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MINERAL PROPERTY INTERSTS AND ASSET RETIREMENT OBLIGATIONS (Details) (USD $) | 3 Months Ended | 6 Months Ended | 12 Months Ended | 0 Months Ended | 3 Months Ended | 6 Months Ended |  | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended
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Jun. 30, 2014 | Jun. 30, 2013 | Jun. 30, 2014 | Jun. 30, 2013 | Dec. 31, 2013 | Jun. 30, 2014 Subsequent Event [Member] | Jun. 30, 2014 Argentina Reportable Segment [Member] | Jun. 30, 2013 Argentina Reportable Segment [Member] | Jun. 30, 2014 Argentina Reportable Segment [Member] | Jun. 30, 2013 Argentina Reportable Segment [Member] | Jun. 30, 2014 Tonkin Complex And El Gallo One Mine Complex [Member] item | Jun. 30, 2014 Tonkin Complex [Member] | Jun. 30, 2014 El Gallo Complex [Member] | Jun. 30, 2014 El Gallo Complex [Member] | Jun. 30, 2013 Telken Tenements [Member] Argentina Reportable Segment [Member] | Jun. 30, 2013 Telken Tenements [Member] Argentina Reportable Segment [Member] | Jun. 30, 2013 Este Tenements [Member] Argentina Reportable Segment [Member] | Jun. 30, 2013 Este Tenements [Member] Argentina Reportable Segment [Member] | Jun. 30, 2013 Piramides Tenements [Member] Argentina Reportable Segment [Member] | Jun. 30, 2013 Piramides Tenements [Member] Argentina Reportable Segment [Member] | Jun. 30, 2013 Tobias Tenements [Member] Argentina Reportable Segment [Member] | Jun. 30, 2013 Tobias Tenements [Member] Argentina Reportable Segment [Member] | Jun. 30, 2013 Exploration Properties Located In Santa Cruz Province Argentina [Member] | Jun. 30, 2013 Exploration Properties Located In Santa Cruz Province Argentina [Member] | Jun. 30, 2014 Los Azules Copper Project [Member] | Jun. 30, 2014 Los Azules Copper Project [Member] | Jun. 30, 2014 Los Azules Copper Project [Member] Argentina Reportable Segment [Member] | Jun. 30, 2014 Los Azules Copper Project [Member] Argentina Reportable Segment [Member]
Mineral Property Interests [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of most significant properties subject to reclamation obligations |  |  |  |  |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Undiscounted estimated reclamation costs |  |  |  |  |  |  |  |  |  |  |  | $ 2,700,000 | $ 4,600,000 | $ 4,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash bonding for mineral properties in the United States | 4,817,000 |  | 4,817,000 |  | 5,183,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reduction in cash bonding requirements |  |  | (367,000) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of annual fees on surety bonds |  |  |  |  |  | 1.50% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of upfront deposit on surety bonds |  |  |  |  |  | 10.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization of mineral property interests and asset retirement obligations |  |  | 626,000 | 956,000 |  |  |  |  |  |  |  |  | 300,000 | 600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization of capitalized asset retirement costs |  |  |  |  |  |  |  |  |  |  |  |  | 100,000 | 100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Impairment charges | 120,398,000 | 27,729,000 | 120,398,000 | 27,729,000 |  |  | 120,398,000 | 27,729,000 | 120,398,000 | 27,729,000 |  |  |  |  | 13,792,000 | 13,792,000 | 2,784,000 | 2,784,000 | 5,079,000 | 5,079,000 | 6,074,000 | 6,074,000 | 27,700,000 | 27,700,000 | 120,400,000 | 120,398,000 | 120,398,000 | 120,398,000
Recovery of deferred income tax | 22,500,000 | 4,800,000 | 22,500,000 | 4,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,300,000 | 2,300,000 | 22,500,000 | 22,500,000 |  |
Changes in the asset retirement obligations |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset retirement obligation liability, beginning balance |  |  | 7,247,000 | 6,359,000 | 6,359,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Settlements |  |  | (18,000) |  | (60,000) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Accretion of liability | 108,000 | 121,000 | 209,000 | 234,000 | 461,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Adjustment reflecting updated estimates |  |  | (42,000) |  | 487,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset retirement obligation liability, ending balance | 7,396,000 |  | 7,396,000 |  | 7,247,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Current portion of the asset retirement obligation | $ 1,455,000 |  | $ 1,455,000 |  | $ 1,392,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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- Definition Current portion of reclamation reserve to restore a mining or drilling site to the condition agreed upon within the mining or drilling contract. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6911-107765 + Details
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- Definition The net cash inflow or outflow for the increase (decrease) associated with funds that are not available for withdrawal or use (such as funds held in escrow) and are associated with underlying transactions that are classified as investing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585 + Details
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