Note I - Stock Option Plans - Summary of Option Activity for Employees (Details) - Share-Based Payment Arrangement, Option [Member] - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Jan. 01, 2023
Number of options granted (in shares)	0
Share-Based Payment Arrangement, Employee [Member]
Number of options (in shares)	3,059,989
Weighted average exercise price, outstanding (in dollars per share)	$ 2.36
Weighted average remaining contractual life, outstanding (Year)	5 years 4 months 28 days	6 years 4 months 17 days
Aggregate intrinsic value, outstanding	$ 0
Number of options granted (in shares)	0
Weighted average exercise price, granted (in dollars per share)	$ 0
Number of options exercised (in shares)	0
Weighted average exercise price, exercised (in dollars per share)	$ 0
Number of options forfeited and expired (in shares)	(23,000)
Weighted average exercise price, forfeited or expired (in dollars per share)	$ 0
Number of options (in shares)	3,036,989	3,059,989
Weighted average exercise price, outstanding (in dollars per share)	$ 2.29	$ 2.36
Number of options exercisable (in shares)	1,732,084
Weighted average exercise price, exercisable (in dollars per share)	$ 2.21
Weighted average remaining contractual life, exercisable (Year)	4 years 4 months 2 days
Share-Based Payment Arrangement, Nonemployee [Member]
Number of options (in shares)	91,663
Weighted average exercise price, outstanding (in dollars per share)	$ 1.75
Weighted average remaining contractual life, outstanding (Year)	2 years 3 months	2 years 6 months 18 days
Aggregate intrinsic value, outstanding	$ 2,833		$ 1,083
Number of options granted (in shares)	8,333
Weighted average exercise price, granted (in dollars per share)	$ 0.89
Number of options exercised (in shares)	(8,333)
Weighted average exercise price, exercised (in dollars per share)	$ 0.75
Number of options (in shares)	91,663	91,663
Weighted average exercise price, outstanding (in dollars per share)	$ 1.76	$ 1.75
Number of options exercisable (in shares)	83,332
Weighted average exercise price, exercisable (in dollars per share)	$ 1.86
Weighted average remaining contractual life, exercisable (Year)	1 year 9 months 14 days
Weighted average remaining contractual life, granted (Year)	4 years 2 months 15 days
Aggregate intrinsic value, exercisable	$ 2,833