Quarterly report pursuant to Section 13 or 15(d)

Stock-based compensation - Summary of Status of Company's Restricted Stock Option Activity (Details)

v3.7.0.1
Stock-based compensation - Summary of Status of Company's Restricted Stock Option Activity (Details)
 6 Months Ended
Jun. 30, 2017
$ / shares
shares
Number of Shares  
Beginning balance (in shares) | shares 1,857,012
Granted (in shares) | shares 960,000
Cancelled, expired, or forfeited (in shares) | shares (656,477)
Ending balance (in shares) | shares 2,160,535
Weighted Average Exercise Price  
Beginning balance (in dollars per share) | $ / shares $ 4.28
Granted (in dollars per share) | $ / shares 2.13
Cancelled, expired, or forfeited (in dollars per share) | $ / shares 3.21
Ending balance (in dollars per share) | $ / shares $ 3.65
Restricted Stock  
Number of Shares  
Beginning balance (in shares) | shares 716,250
Granted (in shares) | shares 410,000
Vested (in shares) | shares (81,750)
Cancelled, expired, or forfeited (in shares) | shares (169,500)
Ending balance (in shares) | shares 875,000
Weighted Average Exercise Price  
Beginning balance (in dollars per share) | $ / shares $ 2.73
Granted (in dollars per share) | $ / shares 2.13
Vested (in dollars per share) | $ / shares 2.73
Cancelled, expired, or forfeited (in dollars per share) | $ / shares 2.73
Ending balance (in dollars per share) | $ / shares $ 2.45