Note 3 - Income and Mining Taxes - Major Components of Income Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Domestic	$ (3,036)	$ (253)	$ (5,313)	$ (985)
Foreign	(826)	(1,650)	(3,112)	(3,719)
Total current income and mining tax provision	(3,862)	(1,903)	(8,425)	(4,704)
Domestic	4,117	1,866	4,436	3,116
Foreign	4,587	(589)	4,197	2,024
Total deferred income and mining tax benefit	8,704	1,277	8,633	5,140
Total income and mining tax benefit (provision)	$ 4,842	$ (626)	$ 208	$ 436