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Inventories | 9 Months Ended
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Sep. 30, 2021
Inventory Disclosure [Abstract] |
Inventories | Inventories Inventories are summarized as follows:
| SEPTEMBER 30 2021 |  | DECEMBER 31 2020
Coal | $ | 17,172 |  |  | $ | 17,695 |
Mining supplies | 33,783 |  |  | 29,856 |
Total inventories | $ | 50,955 |  |  | $ | 47,551 |

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- Definition The entire disclosure for inventory. Includes, but is not limited to, the basis of stating inventory, the method of determining inventory cost, the classes of inventory, and the nature of the cost elements included in inventory. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -URI http://asc.fasb.org/topic&trid=2126998 + Details
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