Note 13 - Earnings Per Share - Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net income	$ 8,238	$ 10,451	$ 16,110	$ 20,082
Weighted average common shares outstanding, basic (in shares)	17,701,853	15,712,204	17,850,423	15,775,462
Total dilutive effect of potential common shares (in shares)	26,447	63,116	37,902	72,036
Weighted average common shares outstanding, diluted (in shares)	17,728,300	15,775,320	17,888,325	15,847,498
Basic earnings per common share (in dollars per share)	$ 0.47	$ 0.67	$ 0.90	$ 1.27
Diluted earnings per common share (in dollars per share)	$ 0.46	$ 0.66	$ 0.90	$ 1.27
Antidilutive potential common shares (in shares)	95,036	0	98,967	0
Share-based Payment Arrangement, Option [Member]
Dilutive effect of potential common shares (in shares)	20,661	56,818	27,017	57,795
Antidilutive potential common shares (in shares)	60,375	0	66,808	0
Restricted Stock [Member]
Dilutive effect of potential common shares (in shares)	5,786	6,298	10,885	14,241
Antidilutive potential common shares (in shares)	34,661	0	32,159	0