Note 5 - Loans - Performing and Non-performing Loan Delinquency Status (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Loans past due	$ 826,356	$ 835,207
Performing Financial Instruments [Member]
Loans past due	817,272	830,511
Nonperforming Financial Instruments [Member]
Loans past due	9,084	4,696
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	169,149	164,145
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	1,574	688
Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	272,742	259,904
Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	47,484	20,813
Construction, Land Acquisition and Development [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0	0
Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due	146,421	150,215
Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due	1,202	747
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	137,568	176,397
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	671	387
State and Political Subdivisions [Member] | Performing Financial Instruments [Member]
Loans past due	43,908	59,037
State and Political Subdivisions [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0	0
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	5,637	2,874
Financial Asset, 1 to 29 Days Past Due [Member]
Loans past due	818,841	829,714
Financial Asset, 1 to 29 Days Past Due [Member] | Performing Financial Instruments [Member]
Loans past due	814,312	827,442
Financial Asset, 1 to 29 Days Past Due [Member] | Nonperforming Financial Instruments [Member]
Loans past due	4,529	2,272
Financial Asset, 1 to 29 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	168,754	163,690
Financial Asset, 1 to 29 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	873	443
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	272,561	259,904
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	47,484	20,813
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	0
Financial Asset, 1 to 29 Days Past Due [Member] | Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due	146,221	150,108
Financial Asset, 1 to 29 Days Past Due [Member] | Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due	943	677
Financial Asset, 1 to 29 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	135,384	173,890
Financial Asset, 1 to 29 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	193	91
Financial Asset, 1 to 29 Days Past Due [Member] | State and Political Subdivisions [Member] | Performing Financial Instruments [Member]
Loans past due	43,908	59,037
Financial Asset, 1 to 29 Days Past Due [Member] | State and Political Subdivisions [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0	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	2,520	1,061
Financial Asset, 30 to 59 Days Past Due [Member]
Loans past due	3,107	2,738
Financial Asset, 30 to 59 Days Past Due [Member] | Performing Financial Instruments [Member]
Loans past due	2,104	2,627
Financial Asset, 30 to 59 Days Past Due [Member] | Nonperforming Financial Instruments [Member]
Loans past due	1,003	111
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans past due	134	319
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	17	0
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	75	0
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	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	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due	200	87
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0	50
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	1,695	2,221
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	93	61
Financial Asset, 30 to 59 Days Past Due [Member] | State and Political Subdivisions [Member] | Performing Financial Instruments [Member]
Loans past due	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | State and Political Subdivisions [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0	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	0
Financial Asset, 60 to 89 Days Past Due [Member]
Loans past due	1,670	652
Financial Asset, 60 to 89 Days Past Due [Member] | Performing Financial Instruments [Member]
Loans past due	856	442
Financial Asset, 60 to 89 Days Past Due [Member] | Nonperforming Financial Instruments [Member]
Loans past due	814	210
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	136
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans past due	228	136
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	0
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	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	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due		20
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due	114	0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	489	286
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	38	74
Financial Asset, 60 to 89 Days Past Due [Member] | State and Political Subdivisions [Member] | Performing Financial Instruments [Member]
Loans past due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | State and Political Subdivisions [Member] | Nonperforming Financial Instruments [Member]
Loans past due	0	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	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due	2,738	2,103
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Performing Financial Instruments [Member]
Loans past due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Nonperforming Financial Instruments [Member]
Loans past due	2,738	2,103
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	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	456	109
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	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	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	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial and Industrial [Member] | Performing Financial Instruments [Member]
Loans past due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial and Industrial [Member] | Nonperforming Financial Instruments [Member]
Loans past due	145	20
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans past due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans past due	347	161
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	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	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	$ 1,790	$ 1,813