| **Financial Instruments (Carrying amounts and fair value of the financial instruments) (Details) (USD $)In Thousands, unless otherwise specified** | Sep. 30, 2013 | Dec. 31, 2012 |
|----------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Carrying Amount**                                                                                                                                |          |          |
| Current and long-term debt and capital lease obligations                                                                                           | $ 1,090,758   | $ 957,663     |
| Other liabilities                                                                                                                                  | 31,608        | 25,511        |
| **Fair Value**                                                                                                                                     |          |          |
| Current and long-term debt and capital lease obligations                                                                                           | 1,090,281     | 979,594       |
| Other liabilities                                                                                                                                  | $ 30,246      | $ 24,766      |

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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.
+ References
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| - Definition
Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The aggregate carrying amount, as of the balance sheet date, of liabilities not separately disclosed in the balance sheet.
+ References
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| - Definition
Fair value portion of other liabilities.
+ References
No definition available.
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