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           Equity Investments (Equity Investments Balance Sheet Disclosure) (Details) (USD $) 
        In Thousands, unless otherwise specified  | 
        
           Mar. 31, 2014 
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           Dec. 31, 2013 
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|---|---|---|
| Equity Method Investments and Joint Ventures [Abstract] | ||
| Current assets | $ 168,313 | $ 146,075 | 
| Noncurrent assets | 3,004,333 | 2,567,225 | 
| Current liabilities | 291,642 | 233,726 | 
| Noncurrent liabilities | $ 824,263 | $ 664,848 | 
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- Details 
          
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- Definition 
          The amount of current assets reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          The amount of current liabilities reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          The amount of noncurrent assets reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          The amount of noncurrent liabilities reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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