|
Income Taxes - Deferred Tax Assets and Liabilities (Details) (USD $)
In Millions, unless otherwise specified |
Sep. 30, 2012
|
Dec. 31, 2011
|
|---|---|---|
| Deferred Tax Assets (Liabilities), Net [Abstract] | ||
| Deferred Tax Liabilities, Noncurrent | $ (31.8) | $ (23.0) |