Equity Investments (Equity Investments Balance Sheet Disclosure) (Details) - USD ($) $ in Thousands  | 
Jun. 30, 2016  | 
Dec. 31, 2015  | 
|---|---|---|
| Equity Method Investments and Joint Ventures [Abstract] | ||
| Current assets | $ 105,614 | $ 105,537 | 
| Noncurrent assets | 1,330,877 | 1,293,925 | 
| Current liabilities | 41,238 | 56,559 | 
| Noncurrent liabilities | $ 146,642 | $ 155,995 | 
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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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- References No definition available. 
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