Note 4 - Commitments, Contingencies and Obligations (Details) (USD $)	0 Months Ended	1 Months Ended				3 Months Ended						0 Months Ended	3 Months Ended					1 Months Ended
	Dec. 11, 2013	Aug. 30, 2014	Sep. 30, 2013	Aug. 31, 2012	Jun. 30, 2011	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2012	Jan. 06, 2014	Apr. 30, 2013	Apr. 30, 2009	Jan. 06, 2014 Subsequent Event [Member]	Mar. 31, 2014 Casa Berardi [Member]	Mar. 31, 2014 Greens Creek [Member]	Mar. 31, 2014 Lucky Friday [Member]	Jan. 06, 2014 Prior Senior Notes [Member]	Mar. 31, 2014 Joint Venture [Member] Rio Grande Silver Inc And Emerald Mining And Leasing LLC [Member]	Apr. 30, 2013 Costs Incurred By The EPA [Member]	Mar. 31, 2014 Minimum [Member]	Mar. 31, 2014 Maximum [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Equity Method Investment, Ownership Percentage																	70.00%
Maximum Environmental Remediation Obligation						$ 2,500,000
Loss Contingency, Estimate of Possible Loss	1,000,000									191,000,000	177,500								0	10,000,000
Payment Of Response Costs				1,100,000				1,100,000
Other Accrued Liabilities, Noncurrent						300,000
Estimated Response Costs					4,500,000
Estimated Future Response Cost					100,000,000
Incurred Response Costs																		191,000,000
Loss Contingency, Damages Sought, Value			5,000,000
Proceeds from Issuance of Debt												500,000,000
Debt Instrument, Interest Rate, Stated Percentage						6.875%			6.875%							6.875%
Contractual Obligations						5,900,000
Open Purchase Orders													800,000	1,300,000	1,400,000
Noncapital Costs													400,000	300,000	500,000
Commitments For Capital Lease Payments						23,600,000
Environmental Expense and Liabilities		55,400,000				933,000	591,000
Letters of Credit Outstanding, Amount						$ 1,300,000
Loss Contingency, Number of Plaintiffs	4