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INVENTORIES (Details Textual) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Disclosure of inventories [Line Items] |  |  |
Operating expense |  | $ 321.0 | $ 275.5
Non-current inventories | [1] | 78.7 | 103.3
Cerro San Pedro [Member] |  |  |
Disclosure of inventories [Line Items] |  |  |
Operating expense |  |  | 24.0
Inventory write-down |  |  | 26.6
Depreciation expense |  |  | 2.6
Inventories recognized [Member] |  |  |
Disclosure of inventories [Line Items] |  |  |
Operating expense |  | $ 302.8 | $ 259.1
[1] | Non-current inventories, which include heap leach inventories at Mesquite and low-grade stockpiled inventories at Rainy River, of $78.7 million (December 31, 2016 – $103.3 million) are expected to be recovered after one year.

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- Definition The amount of depreciation expense. Depreciation is the systematic allocation of depreciable amounts of tangible assets over their useful lives. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_112_c&doctype=Standard -URIDate 2017-03-09 + Details
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