Inventories (Schedule Of Inventories) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventory, Net [Abstract]
Finished goods	$ 13,935	$ 17,559
Work-in-process	9,249	10,089
Raw materials	22,149	25,227
Stores, supplies and other	19,992	21,433
Total	$ 65,325	$ 74,308