Stock-Based Compensation - Option Activity (Details)
|
3 Months Ended |
|
Mar. 31, 2019
USD ($)
$ / shares
shares
|
|---|
| Options |
|
| Outstanding, beginning of period (in shares) | shares |
4,559,334
|
| Granted (in shares) | shares |
137,500
|
| Exercised (in shares) | shares |
0
|
| Forfeited (in shares) | shares |
(2,667)
|
| Expired (in shares) | shares |
(333)
|
| Outstanding, end of period (in shares) | shares |
4,693,834
|
| Exercisable (in shares) | shares |
2,531,133
|
| Weighted Average Exercise Price |
|
| Outstanding, beginning of period (in dollars per share) | $ / shares |
$ 16.55
|
| Granted (in dollars per share) | $ / shares |
11.30
|
| Exercised (in dollars per share) | $ / shares |
0.00
|
| Forfeited (in dollars per share) | $ / shares |
18.03
|
| Expired (in dollars per share) | $ / shares |
18.48
|
| Outstanding, end of period (in dollars per share) | $ / shares |
16.40
|
| Exercisable (in dollars per share) | $ / shares |
$ 16.09
|
| Outstanding, weighted average remaining term |
8 years
|
| Exercisable, weighted average remaining term |
7 years 8 months 23 days
|
| Outstanding, aggregate intrinsic value | $ |
$ 0
|
| Exercisable, aggregate intrinsic value | $ |
$ 0
|