Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Payments - Restricted Common Stock (Details)

v3.5.0.2
Stock-Based Payments - Restricted Common Stock (Details)
$ / shares in Units, $ in Millions
9 Months Ended
Sep. 30, 2016
USD ($)
$ / shares
shares
Restricted stock  
Shares  
Unvested at beginning of year (in shares) | shares 256,881
Vested (in shares) | shares (177,330)
Repurchased (in shares) | shares (73,334)
Unvested at end of period (in shares) | shares 6,217
Weighted Average Grant Date Fair Value  
Unvested at beginning of year (in dollars per share) | $ / shares $ 0.38
Vested (in dollars per share) | $ / shares 0.39
Repurchased (in dollars per share) | $ / shares 0.38
Unvested at end of period (in dollars per share) | $ / shares $ 0.98
Performance-based restricted stock  
Stock-based payments  
Additional stock-based compensation expense recorded related to achievement of certain performance-based milestones | $ $ 1.0