Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Summary of Stock Option Activity (Details)

v3.10.0.1
Stock-based Compensation - Summary of Stock Option Activity (Details) - 2014 Plan
$ / shares in Units, shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2018
USD ($)
$ / shares
shares
Options Outstanding  
Outstanding at beginning of year (in shares) | shares 3,156
Granted (in shares) | shares 3,925
Exercised (in shares) | shares (1)
Forfeited (in shares) | shares (429)
Expired (in shares) | shares (185)
Outstanding at end of year (in shares) | shares 6,466
Vested and expected to vest (in shares) | shares 6,466
Exercisable at year end (in shares) | shares 2,149
Weighted Average Exercise Price  
Outstanding at beginning of year (in dollars per share) | $ / shares $ 4.96
Granted (in dollars per share) | $ / shares 1.93
Exercised (in dollars per share) | $ / shares 1.13
Forfeited (in dollars per share) | $ / shares 4.67
Expired (in dollars per share) | $ / shares 7.91
Outstanding at end of year (in dollars per share) | $ / shares 3.05
Vested and expected to vest (in dollars per share) | $ / shares 3.05
Exercisable at year end (in dollars per share) | $ / shares $ 5.22
Weighted Average Remaining Contractual Life (Years), Ending Balance 8 years 4 months 2 days
Weighted Average Remaining Contractual Life (Years), Vested and expected to vest 8 years 4 months 2 days
Weighted Average Remaining Contractual Life (Years), Exercisable 6 years 26 days
Aggregate Intrinsic Value, Ending Balance | $ $ 58
Aggregate Intrinsic Value, Vested and expected to vest | $ 58
Aggregate Intrinsic Value, Exercisable | $ $ 37