|
Equity - Restricted Stock Units Narrative (Detail) (USD $)
|
3 Months Ended |
|
Mar. 31, 2015
|
Mar. 31, 2014
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Stock-based compensation expense |
$ 5,300,000 |
$ 4,400,000 |
| Total unrecognized compensation expense |
50,200,000 |
|
| Performance based stock options [Member] | Maximum |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Vesting period |
4 years |
|
| Restricted Stock Units |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Shares granted during the period |
418,584 |
|
| Other than options - granted in period, weighted average fair value |
$ 33.81 |
|
| Other than options - grant date fair value |
14,200,000 |
|
| Stock-based compensation expense |
2,300,000 |
2,800,000 |
| Total unrecognized compensation expense |
26,600,000 |
|
| Total unrecognized compensation expense weighted-average period |
1 year 6 months 0 days |
|
| 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 |
0 |
|
| Employee Stock Option |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Stock-based compensation expense |
3,000,000 |
1,600,000 |
| Total unrecognized compensation expense |
$ 23,600,000 |
|
| Total unrecognized compensation expense weighted-average period |
1 year 6 months 0 days |
|