Segment Reporting (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Number of reportable segments | segment			2
Total sales, net	$ 21,098	$ 29,374	$ 49,103	$ 55,952
Exploration expense	901	3,232	5,843	6,718
Net income (loss)	(1,812)	1,798	(4,933)	2,680
Capital expenditures	2,164	9,367	8,577	21,248
Change in capital expenditures in accounts payable			(3,120)	(1,214)
Non - cash additions			1,097	1,024
Capital expenditures on a cash basis			10,600	21,438
Assets	188,776		188,776		$ 193,012
Mexico
Total sales, net	12,522	27,834	34,670	54,412
Net income (loss)	(1,283)	3,963	(2,235)	7,359
Capital expenditures	781	4,653	2,760	9,335
Assets	84,458		84,458		98,718
Nevada
Total sales, net	8,576	1,540	14,433	1,540
Net income (loss)	(884)	445	(1,677)	26
Capital expenditures	1,379	4,714	5,777	11,913
Assets	85,800		85,800		84,669
Corporate and Other
Net income (loss)	355	(2,610)	(1,021)	(4,705)
Capital expenditures	4		40
Assets	18,518		18,518		$ 9,625
Exploration expenses
Exploration expense	551	631	1,706	2,081
Exploration expenses | Mexico
Exploration expense	127	527	1,095	1,595
Exploration expenses | Nevada
Exploration expense	416	65	593	448
Exploration expenses | Corporate and Other
Exploration expense	$ 8	$ 39	$ 18	$ 38