Note A - Summary of Significant Accounting Policies - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Amortized Cost	$ 24,993	$ 34,164
Fair Value	24,863	34,190
Gross Unrealized Gains	22	31
Gross Unrealized Losses	152	5
Fixed Rate Municipal Bonds [Member]
Amortized Cost	11,460	8,737
Fair Value	11,405	8,763
Gross Unrealized Gains	0	31
Gross Unrealized Losses	58	5
Certificates of Deposit [Member]
Amortized Cost	9,895
Fair Value	9,820
Gross Unrealized Gains	22
Gross Unrealized Losses	94
Variable Rate Demand Obligation [Member]
Amortized Cost	3,638	25,427
Fair Value	$ 3,638	$ 25,427

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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