Annual report pursuant to Section 13 and 15(d)

Stock Incentive Plan - Stock Options Activity (Details)

v3.6.0.2
Stock Incentive Plan - Stock Options Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Number of Options [Roll Forward]      
Beginning balance (in shares) 4,139,440 3,893,573 4,573,378
Granted (in shares) 665,000 747,100 145,000
Exercised (in shares) (320,892) (332,600) (482,475)
Forfeited (in shares) (194,562) (168,633) (324,330)
Expired (in shares) (317,604)   (18,000)
Ending balance (in shares) 3,971,382 4,139,440 3,893,573
Options exercisable (in shares) 2,664,405    
Options expected to vest (in shares) 1,306,977    
Weighted Average Exercise Price [Roll Forward]      
Beginning balance (in usd per share) $ 7.740 $ 7.721 $ 7.528
Granted (in usd per share) 4.703 6.404 7.578
Exercised (in usd per share) 3.286 3.467 2.999
Forfeited (in usd per share) 8.154 9.409 12.226
Expired (in usd per share) 11.293   2.750
Ending balance (in usd per share) 7.300 $ 7.740 $ 7.721
Options exercisable (in usd per share) 7.850    
Expected to vest (in usd per share) $ 6.179    
Outstanding, remaining contractual term 5 years 6 months    
Exercisable, remaining contractual term 4 years 18 days    
Expected to vest, remaining contractual term 8 years 5 months 16 days    
Outstanding, aggregate intrinsic value $ 1,143    
Exercisable, aggregate intrinsic value 626    
Expected to vest, aggregate intrinsic value $ 517