Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Realized/unrealized embedded derivative, net	$ (738)	$ 1,837
Total sales, net	28,005	26,578
Dore
Disaggregation of Revenue [Line Items]
Less: Treatment and refining charges	(92)	(38)
Total sales, net	8,267	2,045
Gold Dore
Disaggregation of Revenue [Line Items]
Total sales, net	7,683	1,683
Silver Dore
Disaggregation of Revenue [Line Items]
Total sales, net	676	400
Concentrate
Disaggregation of Revenue [Line Items]
Less: Treatment and refining charges	(5,835)	(3,410)
Total sales, net	20,476	22,696
Gold Concentrate
Disaggregation of Revenue [Line Items]
Total sales, net	6,216	4,565
Silver Concentrate
Disaggregation of Revenue [Line Items]
Total sales, net	5,215	3,761
Copper Concentrate
Disaggregation of Revenue [Line Items]
Total sales, net	2,361	2,114
Lead Concentrate
Disaggregation of Revenue [Line Items]
Total sales, net	3,479	3,395
Zinc Concentrate
Disaggregation of Revenue [Line Items]
Total sales, net	$ 9,040	$ 12,271