CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 16,569	$ 12,380
Investments (note 2)	1,945	1,082
IVA taxes receivable	10,405us-gaap_ValueAddedTaxReceivableCurrent	11,739us-gaap_ValueAddedTaxReceivableCurrent
Inventories (note 3)	12,931us-gaap_InventoryNet	12,404us-gaap_InventoryNet
Other current assets	1,697us-gaap_OtherAssetsCurrent	2,096us-gaap_OtherAssetsCurrent
Total current assets	43,547us-gaap_AssetsCurrent	39,701us-gaap_AssetsCurrent
Mineral property interests	287,490us-gaap_MineralPropertiesNet	287,812us-gaap_MineralPropertiesNet
Investment in Minera Santa Cruz S.A. (note 5)	177,347	177,018
Property and equipment, net (note 6)	17,816us-gaap_PropertyPlantAndEquipmentNet	17,896us-gaap_PropertyPlantAndEquipmentNet
Other assets	533us-gaap_OtherAssetsNoncurrent	531us-gaap_OtherAssetsNoncurrent
TOTAL ASSETS	526,733us-gaap_Assets	522,958us-gaap_Assets
Current liabilities:
Accounts payable and accrued liabilities	19,875	21,654
Current portion of asset retirement obligation (note 4)	2,456	2,427
Total current liabilities	22,331us-gaap_LiabilitiesCurrent	24,081us-gaap_LiabilitiesCurrent
Asset retirement obligation, less current portion (note 4)	5,116	5,044
Deferred income tax liability	50,652	51,899
Deferred lease inducement	311us-gaap_DeferredRentCreditNoncurrent	319us-gaap_DeferredRentCreditNoncurrent
Other liabilities	400us-gaap_OtherLiabilitiesNoncurrent	400us-gaap_OtherLiabilitiesNoncurrent
Total liabilities	78,810us-gaap_Liabilities	81,743us-gaap_Liabilities
Shareholders' equity:
Common stock, no par value, 500,000 shares authorized; Common: 272,956 as of March 31, 2015 and 271,579 shares as of December 31, 2014 issued and outstanding Exchangeable: 27,574 shares as of March 31, 2015 and 28,521 shares as of December 31, 2014 issued and outstanding (note 6)	1,361,520us-gaap_CommonStockValue	1,360,668us-gaap_CommonStockValue
Accumulated deficit	(913,556)	(919,577)
Accumulated other comprehensive income (loss) income	(41)	124
Total shareholders' equity	447,923us-gaap_StockholdersEquity	441,215us-gaap_StockholdersEquity
TOTAL LIABILITIES & SHAREHOLDERS' EQUITY	526,733	522,958
Commitments and Contingencies (note 13)

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant