| East Tennessee Materials and Energy Corporation (''M&EC'') (Tables) | 3 Months Ended | |||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mar. 31, 2019 | ||||||||||||||||||||||||||
| Discontinued Operations and Disposal Groups [Abstract] | ||||||||||||||||||||||||||
| Schedule of Change in Asset Retirement Obligation | The following reflects changes to the closure liabilities for the M&EC facility from year end 2018: 
 
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| X | ||||||||||
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- References No definition available. 
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| X | ||||||||||
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- Definition Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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