Inventories (Components Of Inventories) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Inventory Disclosure [Abstract]
Adjustments to inventory value	$ 0	$ 0
Metals inventory
Raw ore	3,669,000		3,505,000
Concentrate and in-process	68,624,000		51,498,000
Finished goods	89,091,000		74,942,000
Metals inventory	161,384,000		129,945,000
Materials and supplies	25,087,000		23,263,000
Total inventory	$ 186,471,000		$ 153,208,000