Stock-Based Compensation - Performance based stock options (Details) - Service Based Stock Options - Vesting based on service period |
6 Months Ended |
|---|---|
|
Jun. 30, 2019
$ / shares
shares
| |
| Stock-Based Compensation | |
| Options granted | shares | 1,967,304 |
| Options exercise price | $ 14.85 |
| Weighted average grant-date fair value (per share) | $ 10.07 |