|
Share-Based Payment - Additional Information (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2015
|
Mar. 31, 2014
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Payments made under share based compensation | $ 3.8 | $ 3.8 |
| Cost of share-based compensation accrued as an operating expense | $ (0.1) | $ 0.5 |
| Phantom shares | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Calculation period | 3 years | |