Note 14 - Stockholders Equity - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Outstanding, number of shares (in shares)	5,977,179
Outstanding, weighted average exercise price (in dollars per share)	$ 3.72
Outstanding, weighted average remaining contractual term (Year)	7 years 5 months 19 days		7 years 2 months 12 days
Outstanding, aggregate intrinsic value	$ 130		$ 136
Options granted, number of shares (in shares)	2,041,250
Options granted, weighted average exercise price (in dollars per share)	$ 1.38
Options granted, aggregate intrinsic value	$ 102
Options exercised, number of shares (in shares)	(16,464)
Options exercised, weighted average exercise price (in dollars per share)	$ 1.59
Options exercised, aggregate intrinsic value	$ 1	$ 157
Options forfeited/cancelled, number of shares (in shares)	(479,501)
Options forfeited/cancelled, weighted average exercise price (in dollars per share)	$ 4.45
Options forfeited/cancelled, aggregate intrinsic value (in dollars per share)	$ 2
Outstanding, number of shares (in shares)	7,522,464		5,977,179
Outstanding, weighted average exercise price (in dollars per share)	$ 3.05		$ 3.72
Exercisable, number of shares (in shares)	3,020,805
Exercisable, weighted average exercise price (in dollars per share)	$ 4.50
Exercisable, weighted average remaining contractual term (Year)	4 years 7 months 20 days
Exercisable, aggregate intrinsic value	$ 28
Expected to vest, number of shares (in shares)	4,501,659
Expected to vest, weighted average exercise price (in dollars per share)	$ 2.07
Expected to vest, weighted average remaining contractual term (Year)	9 years 4 months 17 days
Expected to vest, aggregate intrinsic value	$ 102