Note 7 - Loans and the Allowance for Loan Losses - Loan Receivables on Nonaccrual Status (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Loans receivable on nonaccrual status	$ 8,977	$ 11,691
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member]
Loans receivable on nonaccrual status	397	32
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member]
Loans receivable on nonaccrual status	339	112
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Loans receivable on nonaccrual status	3,655	6,031
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member]
Loans receivable on nonaccrual status	2,349	2,728
Residential Portfolio Segment [Member] | Multi-family Residential [Member]
Loans receivable on nonaccrual status
Commercial Portfolio Segment [Member]
Loans receivable on nonaccrual status	1,825	2,663
Consumer Portfolio Segment [Member]
Loans receivable on nonaccrual status	$ 412	$ 125