INCOME AND MINING TAXES - Deferred Income Tax Recovery (Expense) and Net Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax recovery (expense)
United States	$ 387	$ 817	$ 2,420
Foreign	6,928	573	1,424
Deferred tax benefit	7,315	1,390	3,844
Net income (loss) before tax:
United States	(24,808)	(127,524)	(22,319)
Foreign	(39,391)	(26,191)	(41,272)
Loss before income and mining taxes	$ (64,199)	$ (153,715)	$ (63,591)