OPERATING SEGMENT REPORTING - Summary of Reportable Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Segment Reporting
Revenue from gold and silver sales	$ 25,988	$ 37,129	$ 82,177	$ 101,575
Depreciation and depletion	(4,313)	(6,025)	(11,494)	(16,677)
Gross profit (loss)	1,503	344	(256)	(583)
Advanced projects - Other	(8,817)	(4,013)	(34,874)	(6,635)
Income (loss) from investment in Minera Santa Cruz S.A.	758	(2,650)	2,149	(5,077)
Segment income (loss)	(10,485)	(12,564)	(44,413)	(30,412)
General and Administrative and other	(581)	(5,678)	(938)	(9,322)
Loss before income and mining taxes	(11,066)	(18,242)	(45,351)	(39,734)
Capital expenditures	8,078	11,128	16,512	21,452
United States Reportable Segment [Member]
Operating Segment Reporting
Revenue from gold and silver sales	12,596	21,683	34,334	60,919
Depreciation and depletion	(1,514)	(2,140)	(3,275)	(6,208)
Gross profit (loss)	(1,275)	790	(3,775)	1,335
Advanced projects - Other	(4)	(234)	(52)	(203)
Segment income (loss)	(2,334)	(876)	(7,574)	(2,755)
Capital expenditures	1,012	353	1,508	1,110
Canada
Operating Segment Reporting
Revenue from gold and silver sales	13,058	14,227	46,200	34,966
Depreciation and depletion	(2,799)	(3,885)	(8,219)	(10,469)
Gross profit (loss)	4,063	707	11,878	1,875
Advanced projects - Other	(30)	(871)	(227)	(2,058)
Segment income (loss)	1,300	(4,981)	4,595	(12,715)
Capital expenditures	4,080	10,775	11,633	20,342
Mexico Reportable Segment [Member]
Operating Segment Reporting
Revenue from gold and silver sales	334	1,219	1,643	5,690
Gross profit (loss)	(1,285)	(1,153)	(8,359)	(3,793)
Advanced projects - Other	(1,160)	(1,872)	(3,135)	(3,338)
Segment income (loss)	(2,445)	(3,021)	(11,494)	(7,145)
Capital expenditures	2,827		2,827
MSC
Operating Segment Reporting
Income (loss) from investment in Minera Santa Cruz S.A.	758	(2,650)	2,149	(5,077)
Segment income (loss)	758	(2,650)	2,149	(5,077)
Los Azules
Operating Segment Reporting
Advanced projects - Other	(7,623)	(1,036)	(31,460)	(1,036)
Segment income (loss)	(7,764)	(1,036)	(32,089)	(2,720)
Capital expenditures	159		544
Other
Operating Segment Reporting
Advanced projects - Other	(1,194)	(2,977)	(3,414)	(5,599)
Gold and silver sales
Operating Segment Reporting
Revenue from gold and silver sales	10,208	37,129	66,397	101,575
Product [Member]
Operating Segment Reporting
Production costs applicable to sales	(20,172)	(30,760)	(70,939)	(85,481)
Product [Member] | United States Reportable Segment [Member]
Operating Segment Reporting
Production costs applicable to sales	(12,357)	(18,753)	(34,834)	(53,376)
Product [Member] | Canada
Operating Segment Reporting
Production costs applicable to sales	(6,196)	(9,635)	(26,103)	(22,622)
Product [Member] | Mexico Reportable Segment [Member]
Operating Segment Reporting
Production costs applicable to sales	(1,619)	(2,372)	(10,002)	(9,483)
Exploration
Operating Segment Reporting
Production costs applicable to sales	(3,929)	(6,245)	(11,432)	(18,117)
Exploration | United States Reportable Segment [Member]
Operating Segment Reporting
Production costs applicable to sales	(1,055)	(1,432)	(3,747)	(3,887)
Exploration | Canada
Operating Segment Reporting
Production costs applicable to sales	(2,733)	(4,817)	(7,056)	(12,532)
Exploration | Mexico Reportable Segment [Member]
Operating Segment Reporting
Production costs applicable to sales		$ 4		(14)
Exploration | Los Azules
Operating Segment Reporting
Production costs applicable to sales	$ (141)		$ (629)	$ (1,684)