Note 2 - Mergers and Acquisitions - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Net interest income after loan loss provision		$ 36,158	$ 28,761
Noninterest income		23,841	12,122
Noninterest expense		46,031	34,987
Income before income taxes		13,968	5,896
Income tax expense		3,096	914
Net income		$ 10,872	$ 4,982
Basic earnings per share (in dollars per share)		$ 1.69	$ 0.92
Diluted earnings per share (in dollars per share)		$ 1.69	$ 0.91
Weighted average shares outstanding, basic (in shares)		6,419,654	5,426,605
Weighted average shares outstanding, diluted (in shares)		6,437,604	5,490,347
Big Muddy Bancorp Acquisition [Member] | Pro Forma [Member]
Net interest income after loan loss provision	[1]		$ 33,462
Noninterest income	[1]		12,986
Noninterest expense	[1]		39,422
Income before income taxes			7,026
Income tax expense			1,405
Net income	[1]		$ 5,621
Basic earnings per share (in dollars per share)	[1]		$ 1.04
Diluted earnings per share (in dollars per share)	[1]		$ 1.02
Weighted average shares outstanding, basic (in shares)			5,426,605
Weighted average shares outstanding, diluted (in shares)			5,490,347

[1] Significant assumptions utilized include the acquisition cost noted above and a 20.00% effective tax rate.