v2.4.0.6

Fair Value of Financial Instruments and Non-Financial Assets and Liabilities (Details 1) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified | Jun. 30, 2012 | Dec. 31, 2011
--- | --- | ---
Estimated fair value of long-term debt |  |
Long-term debt (including current portion) | $ 624,430 | $ 612,418
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |
Estimated fair value of long-term debt |  |
Long-term debt (including current portion) |  |
Significant Other Observable Inputs (Level 2) [Member] |  |
Estimated fair value of long-term debt |  |
Long-term debt (including current portion) | 624,430 | 612,418
Unobservable Inputs (Level 3) [Member] |  |
Estimated fair value of long-term debt |  |
Long-term debt (including current portion) |  |

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- Details
Name: | us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition The fair value amount of long-term debt 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 No definition available. + Details
Name: | us-gaap_LongTermDebtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant