Annual report pursuant to Section 13 and 15(d)

Stock Incentive Plan - Stock Options Activity (Details)

v3.10.0.1
Stock Incentive Plan - Stock Options Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Number of Options      
Beginning balance (in shares) 3,834,000 3,971,000 4,139,000
Granted (in shares) 518,000 390,000 665,000
Exercised (in shares) (909,000) (401,000) (321,000)
Forfeited (in shares) (87,000) (41,000) (194,000)
Expired (in shares) (51,000) (85,000) (318,000)
Ending balance (in shares) 3,305,000 3,834,000 3,971,000
Options exercisable (in shares) 1,926,000    
Options expected to vest (in shares) 1,379,000    
Weighted-Average Exercise Price      
Beginning balance (in usd per share) $ 7.367 $ 7.300 $ 7.740
Granted (in usd per share) 10.878 6.061 4.703
Exercised (in usd per share) 7.367 4.935 3.286
Forfeited (in usd per share) 4.726 6.421 8.154
Expired (in usd per share) 9.146 10.157 11.293
Ending balance (in usd per share) 8.050 $ 7.367 $ 7.300
Options exercisable (in usd per share) 8.824    
Expected to vest (in usd per share) $ 6.970    
Outstanding, remaining contractual term 4 years 11 months 27 days    
Exercisable, remaining contractual term 2 years 10 months 13 days    
Expected to vest, remaining contractual term 7 years 11 months 9 days    
Outstanding, aggregate intrinsic value $ 20,120    
Exercisable, aggregate intrinsic value 10,237    
Expected to vest, aggregate intrinsic value $ 9,883