Note 1 - Summary of Significant Accounting Policies (Details Textual) $ in Thousands			12 Months Ended
	Oct. 01, 2022 USD ($)	Jun. 24, 2021	Dec. 31, 2022 USD ($) shares	Dec. 25, 2021 USD ($) shares	Dec. 26, 2020 USD ($) shares
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares			261,000	180,000	113,000
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense			$ 7,200	$ 7,100	$ 8,100
Gain (Loss) on Disposition of Property Plant Equipment, Total			(0)	(0)	4,495
Depreciation, Total			12,800	13,200	14,000
Capitalized Computer Software, Gross			14,700	13,500
Capitalized Computer Software, Amortization			$ 2,060	$ 1,644	1,191
Number of Operating Segments				3
Number of Reportable Segments		2	1	1
Goodwill and Intangible Asset Impairment, Total	$ 0
Revenue, Remaining Performance Obligation, Amount			$ 7,100	$ 7,700
Provision for Doubtful Accounts				0
Contract with Customer, Asset, after Allowance for Credit Loss, Total				0
Contract with Customer, Liability, Total			16,100	21,900
Deferred Profit			8,022	13,208
Deferred Profit Long-term			5,500	6,100
Amortization of Debt Issuance Costs			300	600	1,200
Foreign Currency Transaction Gain (Loss), Realized			1,600	400
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total			(40,012)	(27,262)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax			$ (18,000)	$ (23,000)
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Asset, Useful Life (Year)			7 years
Minimum [Member]
Standard Product Warranty Term (Month)			12 months
Maximum [Member]
Standard Product Warranty Term (Month)			36 months
Building [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)			30 years
Building [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)			40 years
Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)			5 years
Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)			15 years
Machinery, Equipment and Software [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)			3 years
Machinery, Equipment and Software [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)			10 years
Xcerra [Member]
Inventory Write-down					$ 2,100