Note 11 - Business Segment Information - Components of Customer Sales Determined Based on the Location of Customers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net sales	$ 378,316	$ 348,967	$ 398,179
UNITED STATES
Net sales	260,683	246,913	275,290
Foreign Countries [Member]
Net sales	$ 117,633	$ 102,054	$ 122,889