Note 9 - Deposits - Interest Expense on Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
NOW, Interest expense	$ 18	$ 15	$ 7
NOW, Weighted Avg. Effective Interest Rate	0.07%	0.06%	0.03%
Savings, Interest expense	$ 429	$ 995	$ 1,160
Savings, Weighted Avg. Effective Interest Rate	0.63%	0.85%	0.81%
Money market, Interest expense	$ 2,048	$ 549	$ 5
Money market, Weighted Avg. Effective Interest Rate	2.00%	1.34%	0.04%
Certificates of deposit, less than $250,000, Interest expense	$ 4,986	$ 3,048	$ 1,875
Certificates of deposit, less than $250,000, Weighted Avg. Effective Interest Rate	2.38%	1.57%	1.05%
Certificates of deposit, $250,000 or greater, Interest expense	$ 1,546	$ 1,226	$ 912
Certificates of deposit, $250,000 or greater, Weighted Avg. Effective Interest Rate	2.01%	1.68%	1.46%
Brokered deposits, Interest expense	$ 4,958	$ 3,191	$ 989
Brokered deposits, Weighted Avg. Effective Interest Rate	2.47%	1.91%	1.24%
Interest Expense on Deposits, Total, Interest expense	$ 13,985	$ 9,024	$ 4,948
Interest Expense on Deposits, Total, Weighted Avg. Effective Interest Rate	2.05%	1.46%	0.99%