Note 8 - Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	$ 10,822	$ 6,960
Loans current	810,307	813,459
Loans and leases receivable	821,129	820,419
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	5,469	1,994
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	1,311	804
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	4,042	4,162
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	4,473	2,064
Loans current	159,598	165,967
Loans and leases receivable	164,071	168,031
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	2,630	0
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	100	58
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	1,743	2,006
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
Loans current	47,634	56,209
Loans and leases receivable	47,634	56,209
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
Commercial Portfolio Segment [Member] | Secured by Commercial Real Estate [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	2,973	1,527
Loans current	348,577	334,523
Loans and leases receivable	351,550	336,050
Commercial Portfolio Segment [Member] | Secured by Commercial Real Estate [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	332	0
Commercial Portfolio Segment [Member] | Secured by Commercial Real Estate [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	1,121	0
Commercial Portfolio Segment [Member] | Secured by Commercial Real Estate [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	1,520	1,527
Commercial Portfolio Segment [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	343	429
Loans current	70,309	72,014
Loans and leases receivable	70,652	72,443
Commercial Portfolio Segment [Member] | Secured by Residential Real Estate [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	252	208
Commercial Portfolio Segment [Member] | Secured by Residential Real Estate [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	12	79
Commercial Portfolio Segment [Member] | Secured by Residential Real Estate [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	79	142
State and Political Subdivisions Portfolio Segment [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
Loans current	38,248	38,376
Loans and leases receivable	38,248	38,376
State and Political Subdivisions Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
State and Political Subdivisions Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
State and Political Subdivisions Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
Retail Portfolio Segment [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	239	100
Loans current	5,993	6,430
Loans and leases receivable	6,232	6,530
Retail Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	121	29
Retail Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	31	71
Retail Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	87	0
Retail Portfolio Segment [Member] | Family Residential Mortgages [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	2,566	2,491
Loans current	67,718	66,978
Loans and leases receivable	70,284	69,469
Retail Portfolio Segment [Member] | Family Residential Mortgages [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	2,108	1,486
Retail Portfolio Segment [Member] | Family Residential Mortgages [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	573
Retail Portfolio Segment [Member] | Family Residential Mortgages [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	458	432
Retail Portfolio Segment [Member] | Home Equity Loans and Lines [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	228	349
Loans current	72,230	72,962
Loans and leases receivable	72,458	73,311
Retail Portfolio Segment [Member] | Home Equity Loans and Lines [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	26	271
Retail Portfolio Segment [Member] | Home Equity Loans and Lines [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	47	23
Retail Portfolio Segment [Member] | Home Equity Loans and Lines [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	$ 155	$ 55