Share Based Compensation - Stock Options (Details) - $ / shares
|
6 Months Ended |
Jun. 30, 2018 |
Jun. 30, 2017 |
| Avgwtd grant-date fair value |
|
|
| Modified to liability to be cash settled (in dollars per share) |
|
$ 2.57
|
| Avgwtd exercise price(1) |
|
|
| Modified to liability to be cash settled (in dollars per share) |
|
$ 2.54
|
| Units |
|
|
| Modified to liability to be cash settled (in shares) |
|
(156,273)
|
| Stock options |
|
|
| Share Based Compensation |
|
|
| Contractual life |
10 years
|
|
| Avgwtd grant-date fair value |
|
|
| Outstanding at the beginning of period |
$ 3.66
|
$ 3.40
|
| Granted (in dollars per share) |
6.51
|
6.16
|
| Forfeited (in dollars per share) |
6.26
|
2.73
|
| Exercised (in dollars per share) |
2.54
|
2.44
|
| Outstanding at the end of period |
3.76
|
3.57
|
| Vested (in dollars per share) |
3.24
|
3.04
|
| Nonvested (in dollars per share) |
4.83
|
3.96
|
| Avgwtd exercise price(1) |
|
|
| Outstanding at the beginning of period |
5.71
|
4.90
|
| Granted (in dollars per share) |
14.25
|
13.51
|
| Forfeited (in dollars per share) |
13.73
|
2.99
|
| Exercised (in dollars per share) |
2.45
|
2.54
|
| Outstanding at the end of the period |
6.04
|
5.43
|
| Vested (in dollars per share) |
4.46
|
3.81
|
| Nonvested (in dollars per share) |
$ 9.26
|
$ 6.63
|
| Units |
|
|
| Outstanding at the beginning of period |
9,078,728
|
8,669,475
|
| Granted (in shares) |
359,618
|
447,795
|
| Forfeited (in shares) |
(7,682)
|
(113,175)
|
| Exercised |
(5,000)
|
(73,406)
|
| Outstanding at the end of the period |
9,425,664
|
8,774,416
|
| Vested (in shares) |
6,331,146
|
3,737,939
|
| Nonvested (in shares) |
3,094,518
|
5,036,477
|