XML 52 R40.htm IDEA: XBRL DOCUMENT v3.10.0.1
STOCK-BASED COMPENSATION - Stock Options (Details) - USD ($)
$ / shares in Units, $ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Number of Shares      
Granted (in shares) 747,892    
Weighted Average Exercise Price      
Granted (in dollars per share) $ 9.99 $ 13.19  
2009 plan      
Number of Shares      
Outstanding at the beginning of the period (in shares) 3,738,928    
Granted (in shares) 1,449,690    
Exercised (in shares) (107,233)    
Forfeited (144,152)    
Outstanding at the end of the period (in shares) 4,937,233   3,738,928
Vested and expected to vest (in shares) 4,937,233    
Options exercisable (in shares) 2,414,308    
Weighted Average Exercise Price      
Outstanding at the beginning of the period (in dollars per share) $ 6.93    
Granted (in dollars per share) 13.74    
Exercised (in dollars per share) 2.71    
Forfeited (in dollars per share) 5.85    
Outstanding at the end of the period (in dollars per share) 9.04   $ 6.93
Vested and expected to vest (in dollars per share ) 9.04    
Options exercisable (in dollars per shares) $ 5.29    
Weighted Average Remaining Contractual Term      
Weighted average period 8 years 11 days   8 years 4 months 24 days
Vested and expected to vest 8 years 11 days    
Options exercisable 7 years 1 month 21 days    
Aggregate Intrinsic Value      
Outstanding at the beginning of the period (in dollars) $ 44,578    
Outstanding at the end of the period (in dollars) 16,968   $ 44,578
Vested and expected to vest (in dollars) 16,968    
Options exercisable (in dollars) $ 13,198