Note 5 - Share-based Compensation - Stock Option Activity Under Equity Incentive Plans and Director Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Exercised, number of options (in shares)	10,014	75,283
Service based Stock Options [Member]
Beginning balance, outstanding, number of options (in shares)	470,321
Beginning balance, outstanding, weighted average exercise price (in dollars per share)	$ 35.38
Granted, number of options (in shares)	11,021	0
Granted, weighted average exercise price (in dollars per share)	$ 17.34
Exercised, number of options (in shares)	10,014
Forfeited, number of options (in shares)	0
Exercised, weighted average exercise price (in dollars per share)	$ 13.17
Expired, number (in shares)	59,965
Outstanding, number (in shares)	411,363
Expired, weighted average exercise price (in dollars per share)	$ 24.7
Outstanding, weighted average exercise price (in dollars per share)	$ 36.99
Outstanding, weighted average contractual term (Year)	6 years 2 months 23 days
Outstanding, aggregate intrinsic value	$ 0
Exercisable, number (in shares)	268,174
Exercisable, weighted average exercise price (in dollars per share)	$ 38.03
Exercisable, weighted average remaining contractual term (Year)	5 years 4 months 2 days
Exercisable, aggregate intrinsic value	$ 0
Performance based Stock Options [Member]
Beginning balance, outstanding, number of options (in shares)	404,833
Beginning balance, outstanding, weighted average exercise price (in dollars per share)	$ 39.54
Granted, number of options (in shares)	0	404,833
Exercised, number of options (in shares)	0
Forfeited, number of options (in shares)	100,000
Forfeited, weighted average exercise price (in dollars per share)	$ 39.54
Outstanding, number (in shares)	304,833
Outstanding, weighted average exercise price (in dollars per share)	$ 39.54
Outstanding, weighted average contractual term (Year)	4 years 9 months 18 days
Outstanding, aggregate intrinsic value	$ 0
Exercisable, number (in shares)	0