Note F - Long-term Debt (Details Textual) - USD ($)					12 Months Ended
	Dec. 21, 2021	Jun. 10, 2021	Apr. 14, 2020	Apr. 17, 2017	Dec. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Letters of Credit Outstanding, Amount					$ 0
Interest Expense, Debt, Total					300,000	$ 500,000
Gain (Loss) on Extinguishment of Debt, Total					$ (0)	10,000,000
Texas Capital Bank [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage					0.25%
Debt Instrument, Interest Rate, Effective Percentage					6.10%
Standby Letters of Credit [Member]
Long-Term Line of Credit, Total					$ 800,000	1,100,000
Revolving Credit Facility [Member] | Bloomberg Short-Term Bank Yield Index Rate [Member] | Texas Capital Bank [Member]
Debt Instrument, Basis Spread on Variable Rate	2.25%
New Credit Facility [Member]
Long-Term Line of Credit, Total					0.0	5,000,000.0
Line of Credit Facility, Remaining Borrowing Capacity					$ 24,200,000
New Credit Facility [Member] | Revolving Credit Facility [Member] | Texas Capital Bank [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 25,000,000
Debt Instrument, Term (Year)	3 years
Texas Capital Credit Facility [Member]
Long-Term Line of Credit, Total						5,000,000.0
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage				0.50%
Line of Credit Facility, Collateral Fees, Percentage				0.50%
Interest Expense, Debt, Total						400,000
Repayments of Long-term Lines of Credit						$ 12,100,000
Texas Capital Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate				1.95%
Texas Capital Credit Facility [Member] | Prime Rate [Member]
Debt Instrument, Basis Spread on Variable Rate				0.75%
Texas Capital Credit Facility [Member] | Standby Letters of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity				$ 5,000,000.0
Texas Capital Credit Facility [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity				$ 20,000,000.0
Paycheck Protection Program CARES Act [Member]
Proceeds from Notes Payable, Total			$ 10,000,000.0
Notes Payable, Total							$ 10,000,000.0
Gain (Loss) on Extinguishment of Debt, Total		$ 10,000,000.0