Note 5 - Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property, plant and equipment, gross	$ 286,789	$ 281,239
Less accumulated depreciation	(173,323)	(164,168)
Property, plant and equipment, net	113,466	117,071
Land [Member]
Property, plant and equipment, gross	3,879	4,187
Building [Member]
Property, plant and equipment, gross	106,393	106,437
Machinery and Equipment [Member]
Property, plant and equipment, gross	$ 176,517	$ 170,615

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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