Note D - Fair Values of Financial Instruments - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 20, 2021	Dec. 26, 2020	Mar. 21, 2020
Cash and cash equivalents	$ 5,879	$ 3,505	$ 6,167
Long-term debt	46,907	30,073
Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	5,879	3,505	$ 6,167
Fair Value, Inputs, Level 2 [Member]
Long-term debt	$ 46,907	$ 30,073

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant