Note 5 - Credit Quality - Loans Modified as Troubled Debt Restructurings by Loan Class and Accrual Status (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Nonaccrual	[1]	$ 2,342	$ 2,581
Accrual		6,575	6,427
TDRs		8,917	9,008
Allowance for loan losses related to TDRs		353	568
Commercial Portfolio Segment [Member] | Single Family Non-owner Occupied [Member]
Nonaccrual	[1]	552	640
Accrual		595	309
TDRs		1,147	949
Commercial Portfolio Segment [Member] | Non-farm, Non-residential [Member]
Nonaccrual	[1]
Accrual		307	314
TDRs		307	314
Consumer Real Estate Portfolio Segment [Member] | Home Equity Lines [Member]
Nonaccrual	[1]
Accrual		115	127
TDRs		115	127
Consumer Real Estate Portfolio Segment [Member] | Single Family Owner Occupied [Member]
Nonaccrual	[1]	1,790	1,941
Accrual		5,305	5,417
TDRs		7,095	7,358
Consumer Real Estate Portfolio Segment [Member] | Owner Occupied Construction [Member]
Nonaccrual	[1]
Accrual		221	225
TDRs		221	225
Consumer and Other Portfolio Segment [Member]
TDRs			35
Consumer and Other Portfolio Segment [Member] | Consumer Loans [Member]
Nonaccrual	[1]
Accrual		32	$ 35
TDRs		$ 32

[1] Nonaccrual TDRs are included in total nonaccrual loans disclosed in the nonaccrual table above.