Property, Plant And Equipment (Schedule Of Property, Plant And Equipment) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 40,167,000	$ 42,985,000
Less accumulated depreciation	(29,205,000)	(30,360,000)
Property, plant and equipment, net	10,962,239	12,624,730
Land [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	2,968,000	2,951,000
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	8,914,000	8,867,000
Machinery And Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	24,105,000	26,597,000
Furniture And Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	4,054,000	4,174,000
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 126,000	$ 396,000
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