Note 11. Business Segments and Significant Customers (Detail) - Information About Reportable Segments (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net sales from continuing operations to unaffiliated customers:
Net Sales From Continuing Operations To Unaffiliated Customers	$ 477,634	$ 418,813	$ 312,548
Income (loss) from operations:
Income (Loss) From Operations	197,645	(51,555)	75,272
Capital additions (including non-cash additions):
Capital Additions (Including Non-Cash Additions)	137,385	74,739	33,540
Depreciation, depletion and amortization from continuing operations:
Depreciation, Depletion And Amortization From Continuing Operations	47,066	60,011	62,837
Other significant non-cash items from continuing operations:
Other Significant Non-Cash Items From Continuing Operations	33,810	80,533	(3,691)
Identifiable assets:
Identifiable Assets	1,396,090	1,382,493	1,046,784
Greens Creek [Member]
Net sales from continuing operations to unaffiliated customers:
Net Sales From Continuing Operations To Unaffiliated Customers	342,906	313,318	229,318
Income (loss) from operations:
Income (Loss) From Operations	181,116	138,973	79,329
Capital additions (including non-cash additions):
Capital Additions (Including Non-Cash Additions)	41,657	18,280	17,520
Depreciation, depletion and amortization from continuing operations:
Depreciation, Depletion And Amortization From Continuing Operations	41,013	51,671	52,909
Other significant non-cash items from continuing operations:
Other Significant Non-Cash Items From Continuing Operations	2,326	17,829	2,974
Identifiable assets:
Identifiable Assets	729,289	740,573	771,433
Lucky Friday [Member]
Net sales from continuing operations to unaffiliated customers:
Net Sales From Continuing Operations To Unaffiliated Customers	134,728	105,495	83,230
Income (loss) from operations:
Income (Loss) From Operations	75,608	48,639	27,146
Capital additions (including non-cash additions):
Capital Additions (Including Non-Cash Additions)	60,454	54,370	15,990
Depreciation, depletion and amortization from continuing operations:
Depreciation, Depletion And Amortization From Continuing Operations	6,053	8,340	9,928
Other significant non-cash items from continuing operations:
Other Significant Non-Cash Items From Continuing Operations	14	5,053	22
Identifiable assets:
Identifiable Assets	213,285	170,928	116,797
All Other Segments [Member]
Income (loss) from operations:
Income (Loss) From Operations	(59,079)	(239,167)	(31,203)
Capital additions (including non-cash additions):
Capital Additions (Including Non-Cash Additions)	35,274	2,089	30
Other significant non-cash items from continuing operations:
Other Significant Non-Cash Items From Continuing Operations	31,470	57,651	(6,687)
Identifiable assets:
Identifiable Assets	$ 453,516	$ 470,992	$ 158,554