Note 2 - Revenue Recognition - Revenue Disaggregated by the Major Types of Goods and Services Sold (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net sales	$ 50,260	$ 49,394	$ 51,399	$ 47,328	$ 50,697	$ 47,808	$ 49,019	$ 42,931	$ 198,381	$ 190,455	$ 147,843
Product [Member]
Net sales									193,016	183,186	146,275
Tooling and Machinery [Member]
Net sales									2,730	4,302	1,181
Engineering and Development [Member]
Net sales									$ 2,635	$ 2,967	$ 387