Note 1 - Summary of Significant Accounting Policies (Details Textual)			3 Months Ended		6 Months Ended
	Oct. 01, 2021 USD ($)	Jun. 24, 2021	Jun. 25, 2022 USD ($) shares	Jun. 26, 2021 USD ($) shares	Jun. 25, 2022 USD ($) shares	Jun. 26, 2021 USD ($) shares	Dec. 25, 2021 USD ($)
Accounts Receivable, Allowance for Credit Loss, Ending Balance			$ 200,000		$ 200,000		$ 300,000
Capitalized Computer Software, Gross			14,000,000.0		14,000,000.0		13,500,000
Capitalized Computer Software, Amortization			500,000	$ 300,000	$ 956,000	$ 748,000
Number of Operating Segments					3
Number of Reportable Segments		2			1
Goodwill and Intangible Asset Impairment, Total	$ 0
Amortization of Debt Issuance Costs			100,000	200,000	$ 200,000	500,000
Foreign Currency Transaction Gain (Loss), Realized			$ 1,500,000	$ (25,000)	$ 2,600,000	$ (300,000)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares			351,000	240,000	288,000	120,000
Revenue, Remaining Performance Obligation, Amount			$ 7,400,000		$ 7,400,000
Provision for Doubtful Accounts					0
Contract with Customer, Asset, after Allowance for Credit Loss, Total			0		0
Deferred Revenue, Total			18,600,000		18,600,000		21,900,000
Deferred Profit			10,406,000		10,406,000		13,208,000	[1]
Deferred Profit Long-term			5,800,000		5,800,000		6,100,000
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total			$ (49,385,000)		$ (49,385,000)		$ (27,262,000)	[1]
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Asset, Useful Life (Year)			7 years		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

[1] Derived from December 25, 2021 audited financial statements