Note 10 - Segment and Geographic Information - Summary of Current Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 26, 2022	Mar. 27, 2021
Net sales	$ 197,757	$ 225,488
Profit (loss) for reportable segments		39,056
Gain (Loss) on Disposition of Business	(0)	(115)
Interest expense	(981)	(2,575)
Interest income	111	50
Gain (Loss) on Extinguishment of Debt, Total	(104)	(1,761)
Income from operations before taxes	$ 27,863	31,182
Corporate, Non-Segment [Member]
Corporate expenses		(3,473)
Semiconductor Test and Inspection [Member]
Net sales		212,406
Profit (loss) for reportable segments		36,627
PCB Test [Member]
Net sales		13,082
Profit (loss) for reportable segments		$ 2,429