Note 7 - Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($)	9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Outstanding (in shares)	67,000	417,000	417,000
Outstanding, grant date weighted-average exercise price (in dollars per share)	$ 2.72	$ 2.79	$ 2.79
Outstanding, weighted average remaining contractual life (Year)		10 months 24 days	3 years 3 months 29 days	1 year 7 months 9 days
Granted (in shares)	50,000	6,000
Granted (in dollars per share)	$ 2.72	$ 2.92
Granted (Year)	5 years	7 years
Exercised (in shares)	(2,000)	(22,000)
Exercised (in dollars per share)	$ 2.70	$ 2.65
Forfeited (in shares)	(7,000)	(7,000)
Forfeited (in dollars per share)	$ 2.58	$ 2.51
Outstanding, intrinsic value		$ 17,000		$ 2,000
Exercisable (in shares)	50,000	383,000
Exercisable, grant date weighted-average exercise price (in dollars per share)	$ 2.74	$ 2.80
Exercisable, weighted average remaining contractual life (Year)		9 months 7 days
Outstanding (in shares)	108,000	394,000	67,000	417,000
Outstanding, grant date weighted-average exercise price (in dollars per share)	$ 2.73	$ 2.80	$ 2.72	$ 2.79
Minimum [Member]
Outstanding, weighted average remaining contractual life (Year)	4 years 10 months 6 days
Exercisable, weighted average remaining contractual life (Year)	2 years 8 months 26 days
Maximum [Member]
Outstanding, intrinsic value	$ 9,000