Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plan - Summary of Stock Option Activity and Related Information (Details)

v3.8.0.1
Equity Incentive Plan - Summary of Stock Option Activity and Related Information (Details) - $ / shares
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Weighted Average Exercise Price      
Outstanding at January 1 (in dollars per share) $ 4.57 $ 4.57  
Granted (in dollars per share) 2.43 0  
Exercised (in dollars per share) 0 3.48  
Forfeited/Expired/Exchanged (in dollars per share) 6.25 0  
Outstanding at December 31 (in dollars per share) $ 2.79 $ 4.57 $ 4.57
Equity Incentive Plan [Member]      
Stock Options      
Outstanding at January 1 (in shares) 1,385,204 1,332,323  
Granted (in shares) 167,725 96,138  
Exercised (in shares) (26,743) (4,607)  
Forfeited/Expired/Exchanged (in shares) (293,950) (38,650)  
Outstanding at December 31 (in shares) 1,232,236 1,385,204 1,332,323
Exercisable at December 31 (in shares) 910,436 862,354  
Weighted Average Exercise Price      
Outstanding at January 1 (in dollars per share) $ 6.89 $ 6.94  
Granted (in dollars per share) 2.99 5.95  
Exercised (in dollars per share) 0.42 5.00  
Forfeited/Expired/Exchanged (in dollars per share) 7.14 6.68  
Outstanding at December 31 (in dollars per share) 6.44 6.89 $ 6.94
Exercisable at December 31 (in dollars per share) $ 6.52 $ 6.56  
Weighted Average Remaining Life (in years)      
Outstanding (in years) 6 years 9 months 18 days 7 years 6 months 8 years 4 months 24 days
Exercisable at December 31 (in years) 6 years 7 months 6 days 7 years 2 months 12 days