Note 7. Commitments and Contingencies (Detail) (USD $)	1 Months Ended				3 Months Ended	12 Months Ended				36 Months Ended
	Oct. 31, 2011	Jun. 30, 2011	Mar. 31, 2010	Jan. 31, 2010	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2007	Dec. 31, 2011	Sep. 30, 2011	Sep. 08, 2011
Environmental Litigation And Related Claims												$ 264,400,000
Payments for Legal Settlements	168,000,000				1
Surety Bonds	96,400,000							96,400,000
Payments Under Consent Decree	168,000,000
Proceeds from Warrant Exercises (in Dollars)	1,000,000						5,786,000	53,093,000		10,500,000
Superfund Rate						0.74%	0.69%
Accrual for Environmental Loss Contingencies											95,100,000
Proceeds from Insurance Settlement, Operating Activities									7,200,000
Maximum Environmental Remediation Obligation							2,500,000
Administrative Penalty							177,500
Incurred Response Costs			5,300,000	91,000,000
Estimated Future Response Cost		100,000,000		72,000,000
Contribution And Cost Recovery				9,000,000
Other Accrued Liabilities, Noncurrent					2,040,000		2,040,000			2,040,000
Estimated Response Costs		4,500,000	2.7
Contractual Obligations		9.3
Commitments For Capital Lease Payments					10,800,000		10,800,000			10,800,000
Letters of Credit Outstanding, Amount		600,000
Annual Maintenance Fee		600,000
Johnny M Site [Member]
Payments to Acquire Land				1,875,000
Non-Capital Costs [Member]
Contractual Obligations		0.01
Warrants Minimum Exercise Price [Member]
Investment Warrants, Exercise Price (in Dollars per share)	$ 2.44
Greens Creek [Member]
Accounts Payable, Other					1,875,000		1,875,000			1,875,000
Open Purchase Orders					9.9		9.9			9.9
Noncapital Costs							600,000
Payment Due By October 8, 2012 [Member]
Payments for Legal Settlements	25,000,000
Payment Due By October 8, 2013 [Member]
Payments for Legal Settlements	15,000,000
Payment Due By August 2014 [Member]
Payments for Legal Settlements	55,400,000
Lucky Friday [Member]
Accounts Payable, Other					165,000,000,000		165,000,000,000			165,000,000,000
Open Purchase Orders					0.1		0.1			0.1
Noncapital Costs							$ 100,000
Warrants Maximum Exercise Price [Member]
Investment Warrants, Exercise Price (in Dollars per share)	$ 2.49