Note 6. Business Segments (Detail) - Information About Reportable Segments (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Net sales from operations to customers:
Net sales from operations to customers	$ 120,543	$ 115,847	$ 374,767	$ 284,353
Income (loss) from operations:
Income (loss) from operations	43,489	41,501	166,015	81,747
Greens Creek [Member]
Net sales from operations to customers:
Net sales from operations to customers	77,031	88,843	260,650	212,326
Income (loss) from operations:
Income (loss) from operations	37,098	39,493	140,661	83,279
Lucky Friday [Member]
Net sales from operations to customers:
Net sales from operations to customers	43,512	27,004	114,117	72,027
Income (loss) from operations:
Income (loss) from operations	27,662	12,550	68,170	30,856
Other Segment Income(Loss) [Member]
Income (loss) from operations:
Income (loss) from operations	$ (21,271)	$ (10,542)	$ (42,816)	$ (32,388)