|
Other Assets (Details Textual) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2011
|
Dec. 31, 2010
|
|---|---|---|
| Other Assets (Textual) [Abstract] | ||
| Fair value of fuel and commodity hedges included in Other current assets | $ 3.0 | $ 3.5 |
| Fair value of interest rate swaps included in notes and other receivables | $ 5.2 |