Stockholders' Equity - Share Activity (Details)
|
3 Months Ended |
|
Mar. 31, 2018
$ / shares
shares
|
|---|
| Number of Shares |
|
| Beginning Balance (shares) |
578,394
|
| Granted (shares) |
510,253
|
| Vested (shares) |
(195,972)
|
| Forfeited (shares) |
(151,965)
|
| Ending Balance (shares) |
740,710
|
| Weighted Average Grant Date Fair Value |
|
| Begining Balance (usd per share) | $ / shares |
$ 58.35
|
| Granted (usd per share) | $ / shares |
72.46
|
| Vested (usd per share) | $ / shares |
55.16
|
| Forfeited (usd per share) | $ / shares |
62.99
|
| Ending Balance (usd per share) | $ / shares |
$ 67.96
|
| Restricted Stock Awards |
|
| Number of Shares |
|
| Beginning Balance (shares) |
401,804
|
| Granted (shares) |
321,798
|
| Vested (shares) |
(163,043)
|
| Forfeited (shares) |
(59,931)
|
| Ending Balance (shares) |
500,628
|
| Performance Stock Awards |
|
| Number of Shares |
|
| Beginning Balance (shares) |
84,762
|
| Granted (shares) |
0
|
| Vested (shares) |
(32,929)
|
| Forfeited (shares) |
(44,384)
|
| Ending Balance (shares) |
7,449
|
| Performance Stock Units |
|
| Number of Shares |
|
| Beginning Balance (shares) |
91,828
|
| Granted (shares) |
188,455
|
| Vested (shares) |
0
|
| Forfeited (shares) |
(47,650)
|
| Ending Balance (shares) |
232,633
|