INVESTMENT IN MINERA SANTA CRUZ S.A. ("MSC") - SAN JOSE MINE - Summary of Operating Results from MSC (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
INVESTMENT IN MINERA SANTA CRUZ S.A. ("MSC") - SAN JOSE MINE
Income taxes recovery	$ (153)	$ 856	$ 2,503	$ 2,723
Income (loss) from investment in MSC, net of amortization	(263)	4,133	(73)	9,096
MSC
INVESTMENT IN MINERA SANTA CRUZ S.A. ("MSC") - SAN JOSE MINE
Net sales	60,835	58,581	109,178	110,653
Production costs applicable to sales	(52,415)	(38,832)	(89,114)	(76,559)
Net income (loss)	$ (1,126)	$ 10,973	$ 3,255	$ 19,221
Ownership interest (as a percent)	49.00%	49.00%	49.00%	49.00%
Net income (loss)	$ (553)	$ 5,377	$ 1,594	$ 9,418	$ 15,961
Amortization of fair value increments	(2,428)	(2,774)	(4,497)	(6,456)	(12,274)
Income taxes recovery	2,718	1,530	2,830	6,134	$ 9,264
Income (loss) from investment in MSC, net of amortization	$ (263)	$ 4,133	$ (73)	$ 9,096

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

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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The amount of the cost of sales reported by an equity method investment of the entity.

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The amount of net income (loss) reported by an equity method investment of the entity.

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The amount of revenue from sale of goods and services reduced by sales returns, allowances, and discounts reported by an equity method investment of the entity.

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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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