Note 14 - Segment Information - Revenues by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Revenues	$ 32,652	$ 50,705	$ 77,685	$ 102,300
UNITED STATES
Revenues	26,989	44,244	66,165	89,546
CANADA
Revenues	3,641	4,500	7,643	9,088
PUERTO RICO
Revenues	1,383	1,209	2,585	2,412
SERBIA
Revenues	$ 639	$ 752	$ 1,292	$ 1,254