Note 6 - EARNINGS PER SHARE - Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
EARNINGS PER SHARE
Net Income (Loss)	$ 28,425	$ 27,157	$ 15,242	$ 23,624	$ 55,582	$ 38,866
Basic EPS	$ 1.70		$ 0.88		$ 3.32	$ 2.36
Diluted EPS	$ 1.69		$ 0.87		$ 3.29	$ 2.33
Weighted average common shares outstanding	16,701,950		17,345,324		16,739,120	16,485,218
Weighted average common shares issuable upon exercise of stock options and under the employee stock purchase plan (in shares)	97,577		203,783		131,710	215,464
Weighted average common and common equivalent shares outstanding	16,799,527		17,549,107		16,870,830	16,700,682