Note 2 - Business Segments and Sales of Products - Information About Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 30, 2021	Dec. 31, 2020
Net sales	$ 210,852	$ 136,925
Income (loss) from operations	38,449	(15,064)
Identifiable assets	2,655,077		$ 2,655,077	$ 2,667,724
Greens Creek [Member]
Net sales	98,409	53,833
Income (loss) from operations	44,600	4,117
Identifiable assets			609,612	610,360
Lucky Friday [Member]
Net sales	29,122	2,830
Income (loss) from operations	6,323	(8,120)
Identifiable assets			513,645	520,463
Casa Berardi [Member]
Net sales	72,911	46,172
Income (loss) from operations	9,117	(3,880)
Identifiable assets			683,103	694,522
San Sebastian [Member]
Net sales	173	9,927
Income (loss) from operations	(2,263)	679
Identifiable assets			41,238	42,617
Nevada Operations [Member]
Net sales	10,237	24,163
Income (loss) from operations	(3,140)	2,889
Identifiable assets			510,514	513,309
Other Segments [Member]
Income (loss) from operations	$ (16,188)	$ (10,749)
Identifiable assets			$ 296,965	$ 286,453