Note G - Cash, Cash Equivalents And Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Apr. 04, 2021	Dec. 31, 2020
Amortized Cost	$ 51,959	$ 68,785
Fair Value	52,092	68,981
Gross Unrealized Gains	133	196
Gross Unrealized Losses	0	0
Nontaxable Municipal Bonds [Member]
Amortized Cost	26,309	42,817
Fair Value	26,442	43,013
Gross Unrealized Gains	133	196
Gross Unrealized Losses	0	0
Variable Rate Demand Obligation [Member]
Amortized Cost	25,650	25,968
Fair Value	25,650	25,968
Gross Unrealized Gains	0	0
Gross Unrealized Losses	$ 0	$ 0

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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