Note 10. Derivative Instruments (Tables)

12 Months Ended

Dec. 31, 2011

Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]

December 31, 2011	Metric tonnes under contract				Average price per pound
	Zinc		Lead		Zinc		Lead
Contracts on provisional sales
2012 settlements		9,600		2,600	$	0.86	$	0.89
Contracts on forecasted sales
2012 settlements		20,500		15,900	$	1.12	$	1.12
2013 settlements		8,275		11,150	$	1.14	$	1.17

December 31, 2010	Metric tonnes under contract				Average price per pound
	Zinc		Lead		Zinc		Lead
Contracts on provisional sales
2011 settlements		11,575		3,925	$	1.05	$	1.11
Contracts on forecasted sales
2011 settlements		19,475		15,550	$	0.96	$	0.96
2012 settlements		21,475		15,000	$	1.11	$	1.11

Schedule of Interest Rate Derivatives [Table Text Block]

Loss reclassified from accumulated other comprehensive loss to interest expense	$	1,967
Loss recognized in interest expense related to the ineffective portion	213