Note 6 - Acquisitions - Proforma Revenue and Earnings (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Revenues	$ 51,595	$ 50,812
Operating income	$ 1,654	$ 1,720
Diluted net income per share (in dollars per share)		$ 0.09
TKE [Member]
Revenues		$ 52,632
Operating income		$ 2,026
Diluted net income per share (in dollars per share)		$ 0.10