Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Summary of Stock Option Activity (Detail)

v3.7.0.1
Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
6 Months Ended 12 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]    
Number of shares, Outstanding, Beginning Balance 1,930,600  
Number of shares, Granted 2,119,699  
Number of shares, Canceled (20,825)  
Number of shares, Outstanding, Ending Balance 4,029,474 1,930,600
Number of shares, Exercisable at June 30, 2017 0  
Weighted average exercise price per share outstanding, Beginning balance $ 4.45  
Weighted average exercise price per share, Granted 13.29  
Weighted average exercise price per share, Canceled 5.85  
Weighted average exercise price per share outstanding, Ending balance $ 9.09 $ 4.45
Aggregate intrinsic value, Outstanding at June 30, 2017 $ 8,018  
Weighted average remaining contractual life, Outstanding 9 years 3 months 19 days 9 years 1 month 6 days