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FAIR VALUE ACCOUNTING - Fair Value Measurements, Nonrecurring (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Inflation Rate	2.00%	2.00%
Level 3 | Nichols Ranch Project and mineral properties in the ISR and Conventional segments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate	10.00%
United States Inflation Rate	2.00%
Level 3 | Nichols Ranch Project
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate	10.00%
United States Inflation Rate	2.00%
Level 3 | Minimum | Nichols Ranch Project and mineral properties in the ISR and Conventional segments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short and Long Term Uranium Price	$ 38.90
Level 3 | Minimum | Nichols Ranch Project
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short and Long Term Uranium Price	37.95
Level 3 | Maximum | Nichols Ranch Project and mineral properties in the ISR and Conventional segments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short and Long Term Uranium Price	62.10
Level 3 | Maximum | Nichols Ranch Project
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short and Long Term Uranium Price	$ 65.00

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Fair Value Inputs, Uranium Price

+ References

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+ References

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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