Note 10 - Stock Compensation Plans - Summary of Option Activity (Details) - Share-Based Payment Arrangement, Option [Member] - $ / shares	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Outstanding (in shares)	195,936
The Option Plan and Stock Incentive Plan [Member]
Outstanding, number of shares (in shares)	195,936	233,136	233,136
Outstanding, weighted average (in dollars per share)	$ 11.24	$ 10.96	$ 10.96
Outstanding at the beginning of the period (Year)	3 years 8 months 12 days	4 years 1 month 6 days	3 years 6 months	4 years 2 months 12 days
Granted, number of shares (in shares)	0	0
Granted, weighted average exercise price (in dollars per share)	$ 0	$ 0
Exercised, number of shares (in shares)	(23,000)	(1,000)
Exercised, weighted average exercise price (in dollars per share)	$ 8.10	$ 13.30
Forfeited, number of shares (in shares)	0	0
Forfeited, weighted average exercise price (in dollars per share)	$ 0	$ 0
Outstanding (in shares)	172,936	232,136	195,936	233,136
Outstanding, weighted average (in dollars per share)	$ 11.66	$ 10.95	$ 11.24	$ 10.96
Exercisable at end of period (in shares)	147,009	179,081
Exercisable at end of period, weighted average exercise price (in dollars per share)	$ 10.62	$ 10.26
Exercisable at end of period, weighted average remaining contractual life (Year)	6 years 6 months	5 years 7 months 6 days