Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Payments - Stock Options (Details)

v3.5.0.2
Stock-Based Payments - Stock Options (Details) - USD ($)
$ / shares in Units, $ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2016
Dec. 31, 2015
Stock-based payments    
Unrecognized compensation costs $ 9,300  
Aggregate Intrinsic Value    
Intrinsic value of options exercised $ 2,300  
Stock options    
Stock-based payments    
Vesting period 4 years  
Shares    
Outstanding at beginning of year (in shares) 2,226,698  
Granted (in shares) 709,441  
Exercised (in shares) (240,515)  
Cancelled (in shares) (161,011)  
Outstanding at end of period (in shares) 2,534,613 2,226,698
Exercisable (in shares) 699,598  
Vested and expected to vest (in shares) 2,534,613  
Weighted Average Exercise Price    
Outstanding at beginning of year (in dollars per share) $ 3.83  
Granted (in dollars per share) 11.88  
Exercised (in dollars per share) 3.37  
Cancelled (in dollars per share) 1.53  
Outstanding at end of period (in dollars per share) 6.33 $ 3.83
Exercisable (in dollars per share) 2.49  
Vested and expected to vest (in dollars per share) $ 6.33  
Remaining Contractual Life    
Outstanding 8 years 7 months 6 days 8 years 9 months 18 days
Exercisable 7 years 6 months  
Vested and expected to vest 8 years 7 months 6 days  
Aggregate Intrinsic Value    
Outstanding $ 19,108 $ 11,185
Exercisable 7,963  
Vested and expected to vest 19,108  
Performance-based stock options    
Stock-based payments    
Additional stock-based compensation expense recorded related to achievement of certain performance-based milestones 200 $ 26
Unrecognized compensation costs $ 1,100  
Performance-based stock options | Maximum    
Stock-based payments    
Vesting period 6 years