Note 8 - Stockholders' Equity - Summary of Warrant Activity (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Outstanding (in shares)	1,192,085
Outstanding, weighted average exercise price (in dollars per share)	$ 3.57
Outstanding, weighted average remaining contractual life (Year)	3 years	3 years 9 months
Issued (in shares)	0
Issued, weighted average exercise price (in dollars per share)	$ 0
Expired (in shares)	0
Expired, weighted average exercise price (in dollars per share)	$ 0
Outstanding (in shares)	1,192,085	1,192,085
Outstanding, weighted average exercise price (in dollars per share)	$ 3.57	$ 3.57
Exercisable (in shares)	1,192,085
Exercisable, weighted average exercise price (in dollars per share)	$ 3.57
Exercisable, weighted average remaining contractual life (Year)	3 years