Note H - Income Taxes - Reconciliation of Statutory Rate to Effective Rate (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statutory rate	21.00%	21.00%	21.00%
State tax, net of federal benefit	0.00%	2.30%	1.70%
Research and development credit	(2.10%)	(2.00%)	(1.00%)
Adjustment for prior year estimates	1.20%	0.10%	(0.10%)
Tax exempt interest and dividends	(0.10%)	(0.10%)	(0.10%)
Other	0.20%	(0.30%)	0.20%
Effective rate	20.20%	21.00%	21.70%