Note 7 - Loans and the Allowance for Loan Losses - Loan Receivables on Nonaccrual Status (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans receivable on nonaccrual status	$ 11,691	$ 12,535
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member]
Loans receivable on nonaccrual status	32	92
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member]
Loans receivable on nonaccrual status	112
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Loans receivable on nonaccrual status	6,031	5,935
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member]
Loans receivable on nonaccrual status	2,728	2,429
Residential Portfolio Segment [Member] | Multi-family Residential [Member]
Loans receivable on nonaccrual status
Commercial Portfolio Segment [Member]
Loans receivable on nonaccrual status	2,663	3,638
Consumer Portfolio Segment [Member]
Loans receivable on nonaccrual status	$ 125	$ 441