Note 11 - Business Segments and Significant Customers (Tables)

12 Months Ended

Dec. 31, 2014

Segment Reporting [Abstract]

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Year Ended December 31,
	2014			2013			2012
Greens Creek		49.0	%		68.8	%		100.0	%
Lucky Friday		17.9	%		11.6	%		—	%
Casa Berardi		33.1	%		19.6	%		—	%
		100	%		100	%		100	%

Schedule of Segment Reporting Information, by Segment [Table Text Block]

	2014			2013			2012
Net sales to unaffiliated customers:
Greens Creek	$	245,175		$	263,263		$	320,895
Lucky Friday		89,757			44,204			248
Casa Berardi		165,849			75,122			—
	$	500,781		$	382,589		$	321,143
Income (loss) from operations:
Greens Creek	$	39,758		$	62,178		$	138,245
Lucky Friday		21,502			(3,563	)		(25,179	)
Casa Berardi		11,828			(15,708	)		—
Other		(51,460	)		(75,301	)		(75,200	)
	$	21,628		$	(32,394	)	$	37,866
Capital additions (including non-cash additions):
Greens Creek	$	31,476		$	57,119		$	62,184
Lucky Friday		52,193			55,902			55,998
Casa Berardi		48,615			41,425			—
Other		18,801			8,162			11,760
	$	151,085		$	162,608		$	129,942
Depreciation, depletion and amortization:
Greens Creek	$	63,505		$	55,265		$	43,522
Lucky Friday		9,431			7,833			—
Casa Berardi		38,198			18,030			—
	$	111,134		$	81,128		$	43,522
Other significant non-cash items:
Greens Creek	$	2,807		$	1,961		$	4,037
Lucky Friday		72			96			92
Casa Berardi		847			474			—
Other		506			1,512			33,922
	$	4,232		$	4,043		$	38,051
Identifiable assets:
Greens Creek	$	704,121		$	744,027		$	741,666
Lucky Friday		356,482			313,793			226,196
Casa Berardi		800,961			821,058			—
Other		400,500			353,241			410,428
	$	2,262,064		$	2,232,119		$	1,378,290

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]

	2014		2013		2012
United States	$	22,200	$	22,361	$	25,438
Canada		295,027		170,632		34,441
Japan		58,466		50,039		70,371
Korea		70,548		86,035		120,106
China		53,067		50,479		72,133
Total, excluding gains/losses on forward contracts	$	499,308	$	379,546	$	322,489

Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]

	2014		2013
United States	$	1,081,699	$	1,053,374
Canada		749,810		738,172
Mexico		55		55
	$	1,831,564	$	1,791,601

Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]

	Year Ended December 31,
	2014			2013			2012
Teck Metals Ltd.		25.8	%		25.0	%		10.7	%
Korea Zinc		14.1	%		22.5	%		37.2	%
Trafigura AG		7.0	%		8.8	%		22.4	%
MS Zinc		5.9	%		7.5	%		12.3	%
CIBC		17.0	%		10.9	%		—	%
Mitsui		15.8	%		8.4	%		—	%