Note 4 - Supplemental Balance Sheet Information - Components of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, plant and equipment, gross	$ 91,423	$ 88,070
Less – Accumulated depreciation	(68,218)	(65,220)
Property, plant and equipment, net	23,205	22,850
Land [Member]
Property, plant and equipment, gross	1,273	1,273
Building and Building Improvements [Member]
Property, plant and equipment, gross	15,442	15,393
Machinery and Equipment [Member]
Property, plant and equipment, gross	63,780	61,048
Furniture and Fixtures [Member]
Property, plant and equipment, gross	2,588	2,235
Computer Equipment [Member]
Property, plant and equipment, gross	7,579	6,894
Construction in Progress [Member]
Property, plant and equipment, gross	$ 761	$ 1,227

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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