Note 5 - Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, plant and equipment, gross	$ 74,421	$ 72,465
Accumulated depreciation and amortization	(47,577)	(44,932)
	26,844	27,533
Land [Member]
Property, plant and equipment, gross	3,635	4,485
Buildings Improvements and Leaseholds [Member]
Property, plant and equipment, gross	18,192	19,140
Machinery, Equipment and Fixtures [Member]
Property, plant and equipment, gross	$ 52,594	$ 48,840