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Summary of Significant Accounting Policies (Tables) | 9 Months Ended
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Sep. 30, 2017
Accounting Policies [Abstract] |
Estimated Useful Lives of Property, Plant and Equipment | Depreciation is calculated using the straight-line method over the estimated useful lives of the property, plant and equipment, which are:
|  | Years
Land improvements |  | 10
Plant and buildings |  | 5-15
Real estate properties |  | 10-40
Rail spur |  | 30
Vehicles |  | 3-5
Machinery, equipment and tooling |  | 3-15
Furniture and fixtures |  | 3-10
Deferred mining costs |  | 3
Reconciliation of Weighted-Average Common Shares Outstanding Used in the Calculation of Basic Net Income (Loss) Per Share and Diluted Net Income (Loss) Per Share | The following table reconciles the weighted-average common shares outstanding used in the calculation of basic net income (loss) per share to the weighted average common shares outstanding used in the calculation of diluted net income (loss) per share:
|  | Three Months Ended |  |  | Nine Months Ended |
|  | September 30, 2017 |  |  | September 30, 2017 |
Determination of Shares |  |  |  |  |  |  |  |
Weighted average common shares outstanding |  |  | 40,384 |  |  |  | 40,145 |
Assumed conversion of restricted stock |  |  | 32 |  |  |  | 112 |
Diluted weighted average common stock outstanding |  |  | 40,416 |  |  |  | 40,257 |

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- Definition Tabular disclosure of the weighted average number of shares used in calculating basic net earnings per share (or unit) and diluted earnings per share (or unit). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
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