Note 2 - Investments and Restricted Cash (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Note 2 - Investments and Restricted Cash (Details) [Line Items]
Long-term Investments	$ 2,672	$ 2,672			$ 2,672		$ 4,920
Available-for-sale Securities, Amortized Cost Basis	4,400	4,400			4,400		7,300
Other than Temporary Impairment Losses, Investments			$ 2,800
Payments to Acquire Investments			$ 900		947
Unrealized Gain (Loss) on Investments		(117)		$ (608)	(2,960)	$ 80
Restricted Investments	1,000	1,000			1,000		$ 900
Non-Current Investments Held Having Net Loss Position [Member]
Note 2 - Investments and Restricted Cash (Details) [Line Items]
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(1,700)	$ (1,700)			$ (1,700)
Revett Mining Company, Inc. [Member]
Note 2 - Investments and Restricted Cash (Details) [Line Items]
Increase (Decrease) in Cost Basis of Investments	(500)
Unrealized Gain (Loss) on Investments	$ (200)