NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	6 Months Ended
Jun. 30, 2012	Jan. 24, 2012 MSC	Jan. 24, 2012 Minera Andes MSC	Jan. 24, 2012 Minera Andes Los Azules Copper Deposit
Nature of Operations and Basis of Presentation
Period for determining current portion of ore stockpiles	12 months
Period within which ore stockpile inventories are not expected to be processed, classified as long-term	12 months
Interest acquired (as a percent)		49.00%	49.00%	100.00%

Percentage of voting equity interests acquired in the business combination.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7659399&loc=d3e1392-128463

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant