Property, Plant And Equipment (Schedule Of Property, Plant And Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 697,027	$ 659,825
Less accumulated depreciation	(485,549)	(473,159)
Property, plant and equipment, Net	211,478	186,666
Land [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	5,867	5,867
Buildings And Building Improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	79,178	76,139
Machinery And Equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	542,034	506,652
Furniture And Fixtures [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	11,430	10,035
Vehicles [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	1,099	1,125
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	54,272	42,288
Construction In Progress[Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 3,147	$ 17,719