COMMITMENTS AND CONTINGENCIES (Narrative) (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
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| Loss Contingencies [Line Items] | |||
| loss contingency recorded | $ 0 | ||
| Future Operating Lease Commitments | |||
| Operating Lease, Contract Term, Maximum (in years) | 20 years | ||
| Reclamation Deposits and Surety Bonds | |||
| Security placed with the State of Utah and the BLM | $ 19,000,000 | $ 18,800,000 | |
| Long-term restricted cash deposits | 482,000 | 481,000 | $ 3,481,000 |
| Surety bonds issued by an insurer | 18,500,000 | $ 18,300,000 | |
| Minimum [Member] | |||
| Loss Contingencies [Line Items] | |||
| Estimate of possible Loss | 22,000,000 | ||
| Maximum [Member] | |||
| Loss Contingencies [Line Items] | |||
| Estimate of possible Loss | $ 28,000,000 |
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- Definition Represents the value of reclamation deposits and surety bonds as of the balance sheet date. No definition available.
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- References No definition available.
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- Definition Represents the value of surety bonds secured by an insurer as of the balance sheet date. No definition available.
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- Definition Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Reflects the estimated amount of loss from the specified contingency as of the balance sheet date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The amount of loss pertaining to the specified contingency that was charged against earnings in the period, including the effects of revisions in previously reported estimates. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- References No definition available.
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- Definition Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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