|
Income Taxes - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified |
Sep. 30, 2012
|
Dec. 31, 2011
|
|---|---|---|
| Income Taxes [Line Items] | ||
| Current tax liability | $ 2.8 | |
| Deferred tax liability | 85.6 | 68.8 |
| Current tax recoverable | $ 0.3 |