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IMPAIRMENTS (Details) - USD ($) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2014 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Goodwill [Line Items] |  |  |  |
Uranium spot market prices percentage decrease |  |  | 20.00% |
Impairment of plant and equipment and mineral properties |  | $ 0 | $ 8,224,000 | $ 80,071,000
Impairment of assets to be abandoned of |  | 0 | 8,224,000 | 80,071,000
Mineral properties |  | $ 92,625,000 | 91,031,000 |
Conventional Uranium Recovery |  |  |  |
Goodwill [Line Items] |  |  |  |
Impairment of assets to be abandoned of | $ 75,050,000 |  |  | 5,020,000
Reclassification to assets held-for-sale |  |  |  | $ 7,530,000
Cooper King, Marquez Ranch, and Nose Rock | Disposal Group, Disposed of by Sale, Not Discontinued Operations |  |  |  |
Goodwill [Line Items] |  |  |  |
Mineral properties |  |  | 1,300,000 |
Proceeds from the sale of mineral interests |  |  | 1,360,000 |
Uranerz Energy Corporation |  |  |  |
Goodwill [Line Items] |  |  |  |
Goodwill acquired during the period |  |  | $ 47,730,000 |

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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
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- Definition The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 958 -SubTopic 225 -Section 45 -Paragraph 11 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51659069&loc=d3e92212-112881 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Impairment -URI http://asc.fasb.org/extlink&oid=6515133 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51719941&loc=d3e2921-110230 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2420-110228 + Details
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