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Derivative Financial Instruments - Additional Information (Detail) (USD $)
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12 Months Ended | ||
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Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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| Derivative Instruments And Hedging Activities [Line Items] | |||
| Unrealized gain (loss) on commodity contracts | $ 6,289,000 | $ (11,769,000) | $ 9,511,000 |
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Interest Rate Swap
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| Derivative Instruments And Hedging Activities [Line Items] | |||
| Realized gain (loss) on interest derivatives | (4,700,000) | ||
| Unrealized gain (loss) on commodity contracts | $ 4,400,000 | ||
| Derivative fixed interest rate | 5.21% | ||
| Derivative contract expiration date | Aug. 01, 2010 | ||
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- Definition
Fixed interest rate related to the interest rate derivative. No definition available.
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- Definition
Date the derivative contract matures, in CCYY-MM-DD format. No definition available.
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- Definition
The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of open agreements to purchase or sell mineral resources, energy, and agricultural products at some future point held at each balance sheet date, that was included in earnings for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Realized Gain Loss On Interest Derivative Contracts No definition available.
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