Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Realized/unrealized embedded derivative, net	$ (2,303)	$ (24)	$ (1,732)	$ 511
Sales Revenue, Goods, Net, Total	30,768	21,391	$ 62,919	45,727
Concentrate Sale Percentage Based On Provisional Sales Price			100.00%
Dore [Member]
Disaggregation of Revenue [Line Items]
Less: Treatment and refining charges	(38)	(5)	$ (63)	(22)
Total sales, net	2,156	1,451	4,337	3,082
Dore [Member] \| Gold
Disaggregation of Revenue [Line Items]
Sales	1,722	1,435	3,631	3,062
Dore [Member] \| Silver
Disaggregation of Revenue [Line Items]
Sales	472	21	769	42
Concentrate [Member]
Disaggregation of Revenue [Line Items]
Less: Treatment and refining charges	(1,261)	(1,479)	(3,095)	(2,987)
Total sales, net	30,915	19,964	60,314	42,134
Concentrate [Member] \| Gold
Disaggregation of Revenue [Line Items]
Sales	5,396	4,514	10,937	11,600
Concentrate [Member] \| Silver
Disaggregation of Revenue [Line Items]
Sales	8,803	5,604	14,884	12,892
Concentrate [Member] \| Copper
Disaggregation of Revenue [Line Items]
Sales	2,638	1,219	5,018	2,529
Concentrate [Member] \| Lead
Disaggregation of Revenue [Line Items]
Sales	3,498	2,316	7,345	4,254
Concentrate [Member] \| Zinc
Disaggregation of Revenue [Line Items]
Sales	$ 11,841	$ 7,790	$ 25,225	$ 13,846

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- Definition

The aggregate cost of goods produced and sold and services rendered during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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+ References

No definition available.

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- Definition

Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

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Aggregate revenue from the sale of minerals and related products, and from rendering services such as exploration, development, mining, processing and providing mining support activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(a),(d))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Aggregate revenue during the period from sale of goods in the normal course of business, before deducting returns, allowances and discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(a))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(a))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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