Note 4 - Loans - Performing and Non-performing Loan Delinquency Status (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Loans past due	$ 833,154	$ 826,356
Performing Financial Instruments [Member]
Loans past due	824,578	817,272
Nonperforming Financial Instruments [Member]
Loans past due	8,576	9,084
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	170,342	169,149
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	1,422	1,574
Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	271,240	272,742
Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	43,929	47,484
Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due	160,532	146,421
Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due	1,122	1,202
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	128,582	137,568
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	610	671
State and Political Subdivisions [Member] | Performing Financial Instruments [Member]
Loans past due	49,953	43,908
State and Political Subdivisions [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	5,422	5,637
Financial Asset, 1 to 29 Days Past Due [Member]
Loans past due	825,514	818,841
Financial Asset, 1 to 29 Days Past Due [Member] | Performing Financial Instruments [Member]
Loans past due	821,377	814,312
Financial Asset, 1 to 29 Days Past Due [Member] | Nonperforming Financial Instruments [Member]
Loans past due	4,137	4,529
Financial Asset, 1 to 29 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	169,878	168,754
Financial Asset, 1 to 29 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	622	873
Financial Asset, 1 to 29 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	271,197	272,561
Financial Asset, 1 to 29 Days Past Due [Member] | Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	43,929	47,484
Financial Asset, 1 to 29 Days Past Due [Member] | Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Financial Asset, 1 to 29 Days Past Due [Member] | Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due	160,057	146,221
Financial Asset, 1 to 29 Days Past Due [Member] | Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due	868	943
Financial Asset, 1 to 29 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	126,363	135,384
Financial Asset, 1 to 29 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	213	193
Financial Asset, 1 to 29 Days Past Due [Member] | State and Political Subdivisions [Member] | Performing Financial Instruments [Member]
Loans past due	49,953	43,908
Financial Asset, 1 to 29 Days Past Due [Member] | State and Political Subdivisions [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Financial Asset, 1 to 29 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	2,434	2,520
Financial Asset, 30 to 59 Days Past Due [Member]
Loans past due	2,716	3,107
Financial Asset, 30 to 59 Days Past Due [Member] | Performing Financial Instruments [Member]
Loans past due	2,475	2,104
Financial Asset, 30 to 59 Days Past Due [Member] | Nonperforming Financial Instruments [Member]
Loans past due	241	1,003
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	464	134
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	223	17
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	43	75
Financial Asset, 30 to 59 Days Past Due [Member] | Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due	249	200
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	1,719	1,695
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	18	93
Financial Asset, 30 to 59 Days Past Due [Member] | State and Political Subdivisions [Member] | Performing Financial Instruments [Member]
Loans past due	0
Financial Asset, 30 to 59 Days Past Due [Member] | State and Political Subdivisions [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due		893
Financial Asset, 60 to 89 Days Past Due [Member]
Loans past due	910	1,670
Financial Asset, 60 to 89 Days Past Due [Member] | Performing Financial Instruments [Member]
Loans past due	726	856
Financial Asset, 60 to 89 Days Past Due [Member] | Nonperforming Financial Instruments [Member]
Loans past due	184	814
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due		261
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	14	228
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due		106
Financial Asset, 60 to 89 Days Past Due [Member] | Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due	226
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due		114
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	500	489
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	170	38
Financial Asset, 60 to 89 Days Past Due [Member] | State and Political Subdivisions [Member] | Performing Financial Instruments [Member]
Loans past due	0
Financial Asset, 60 to 89 Days Past Due [Member] | State and Political Subdivisions [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due		434
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due	4,014	2,738
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Performing Financial Instruments [Member]
Loans past due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Nonperforming Financial Instruments [Member]
Loans past due	4,014	2,738
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	563	456
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due	254	145
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	209	347
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | State and Political Subdivisions [Member] | Performing Financial Instruments [Member]
Loans past due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | State and Political Subdivisions [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	$ 2,988	$ 1,790