Property, Plant And Equipment (Schedule Of Property, Plant And Equipment) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 42,985,000	$ 48,527,000
Less accumulated depreciation	(30,360,000)	(32,807,000)
Property, plant and equipment, net	12,624,730	15,719,403
Land [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	2,951,000	2,951,000
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	8,867,000	9,112,000
Machinery And Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	26,597,000	31,394,000
Furniture And Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	4,174,000	4,811,000
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 396,000	$ 259,000
Minimum [Member] | Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum [Member] | Machinery And Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum [Member] | Furniture And Fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Maximum [Member] | Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	40 years
Maximum [Member] | Machinery And Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Maximum [Member] | Furniture And Fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years