Note 4 - Environmental and Reclamation Activities (Details) - Liabilities Accrued for Reclamation and Closure Costs (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating properties:
Accrued reclamation and closure costs	$ 57,250	$ 105,191	$ 113,215	$ 153,811
Reclamation and closure costs, current	(1,631)	(58,425)
Reclamation and closure costs, long-term	55,619	46,766
Greens Creek [Member] | Operating Properties [Member]
Operating properties:
Accrued reclamation and closure costs	39,237	34,530
Lucky Friday [Member] | Operating Properties [Member]
Operating properties:
Accrued reclamation and closure costs	1,069	919
Casa Berardi [Member] | Operating Properties [Member]
Operating properties:
Accrued reclamation and closure costs	6,233	7,795
Coeur d'Alene Basin [Member] | Non-operating Properties [Member]
Operating properties:
Accrued reclamation and closure costs		55,499
Johnny M [Member] | Non-operating Properties [Member]
Operating properties:
Accrued reclamation and closure costs	5,830	303
Republic [Member] | Non-operating Properties [Member]
Operating properties:
Accrued reclamation and closure costs	1,389	3,023
All Other Sites [Member] | Non-operating Properties [Member]
Operating properties:
Accrued reclamation and closure costs	$ 3,492	$ 3,122