Note 8 - Share-based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Stock options outstanding, beginning of period (in shares)	1,649,686
Balance, weighted average exercise price, beginning of period (in dollars per share)	$ 5.00
Stock options outstanding, weighted average remaining contractual term (Year)	7 years 8 months 12 days	7 years 7 months 6 days
Stock options outstanding, aggregate intrinsic value	$ 248	$ 0
Stock options granted (in shares)	603,953
Stock options granted, weighted average exercise price (in dollars per share)	$ 1.54
Stock options exercised (in shares)	0
Stock options forfeited (in shares)	(101,796)
Stock options forfeited, weighted average exercise price (in dollars per share)	$ 3.77
Stock options expired (in shares)	(3,111)
Stock options expired, weighted average exercise price (in dollars per share)	$ 9.55
Balance, March 31, 2022 (in shares)	2,148,732	1,649,686
Balance, weighted average exercise price, beginning of period (in dollars per share)	$ 4.08	$ 5.00
Exercisable, March 31, 2022 (in shares)	1,052,136
Options exercisable, weighted average exercise price (in dollars per share)	$ 5.70
Options exercisable, weighted average remaining contractual term (Year)	6 years 6 months