OPERATING SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Segment Reporting
Gold and silver sales	$ 45,303us-gaap_RevenueMineralSales	$ 45,982us-gaap_RevenueMineralSales	$ 5,966us-gaap_RevenueMineralSales
Production costs applicable to sales	(40,608)us-gaap_CostOfGoodsSold	(34,594)us-gaap_CostOfGoodsSold	(3,861)us-gaap_CostOfGoodsSold
Mine operating costs			(8,507)us-gaap_DirectOperatingCosts
Mine construction costs	(1,723)us-gaap_OtherConstructionCosts	(1,383)us-gaap_OtherConstructionCosts	(14,260)us-gaap_OtherConstructionCosts
Mine development costs	(1,829)us-gaap_ConstructionAndDevelopmentCosts	(847)us-gaap_ConstructionAndDevelopmentCosts
Exploration costs	(11,332)us-gaap_ExplorationExpenseMining	(24,829)us-gaap_ExplorationExpenseMining	(47,179)us-gaap_ExplorationExpenseMining
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization)	(5,284)	846	20,835
Impairment of investment in MSC	(21,162)	(95,878)
Impairment of mineral property interests and property and equipment	(353,736)us-gaap_AssetImpairmentCharges	(62,963)us-gaap_AssetImpairmentCharges	(18,468)us-gaap_AssetImpairmentCharges
Gain (loss) on sale of assets	26	(6,743)	1,110
Operating loss	(410,165)us-gaap_OperatingIncomeLoss	(200,397)us-gaap_OperatingIncomeLoss	(91,405)us-gaap_OperatingIncomeLoss
Income tax recovery	107,170us-gaap_IncomeTaxExpenseBenefit	53,365us-gaap_IncomeTaxExpenseBenefit	27,244us-gaap_IncomeTaxExpenseBenefit
Investment in Minera Santa Cruz S.A.	177,018	212,947	273,948
Mineral property interests	287,812us-gaap_MineralPropertiesNet	642,968us-gaap_MineralPropertiesNet	767,067us-gaap_MineralPropertiesNet
Total assets	522,958us-gaap_Assets	923,066us-gaap_Assets	1,150,937us-gaap_Assets
Argentina
Operating Segment Reporting
Exploration costs	(2,453)	(14,776)	(25,091)
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization)	(5,284)	846	20,835
Impairment of investment in MSC	(21,162)	(95,878)
Impairment of mineral property interests and property and equipment	(255,313)	(27,729)	(179)
Gain (loss) on sale of assets		(316)
Operating loss	(285,800)	(139,784)	(8,156)
Income tax recovery	74,952	38,015	21,129
Investment in Minera Santa Cruz S.A.	177,018	212,947	273,948
Mineral property interests	202,889	458,203	539,092
Total assets	382,637	674,269	825,047
Mexico
Operating Segment Reporting
Gold and silver sales	45,303	45,982	5,966
Production costs applicable to sales	(40,608)	(34,594)	(3,861)
Mine operating costs			(8,507)
Mine construction costs	(1,723)	(1,383)	(14,260)
Mine development costs	(1,829)	(847)
Exploration costs	(5,468)	(6,658)	(15,918)
Impairment of mineral property interests and property and equipment			(1,343)
Operating loss	(10,101)	(2,998)	(43,417)
Income tax recovery	371	495
Mineral property interests	10,696	11,984	12,707
Total assets	58,936	54,131	47,359
United States
Operating Segment Reporting
Exploration costs	(3,060)	(2,952)	(5,060)
Impairment of mineral property interests and property and equipment	(98,423)	(35,234)	(16,946)
Gain (loss) on sale of assets		(6,430)
Operating loss	105,797	(47,422)	(25,144)
Income tax recovery	31,632	14,855	6,115
Mineral property interests	74,227	172,781	215,268
Total assets	74,806	177,248	220,148
Corporate & Other
Operating Segment Reporting
Exploration costs	(351)	(443)	(1,110)
Gain (loss) on sale of assets		3
Operating loss	(8,467)	(10,193)	(14,688)
Income tax recovery	215
Total assets	$ 6,579	$ 17,418	$ 58,383

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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The aggregate costs related to construction and development services during the reporting period.

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Total costs related to goods produced and sold during the reporting period.

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The aggregate direct operating costs incurred during the reporting period.

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This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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Exploration expenses (including prospecting) related to the mining industry would be included in operating expenses. Exploration costs include costs incurred in identifying areas that may warrant examination and in examining specific areas that are considered to have prospects of mineral reserves.

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Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.

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This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

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Mineral properties, net of adjustments.

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The net result for the period of deducting operating expenses from operating revenues.

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Other costs incurred and are directly related to construction and development services.

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Aggregate revenue from the sale of minerals and related products, and from rendering services such as exploration, development, mining, processing and providing mining support activities.

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