| **Financial Instruments (Carrying amounts and fair value of the financial instruments) (Details) (USD $)In Thousands, unless otherwise specified** | Mar. 31, 2013 | Dec. 31, 2012 |
|----------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Carrying Value Disclosures [Abstract]**                                                                                                          |          |          |
| Current and Long-term Debt and Capital Lease Obligations                                                                                           | $ 966,394     | $ 957,663     |
| Other Liabilities                                                                                                                                  | 25,675        | 25,511        |
| **Fair Value Disclosure [Abstract]**                                                                                                               |          |          |
| Current and Long-term Debt and Capital Lease Obligations, Fair Value Disclosure                                                                    | 970,071       | 979,594       |
| Other Liabilities, Fair Value Disclosure                                                                                                           | $ 24,850      | $ 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
This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.
+ References
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| - 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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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This element represents the fair value of liabilities categorized as other which are not in and of themselves material enough to require separate disclosure.
+ References
No definition available.
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