Derivative Financial Instruments - Changes in Fair Value and Settlements of Commodity Derivative Contracts (Details) - USD ($) $ in Thousands |
3 Months Ended | |
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Mar. 31, 2017 |
Mar. 31, 2016 |
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| Gain Loss On Derivative Instruments Net Pretax [Abstract] | ||
| Derivative gain | $ (3,955) | $ (2,493) |
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- Definition Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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