, Beginning Balance | $ / shares $ 2.27  
Weighted-Average Exercise Price, Options Granted | $ / shares 15.00  
Weighted-Average Exercise Price, Options Exercised | $ / shares 1.93  
Weighted-Average Exercise Price, Options Forfeited / Cancelled | $ / shares 2.88  
Weighted-Average Exercise Price, Outstanding, Ending Balance | $ / shares $ 13.17 $ 2.27
Weighted-Average Remaining Contractual Term, Outstanding 8 years 3 months 29 days 8 years 5 months 27 days
Weighted-Average Aggregate Intrinsic Value | $ $ 5,972 $ 3,031