Note 11 - Income Taxes (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (8,000)		$ (69,000)
Income Tax Expense (Benefit), Total	$ 0	$ 0	456	$ 0
Maximum [Member]
Income Tax Expense (Benefit), Total			$ 1,000

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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