Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Summary of non-vested stock options (Details 2)

v3.19.1
Stock-based Compensation - Summary of non-vested stock options (Details 2) - $ / shares
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Shares    
Non-vested shares at December 31, 2017 (in shares) 1,424,651 1,180,030
Granted 0 1,260,000
Vested (in shares) (427,651) (245,402)
Cancelled, expired or forfeited (in shares) (70,500) (769,977)
Non-vested shares at December 31, 2018 (in shares) 926,500 1,424,651
Weighted Average Grant Date Fair Value    
Non-vested shares at December 31, 2016 (in dollars per share) $ 0.99 $ 1.56
Granted (in dollars per share) 0 0.79
Vested (in dollars per share) 1.16 1.76
Cancelled, expired or forfeited (in dollars per share) 1.10 1.28
Non-vested shares at December 31, 2017 (in dollars per share) $ 0.91 $ 0.99