Note 10 - Segment and Geographic Information - Summary of Current Segments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 25, 2021	Dec. 26, 2020
Net sales		$ 812,775	$ 887,214	$ 636,007
Profit (loss) for reportable segments			141,933	4,474
Gain (Loss) on Disposition of Business	[1]	(0)	70,815	(0)
Interest expense		(4,177)	(6,413)	(13,759)
Interest income		4,012	239	224
Gain (Loss) on Extinguishment of Debt, Total		(312)	(3,411)	268
Profit (loss) from continuing operations before taxes		126,715	192,344	(13,177)
Total depreciation and amortization		46,016	48,568	52,746
Capital expenditures		14,770	12,000	18,660
Total assets for reportable segments		$ 1,227,414	1,259,044	1,090,346
Discontinued operations				0
Corporate, Non-Segment [Member]
Corporate expenses			(10,819)	(4,384)
Total assets for reportable segments				55,492
Semiconductor Test and Inspection [Member]
Net sales			860,454	585,240
Profit (loss) for reportable segments			138,026	(2,497)
Total depreciation and amortization			48,129	51,548
Capital expenditures			11,954	18,616
Total assets for reportable segments				968,028
PCB Test [Member]
Net sales			26,760	50,767
Profit (loss) for reportable segments			3,907	6,971
Total depreciation and amortization			439	1,198
Capital expenditures			$ 46	44
Total assets for reportable segments				66,826
Semiconductor Test and Inspection and PCB Test [Member]
Total assets for reportable segments				$ 1,034,854

[1] On June 24, 2021 we completed the divestment of our PCB Test business. The divestment of this business did not qualify for presentation as discontinued operations and the results of the PCB Test business are included in continuing operations for all periods presented. See Note 14, “Business Divestitures and Discontinued Operations” for additional information on this transaction and financial statement presentation.