Note 7 - Property, Plant and Equipment - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Property, plant and equipment, gross	$ 165,896	$ 163,804
Accumulated depreciation	(123,426)	(119,872)
Property, plant and equipment, net	42,470	43,932
Land [Member]
Property, plant and equipment, gross	1,426	2,251
Building and Building Improvements [Member]
Property, plant and equipment, gross	29,341	30,119
Machinery and Equipment [Member]
Property, plant and equipment, gross	128,766	126,747
Construction in Progress [Member]
Property, plant and equipment, gross	$ 6,363	$ 4,687

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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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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