Note 20 - Quarterly Financial Data (Unaudited) - Summary of Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income	$ 26,892		$ 26,208		$ 26,245		$ 25,519		$ 25,293		$ 23,558		$ 22,324		$ 20,899		$ 104,864	$ 92,074	$ 70,849
Interest expense	6,978		6,826		6,874		6,379		5,313		4,412		3,662		2,783		27,057	16,170	8,784
Interest income	19,914		19,382		19,371		19,140		19,980		19,146		18,662		18,116		77,807	75,904	62,065
Provision for loan losses	1,155		450				300		600		500		800		400		1,905	2,300	900
Total non-interest income	5,213		6,554		7,026		4,945		4,888		5,131		5,768		4,535		23,738	20,322	20,097
Non-interest expense	27,488		27,824		25,911		23,267		22,057		20,833		20,729		20,102		104,490	83,721	75,276
Provision (benefit) for income taxes	(1,031)		(516)		105		92		54		622		530		372		(1,350)	1,578	(2,919)
Net (loss) income	$ (2,485)		$ (1,822)		$ 381		$ 426		$ 2,157		$ 2,322		$ 2,371		$ 1,777		$ (3,500)	$ 8,627	$ 8,905
Basic (in dollars per share)	$ (0.04)	[1]	$ (0.03)	[1]	$ 0.01	[1]	$ 0.01	[1]	$ 0.04	[1]	$ 0.04	[1]	$ 0.04	[1]	$ 0.03	[1]	$ (0.06)	$ 0.15	$ 0.16
Diluted (in dollars per share)	$ (0.04)	[1]	$ (0.03)	[1]	$ 0.01	[1]	$ 0.01	[1]	$ 0.04	[1]	$ 0.04	[1]	$ 0.04	[1]	$ 0.03	[1]	$ (0.06)	$ 0.15	$ 0.15

[1] Quarterly net income per share does not add to full year net income per share due to rounding.