Annual report pursuant to Section 13 and 15(d)

Stock Incentive Plan - Stock Options Activity (Details)

v3.3.1.900
Stock Incentive Plan - Stock Options Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Number of Options [Roll Forward]      
Beginning balance (in shares) 3,893,573 4,573,378 4,778,143
Granted (in shares) 747,100 145,000 598,360
Exercised (in shares) (332,600) (482,475) (682,619)
Forfeited (in shares) (168,633) (324,330) (120,506)
Expired (in shares)   (18,000)  
Ending balance (in shares) 4,139,440 3,893,573 4,573,378
Options exercisable (in shares) 2,821,735    
Options expected to vest (in shares) 1,317,705    
Weighted Average Exercise Price [Roll Forward]      
Beginning balance (in usd per share) $ 7.721 $ 7.528 $ 6.794
Granted (in usd per share) 6.404 7.578 9.101
Exercised (in usd per share) 3.467 2.999 3.037
Forfeited (in usd per share) 9.409 12.226 11.691
Expired (in usd per share)   2.750  
Ending balance (in usd per share) 7.740 $ 7.721 $ 7.528
Options exercisable (in usd per share) 7.500    
Expected to vest (in usd per share) $ 8.254    
Outstanding, remaining contractual term 5 years 3 months 15 days    
Exercisable, remaining contractual term 3 years 11 months 12 days    
Expected to vest, remaining contractual term 8 years 2 months 5 days    
Outstanding, aggregate intrinsic value $ 2,210    
Exercisable, aggregate intrinsic value 2,178    
Expected to vest, aggregate intrinsic value $ 32