INVESTMENT IN MINERA SANTA CRUZ S.A. ("MSC") - SAN JOSE MINE - Changes in Company's Investment in MSC (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Change in the investment in MSC
Investment in MSC, beginning balance			$ 150,064
Income tax recovery	$ (2,140)	$ 153	(3,278)	$ (2,503)
Dividends received			(7,231)	(4,927)
Investment in MSC, ending balance	140,356		140,356		$ 150,064
MSC
Change in the investment in MSC
Investment in MSC, beginning balance			150,064	162,320	162,320
Attributable net income from MSC	(3,773)	(553)	(3,343)	1,594	(2,328)
Amortization of fair value increments	(2,482)	(2,428)	(4,597)	(4,497)	(9,632)
Income tax recovery	3,990	$ 2,718	5,463	$ 2,830	11,916
Dividends received			(7,231)		(12,212)
Investment in MSC, ending balance	$ 140,356		$ 140,356		$ 150,064

Represents the amortization of fair value increments from the equity method investments.

No definition available.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of the period.

+ References

No definition available.

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- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee, before amortization, to which the equity method of accounting is applied.

+ References

No definition available.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount of distribution received from equity method investee for return of investment, classified as investing activities. Excludes distribution for return on investment, classified as operating activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21D
-URI http://asc.fasb.org/extlink&oid=98514028&loc=SL94080555-108585

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