XML 85 R68.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock-based compensation - Summary of Performance-based and Market-based Stock Option Activity and Related Information (Details)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
USD ($)
$ / shares
shares
Weighted-average exercise price  
Options outstanding, Exercisable (in shares) | shares 1,068,482
Weighted-average exercise price, Exercisable (in USD per share) $ 2.00
Weighted-average remaining contractual life (in years), Exercisable 5 years 8 months 12 days
Aggregate intrinsic values, Exercisable | $ $ 7,120
Closing stock price (in USD per share) $ 8.66
Performance-based and Market-based Stock Options  
Options outstanding  
Beginning balance (in shares) | shares 2,406,537
Exercised (in shares) | shares (901,505)
Canceled or forfeited (in shares) | shares (22,250)
Ending balance (in shares) | shares 1,482,782
Weighted-average exercise price  
Beginning balance (in USD per share) $ 6.58
Exercised (in USD per share) 2.54
Canceled or forfeited (in USD per share) 12.95
Ending balance (in USD per share) $ 8.94
Weighted-average remaining contractual life (in years), Outstanding 6 years 3 months 18 days
Aggregate intrinsic values, Outstanding | $ $ 7,120