Note 3 - Loans - Recorded Investment in Nonaccrual and Loans Past Due 90 Days and Still on Accrual by Class of Loan (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Nonaccrual	$ 1,528	$ 1,991
Loans Past Due 90 Days and Over Still Accruing	0	0
Commercial Portfolio Segment [Member]
Nonaccrual	50	53
Loans Past Due 90 Days and Over Still Accruing	0	0
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Nonaccrual	0	0
Loans Past Due 90 Days and Over Still Accruing	0	0
Commercial Real Estate Portfolio Segment [Member] | Farmland Loans [Member]
Nonaccrual	431	249
Loans Past Due 90 Days and Over Still Accruing	0	0
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Nonaccrual	90	61
Loans Past Due 90 Days and Over Still Accruing	0	0
Residential Portfolio Segment [Member] | Multifamily Loans [Member]
Nonaccrual	0	0
Loans Past Due 90 Days and Over Still Accruing	0	0
Residential Portfolio Segment [Member] | One- to Four-family Residential Properties [Member]
Nonaccrual	817	1,628
Loans Past Due 90 Days and Over Still Accruing	0	0
Consumer Portfolio Segment [Member]
Nonaccrual	98	0
Loans Past Due 90 Days and Over Still Accruing	0	0
Agriculture Portfolio Segment [Member]
Nonaccrual	42	0
Loans Past Due 90 Days and Over Still Accruing	0	0
Other Portfolio Segment [Member]
Nonaccrual	0	0
Loans Past Due 90 Days and Over Still Accruing	$ 0	$ 0