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OPERATING SEGMENT REPORTING - Geographic information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Operating Segment Reporting
Long-lived Assets	$ 440,478		$ 440,315
Revenue	25,542	$ 23,740
Investment in MSC	89,841		90,961
Total which excludes Company's ROU office lease asset	400
Minera Santa Cruz S.A. [Member]
Operating Segment Reporting
Revenue	39,207	53,303
Investment in MSC	89,841		90,961	$ 108,326
UNITED STATES
Operating Segment Reporting
Long-lived Assets	35,865		37,877
Revenue	11,742	12,893
Canada
Operating Segment Reporting
Long-lived Assets	96,448		93,294
Revenue	12,896	8,561
MEXICO
Operating Segment Reporting
Long-lived Assets	26,558		26,561
Revenue	904	$ 2,286
ARGENTINA
Operating Segment Reporting
Long-lived Assets	281,607		282,583
ARGENTINA \| Minera Santa Cruz S.A. [Member]
Operating Segment Reporting
Investment in MSC	$ 89,800		$ 90,900