Note 4 - Commitments, Contingencies and Obligations (Details) (USD $)	0 Months Ended	3 Months Ended	4 Months Ended	12 Months Ended	1 Months Ended		0 Months Ended		1 Months Ended	3 Months Ended	1 Months Ended
	Dec. 11, 2013	Mar. 31, 2015	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2014	Jul. 30, 2010	Feb. 04, 2015	Apr. 12, 2013	Aug. 31, 2012	Dec. 31, 2012	Jun. 30, 2011	Apr. 30, 2009
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Maximum Environmental Remediation Obligation				$ 2,500,000
Loss Contingency, Estimate of Possible Loss	1,000,000											177,500
Loss Contingency, Damages Sought, Value			5,000,000
Contractual Obligations		4,000,000
Commitments For Capital Lease Payments		22,700,000
Surety Bonds		68,900,000
Letters of Credit Outstanding, Amount				7,900,000	7,900,000
Loss Contingency, Number of Plaintiffs	4
Greens Creek [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Open Purchase Orders		500,000
Noncapital Costs		8,800,000
Lucky Friday [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Open Purchase Orders		2,200,000
Noncapital Costs		1,300,000
Casa Berardi [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Open Purchase Orders		800,000
Noncapital Costs		300,000
Joint Venture [Member] | Rio Grande Silver Inc And Emerald Mining And Leasing LLC [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Equity Method Investment, Ownership Percentage				70.00%	70.00%
Minimum [Member] | United Steel Workers, Local 5114 [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Loss Contingency, Damages Sought, Value		0
Minimum [Member] | Johnny M Mine Area near San Mateo, New Mexico [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Estimated Response Costs					0
Maximum [Member] | United Steel Workers, Local 5114 [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Loss Contingency, Damages Sought, Value		10,000,000
Maximum [Member] | Johnny M Mine Area near San Mateo, New Mexico [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Estimated Response Costs					221,000,000
Costs Incurred By The EPA [Member] | Gilt Edge Mine Superfund Site [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Incurred Response Costs						225,000,000
United Steel Workers, Local 5114 [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Litigation Settlement, Amount							(13,000)
Senior Notes [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Proceeds from Issuance of Debt								500,000,000
Debt Instrument, Interest Rate, Stated Percentage								6.875%
Debt Instrument, Increase (Decrease), Net				6,500,000
Johnny M Mine Area near San Mateo, New Mexico [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Payment Of Response Costs									1,100,000	1,100,000
Estimated Response Costs					5,600,000
Liability for Remediation					5,600,000
Carpenter Snow Creek Superfund Site, Cascade County, Montana [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Estimated Response Costs											4,500,000
Estimated Future Response Cost											100,000,000
Gilt Edge Mine Superfund Site [Member] | Third Party Operator of Mine [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Litigation Settlement, Amount						26,000,000
Gilt Edge Mine Superfund Site [Member] | Third Mining Company [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Litigation Settlement, Amount						4,200,000
Gilt Edge Mine Superfund Site [Member]
Note 4 - Commitments, Contingencies and Obligations (Details) [Line Items]
Alleged Potential Response Costs						$ 225,000,000