Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Options (Details)

v3.5.0.2
Stock-based Compensation - Options (Details)
 3 Months Ended 6 Months Ended
Jun. 30, 2016
USD ($)
shares
Jun. 30, 2015
USD ($)
Jun. 30, 2016
USD ($)
item
$ / shares
shares
Jun. 30, 2015
USD ($)
$ / shares
shares
Stock Based Compensation        
Share-based compensation | $ $ 2,014,000 $ 1,909,000 $ 3,452,000 $ 3,963,000
Employee Stock Option        
Stock Based Compensation        
Number of homogenous groups for purposes of determining fair values of options | item     3  
Contractual term of the option     10 years  
Weighted-average assumptions relating to options granted        
Risk-free interest rate (as a percent) 1.50% 1.90% 1.70% 1.80%
Expected term (in years) 7 years 7 years 6 years 4 months 24 days 6 years 6 months
Dividend yield (as a percent) 0.00% 0.00% 0.00% 0.00%
Expected volatility (as a percent) 76.90% 66.90% 63.30% 65.10%
Additional disclosures        
Options granted (in shares)     3,833,435 3,793,420
Grant-date weighted-average fair value (in dollars per share) | $ / shares     $ 1.59 $ 1.40
Total unrecognized compensation cost, net of estimated forfeitures | $ $ 7,000,000   $ 7,000,000  
Shares of common stock available for future grant 2,108,340   2,108,340  
Options exercised during the period (in shares)     11,977  
Employee Stock Option | Consultant        
Stock Based Compensation        
Contractual term of the option     10 years  
Employee Stock Option | Recipient Of Performance Shares        
Stock Based Compensation        
Share-based compensation | $ $ 0   $ 0  
Additional disclosures        
Options granted (in shares)     1,015,000 1,175,000
Options cancelled (in shares)     150,000  
Options outstanding 865,000   865,000  
Grant date fair value of performance stock options awards | $     $ 1,400,000  
Total unrecognized compensation cost, net of estimated forfeitures | $ $ 2,100,000   $ 2,100,000