OPERATING SEGMENT REPORTING - Summary of Reportable Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating Segment Reporting
Revenue from gold and silver sales	$ 30,647	$ 40,706	$ 56,189	$ 64,446
Depreciation and depletion	(3,469)	(5,515)	(7,181)	(10,652)
Gross profit (loss)	4,235	4,059	(1,759)	(927)
Advanced projects - Other	(14,922)	(823)	(26,057)	(2,622)
Income (loss) from investment in Minera Santa Cruz S.A.	2,511	(1,853)	1,391	(2,427)
Segment income (loss)	(12,469)	(5,533)	(33,928)	(17,848)
General and Administrative and other	63	(1,478)	(357)	(3,644)
Loss before income and mining taxes	(12,406)	(7,011)	(34,285)	(21,492)
Capital expenditures	4,377	11,128	8,434	21,452
United States Reportable Segment [Member]
Operating Segment Reporting
Depreciation and depletion	(943)	(2,326)	(1,760)	(4,068)
Gross profit (loss)	748	2,950	(2,498)	545
Advanced projects - Other	(3)	116	(49)	32
Segment income (loss)	(499)	1,475	(5,242)	(1,878)
Capital expenditures	219	353	496	1,110
Canada
Operating Segment Reporting
Depreciation and depletion	(2,526)	(3,189)	(5,421)	(6,584)
Gross profit (loss)	6,460	2,658	7,813	1,168
Advanced projects - Other	(105)	(564)	(195)	(1,188)
Segment income (loss)	3,734	(2,187)	3,297	(7,736)
Capital expenditures	4,008	10,775	7,554	20,342
Mexico Reportable Segment [Member]
Operating Segment Reporting
Gross profit (loss)	(2,973)	(1,549)	(7,074)	(2,640)
Advanced projects - Other	(733)	(375)	(1,976)	(1,466)
Segment income (loss)	(3,706)	(1,934)	(9,050)	(4,123)
MSC
Operating Segment Reporting
Income (loss) from investment in Minera Santa Cruz S.A.	2,511	(1,853)	1,391	(2,427)
Segment income (loss)	2,511	(1,853)	1,391	(2,427)
Los Azules
Operating Segment Reporting
Advanced projects - Other	(14,081)		(23,837)
Segment income (loss)	(14,509)	(1,034)	(24,324)	(1,684)
Capital expenditures	150		384
Other
Operating Segment Reporting
Advanced projects - Other	(841)	(823)	(2,220)	(2,622)
Gold and silver sales
Operating Segment Reporting
Revenue from gold and silver sales	30,647	40,706	56,189	64,446
Gold and silver sales | United States Reportable Segment [Member]
Operating Segment Reporting
Revenue from gold and silver sales	9,996	26,343	21,739	39,236
Gold and silver sales | Canada
Operating Segment Reporting
Revenue from gold and silver sales	20,246	12,178	33,141	20,739
Gold and silver sales | Mexico Reportable Segment [Member]
Operating Segment Reporting
Revenue from gold and silver sales	405	2,185	1,309	4,471
Product [Member]
Operating Segment Reporting
Production costs applicable to sales	(22,943)	(31,132)	(50,767)	(54,721)
Product [Member] | United States Reportable Segment [Member]
Operating Segment Reporting
Production costs applicable to sales	(8,305)	(21,067)	(22,477)	(34,623)
Product [Member] | Canada
Operating Segment Reporting
Production costs applicable to sales	(11,260)	(6,331)	(19,907)	(12,987)
Product [Member] | Mexico Reportable Segment [Member]
Operating Segment Reporting
Production costs applicable to sales	(3,378)	(3,734)	(8,383)	(7,111)
Exploration
Operating Segment Reporting
Production costs applicable to sales	(4,293)	(6,916)	(7,503)	(11,872)
Exploration | United States Reportable Segment [Member]
Operating Segment Reporting
Production costs applicable to sales	(1,244)	(1,591)	(2,695)	(2,455)
Exploration | Canada
Operating Segment Reporting
Production costs applicable to sales	(2,621)	(4,281)	(4,321)	(7,716)
Exploration | Mexico Reportable Segment [Member]
Operating Segment Reporting
Production costs applicable to sales		(10)		(17)
Exploration | Los Azules
Operating Segment Reporting
Production costs applicable to sales	$ (428)	$ (1,034)	$ (487)	$ (1,684)