Equity - Restricted Stock Units Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions |
3 Months Ended |
9 Months Ended |
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Stock-based compensation expense |
$ 6.1
|
$ 4.2
|
$ 16.9
|
$ 13.8
|
| Total unrecognized compensation expense |
47.0
|
|
$ 47.0
|
|
| Unvested restricted stock units |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Shares granted during the period (in shares) |
|
|
581,777
|
|
| Stock-based compensation expense |
2.6
|
1.7
|
$ 7.3
|
6.3
|
| Other than options - granted in period, weighted average fair value (in dollars per share) |
|
|
$ 29.69
|
|
| Other than options - grant date fair value (in dollars per share) |
|
|
$ 17.3
|
|
| Total unrecognized compensation expense |
24.7
|
|
$ 24.7
|
|
| Total unrecognized compensation expense weighted-average period |
|
|
2 years
|
|
| Unvested restricted stock units | Maximum |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Vesting period |
|
|
3 years
|
|
| Performance Shares |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
|
| Shares granted during the period (in shares) |
|
|
153,992
|
|
| Stock-based compensation expense |
$ 0.9
|
$ 0.4
|
$ 2.0
|
$ 0.4
|