Note 4 - Loans - Age Analysis of Past Due Loans and Nonaccrual Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Loans	$ 958,723	$ 782,027	$ 779,443
Financial Asset Originated [Member]
Accruing loans past due	2,223	8,234
Nonaccrual loans	9,572	9,482
Current loans	814,514	745,924
Loans	826,309	763,640
Financial Assets Acquired [Member]
Accruing loans past due	530
Nonaccrual loans	571
Current loans	131,313	18,387
Loans	132,414	18,387
Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due	2,223	8,234
Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due	530
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member]
Loans	76,232	57,410	47,292
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Financial Asset Originated [Member]
Accruing loans past due	165	282
Nonaccrual loans	460	637
Current loans	51,460	49,262
Loans	52,085	50,181
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Financial Assets Acquired [Member]
Accruing loans past due	491
Nonaccrual loans	442
Current loans	23,214	7,229
Loans	24,147	7,229
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due	165	282
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due	491
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member]
Loans	20,741	16,799	21,415
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Financial Asset Originated [Member]
Accruing loans past due	71	117
Nonaccrual loans	1,214	413
Current loans	19,177	15,463
Loans	20,462	15,993
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Nonaccrual loans
Current loans	279	806
Loans	279	806
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due	71	117
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans	450,700	373,534	349,408
Real Estate Portfolio Segment [Member] | Commercial [Member] | Financial Asset Originated [Member]
Accruing loans past due	497	679
Nonaccrual loans	1,567	2,966
Current loans	390,617	363,147
Loans	392,681	366,792
Real Estate Portfolio Segment [Member] | Commercial [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Nonaccrual loans
Current loans	58,019	6,742
Loans	58,019	6,742
Real Estate Portfolio Segment [Member] | Commercial [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due	497	679
Real Estate Portfolio Segment [Member] | Commercial [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Commercial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Commercial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Commercial Construction [Member]
Loans	74,000	47,849	53,570
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Financial Asset Originated [Member]
Accruing loans past due	89	88
Nonaccrual loans	10	463
Current loans	64,181	46,058
Loans	64,280	46,609
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Nonaccrual loans	66
Current loans	9,654	1,240
Loans	9,720	1,240
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due	89	88
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Loans	20,039	12,500	12,897
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Financial Asset Originated [Member]
Accruing loans past due	59
Nonaccrual loans
Current loans	15,021	12,242
Loans	15,080	12,242
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Nonaccrual loans
Current loans	4,959	258
Loans	4,959	258
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due	59
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Residential [Member]
Loans	198,654	187,714	189,153
Real Estate Portfolio Segment [Member] | Residential [Member] | Financial Asset Originated [Member]
Accruing loans past due	1,083	6,882
Nonaccrual loans	3,605	2,734
Current loans	168,165	176,083
Loans	172,853	185,699
Real Estate Portfolio Segment [Member] | Residential [Member] | Financial Assets Acquired [Member]
Accruing loans past due	35
Nonaccrual loans	23
Current loans	25,743	2,015
Loans	25,801	2,015
Real Estate Portfolio Segment [Member] | Residential [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due	1,083	6,882
Real Estate Portfolio Segment [Member] | Residential [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due	35
Real Estate Portfolio Segment [Member] | Residential [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Residential [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Farmland [Member]
Loans	74,341	62,709	70,069
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financial Asset Originated [Member]
Accruing loans past due	150	76
Nonaccrual loans	2,592	2,052
Current loans	68,464	60,546
Loans	71,206	62,674
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Nonaccrual loans	37
Current loans	3,098	35
Loans	3,135	35
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due	150	76
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Consumer and Other Portfolio Segment [Member] | Consumer [Member]
Loans	22,756	18,485	18,623
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Financial Asset Originated [Member]
Accruing loans past due	109	110
Nonaccrual loans	124	213
Current loans	17,838	18,100
Loans	18,071	18,423
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Financial Assets Acquired [Member]
Accruing loans past due	4
Nonaccrual loans	3
Current loans	4,678	62
Loans	4,685	62
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due	109	110
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due	4
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Consumer and Other Portfolio Segment [Member] | Other [Member]
Loans	21,260	5,027	$ 17,016
Consumer and Other Portfolio Segment [Member] | Other [Member] | Financial Asset Originated [Member]
Accruing loans past due
Nonaccrual loans		4
Current loans	19,591	5,023
Loans	19,591	5,027
Consumer and Other Portfolio Segment [Member] | Other [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Nonaccrual loans
Current loans	1,669
Loans	1,669
Consumer and Other Portfolio Segment [Member] | Other [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Consumer and Other Portfolio Segment [Member] | Other [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due
Consumer and Other Portfolio Segment [Member] | Other [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Asset Originated [Member]
Accruing loans past due
Consumer and Other Portfolio Segment [Member] | Other [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Financial Assets Acquired [Member]
Accruing loans past due