NOTE 7 - EARNINGS PER SHARE - Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share
Net income	$ 15,095	$ 13,504	$ 12,918	$ 8,809	$ 10,445	$ 10,550	$ 41,517	$ 29,804
Basic earnings per common share (in dollars per share)	$ 0.96			$ 0.56			$ 2.64	$ 2.06
Diluted earnings per common share (in dollars per share)	$ 0.94			$ 0.55			$ 2.60	$ 2.02
Weighted average common shares outstanding (in shares)	15,739,430			15,625,123			15,715,788	14,477,783
Weighted average common shares issuable upon exercise of stock options and under the employee stock purchase plan** (in shares)	237,312			297,201			230,232	308,994
Weighted average common and common equivalent shares outstanding (in shares)	15,976,742			15,922,324			15,946,020	14,786,777