Note 15 - Stock-based Compensation - Shares Authorized Under Stock Option Plan (Details)	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Number of shares outstanding (in shares) | shares	456,293
Weighted average remaining contractual life (Year)	2 years 10 months 2 days
Weighted average exercise price (in dollars per share)	$ 2.16
Price Range 1 [Member]
Exercise price, lower range (in dollars per share)	1.00
Exercise price, upper range (in dollars per share)	$ 1.50
Number of shares outstanding (in shares) | shares	2,000
Weighted average remaining contractual life (Year)	3 years 10 months 6 days
Weighted average exercise price (in dollars per share)	$ 1.49
Price Range 2 [Member]
Exercise price, lower range (in dollars per share)	1.51
Exercise price, upper range (in dollars per share)	$ 2.00
Number of shares outstanding (in shares) | shares	177,500
Weighted average remaining contractual life (Year)	3 years 3 months 10 days
Weighted average exercise price (in dollars per share)	$ 1.90
Price Range 3 [Member]
Exercise price, lower range (in dollars per share)	2.01
Exercise price, upper range (in dollars per share)	$ 2.50
Number of shares outstanding (in shares) | shares	255,938
Weighted average remaining contractual life (Year)	2 years 4 months 6 days
Weighted average exercise price (in dollars per share)	$ 2.06
Price Range 4 [Member]
Exercise price, lower range (in dollars per share)	2.51
Exercise price, upper range (in dollars per share)	$ 8.60
Number of shares outstanding (in shares) | shares	20,855
Weighted average remaining contractual life (Year)	4 years 11 months 1 day
Weighted average exercise price (in dollars per share)	$ 5.69