Inventories (Schedule Of Components Of Inventories) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Inventory, Net [Abstract]
Finished goods	$ 21,442	$ 16,215
Work-in-process	10,695	8,590
Raw materials	32,061	23,733
Stores, supplies and other	18,228	17,531
Total	$ 82,426	$ 66,069