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Inventory Components (Details) (USD $)
In Thousands, unless otherwise specified |
Jun. 30, 2013
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Dec. 31, 2012
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| Inventory Disclosure [Abstract] | ||
| Coal | $ 52,406 | $ 78,825 |
| Merchandise for resale | 36,476 | 35,363 |
| Supplies | 139,112 | 133,578 |
| Total Inventories | 227,994 | 247,766 |
| Excess of replacement cost of merchandise for resl inventories over carrying LIFO value | $ 18,734 | $ 19,700 |
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- Definition
Carrying amount as of the balance sheet date of coal, which is a combustible rock or minerals which are extracted from the ground and used as fuel. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The excess of replacement or current cost over the stated LIFO (last in first out) inventory value when the LIFO inventory method is utilized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of products used directly or indirectly in the manufacturing or production process, which may or may not become part of the final product. May also include items used in the storage, presentation or transportation of physical goods. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Carrying amount as of the balance sheet date of merchandise inventory purchased by a retailer, wholesaler or distributor and held for future sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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