Property, Plant And Equipment (Schedule Of Property, Plant And Equipment) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 24,667,000	$ 27,030,000
Less accumulated depreciation	(16,429,000)	(18,183,000)
Property, plant and equipment, net	8,238,089	8,847,091
Land [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	2,965,000	2,965,000
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	8,727,000	8,782,000
Machinery And Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	9,347,000	11,406,000
Furniture And Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 3,628,000	3,750,000
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment		$ 127,000
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