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Quantitative Information About Level Three Fair Value Measurements (Detail) (Fuel price derivatives - diesel, USD $)
In Thousands, unless otherwise specified |
9 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|
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Sep. 30, 2013
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Jun. 30, 2013
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Dec. 31, 2012
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Sep. 30, 2012
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Jun. 30, 2012
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Dec. 31, 2011
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Sep. 30, 2013
Option Model
Minimum
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Sep. 30, 2013
Option Model
Maximum
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| Fair Value Inputs, Assets, Quantitative Information [Line Items] | ||||||||
| Fair value | $ (517) | $ 498 | $ (107) | $ (414) | $ 3,398 | $ (25) | ||
| Future retail price of diesel (in dollars per gallon) | 3.71 | 3.94 | ||||||