Note 2 - Business Segments and Sales of Products - Information About Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Net sales	$ 217,983	$ 166,355	$ 428,835	$ 303,280
Income (loss) from operations	26,462	10,551	64,911	(4,513)
Identifiable assets	2,671,238		2,671,238		$ 2,667,724
Greens Creek [Member]
Net sales	113,763	84,890	212,172	138,724
Income (loss) from operations	56,433	26,707	101,033	30,823
Identifiable assets	601,521		601,521		610,360
Lucky Friday [Member]
Net sales	39,645	11,455	68,767	14,285
Income (loss) from operations	11,737	(5,218)	18,060	(13,338)
Identifiable assets	513,189		513,189		520,463
Casa Berardi [Member]
Net sales	56,122	50,005	129,033	96,177
Income (loss) from operations	(3,200)	3,204	5,917	(676)
Identifiable assets	679,182		679,182		694,522
San Sebastian [Member]
Net sales	3	4,934	176	14,860
Income (loss) from operations	(961)	(859)	(3,224)	(180)
Identifiable assets	40,190		40,190		42,617
Nevada Operations [Member]
Net sales	8,450	15,071	18,687	39,234
Income (loss) from operations	(20,341)	(1,545)	(23,481)	1,344
Identifiable assets	499,583		499,583		513,309
Other Segments [Member]
Income (loss) from operations	(17,206)	$ (11,738)	(33,394)	$ (22,486)
Identifiable assets	$ 337,573		$ 337,573		$ 286,453