Note 18 - Earnings Per Share - Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income	$ 11,550	$ 8,266	$ 8,238	$ 7,872	$ 9,564	$ 9,156	$ 10,451	$ 9,631	$ 35,926	$ 38,802	$ 36,340
Weighted average common shares outstanding, basic (in shares)	17,717,356	17,710,283	17,701,853	17,998,994	15,611,093	15,603,992	15,712,204	15,839,424	17,781,748	15,690,812	16,587,504
Total dilutive effect of potential common shares (in shares)									33,632	65,281	78,881
Weighted average common shares outstanding, diluted (in shares)	17,751,805	17,732,428	17,728,300	18,050,071	15,670,047	15,664,587	15,775,320	15,920,950	17,815,380	15,756,093	16,666,385
Basic earnings per common share (in dollars per share)	$ 0.65	$ 0.47	$ 0.47	$ 0.44	$ 0.61	$ 0.59	$ 0.67	$ 0.61	$ 2.02	$ 2.47	$ 2.19
Diluted earnings per common share (in dollars per share)	$ 0.65	$ 0.47	$ 0.46	$ 0.44	$ 0.61	$ 0.58	$ 0.66	$ 0.60	$ 2.02	$ 2.46	$ 2.18
Antidilutive potential common shares (in shares)									85,066	25,878	2,755
Share-based Payment Arrangement, Option [Member]
Dilutive effect of potential common shares (in shares)									22,495	53,907	62,417
Antidilutive potential common shares (in shares)									58,166	25	19
Restricted Stock [Member]
Dilutive effect of potential common shares (in shares)									11,137	11,374	16,464
Antidilutive potential common shares (in shares)									26,900	25,853	2,736