NATURE OF OPERATIONS AND BASIS OF PRESENTATION (Details)	9 Months Ended
	Sep. 30, 2021
Nature of operations and recent accounting pronouncements
Ownership interests in various mines (as a percent)	100.00%
Ownership interest (as a percent)	49.00%
Minera Andes Inc.
Nature of operations and recent accounting pronouncements
Ownership interest (as a percent)	100.00%
Minera Santa Cruz S.A. | Equity Method Investment
Nature of operations and recent accounting pronouncements
Ownership interest (as a percent)	49.00%
Los Azules Copper Project | Equity Method Investment
Nature of operations and recent accounting pronouncements
Ownership interest (as a percent)	82.00%