Inventories (Schedule Of Components Of Inventories) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Inventory, Net [Abstract]
Finished goods	$ 14,679	$ 13,935
Work-in-process	10,173	9,249
Raw materials	20,338	22,149
Stores, supplies and other	20,327	19,992
Total	$ 65,517	$ 65,325