Note 10 - Provision for Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020
Taxes Payable, Total	$ 387	$ 387
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	48	48
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	0
Foreign Tax Authority [Member]
Tax Credit Carryforward, Amount	95
Domestic Tax Authority [Member]
Increase (Decrease) in Income Taxes Receivable	631	180
State and Local Jurisdiction [Member]
Increase (Decrease) in Income Taxes Receivable	108
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable		$ 123
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	244
Tax Credit Carryforward, Valuation Allowance	23
Tax Credit Carryforward, Amount, Net of Valuation Allowance	$ 221