Note 8 - Past Due Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	$ 5,904	$ 6,960
Loans current	884,209	813,459
Loans and leases receivable	890,113	820,419
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	3,572	1,994
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	309	804
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	2,023	4,162
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	4,036	2,064
Loans current	223,412	165,967
Loans and leases receivable	227,448	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	2,428	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	0	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	1,608	2,006
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
Loans current	50,187	56,209
Loans and leases receivable	50,187	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	383	1,527
Loans current	350,629	334,523
Loans and leases receivable	351,012	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	344	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	0	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	39	1,527
Commercial Portfolio Segment [Member] | Secured by Residential Real Estate [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	253	429
Loans current	80,025	72,014
Loans and leases receivable	80,278	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	67	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	0	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	186	142
State and Political Subdivisions Portfolio Segment [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	0	0
Loans current	34,489	38,376
Loans and leases receivable	34,489	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	170	100
Loans current	5,320	6,430
Loans and leases receivable	5,490	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	124	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	4	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	42	0
Retail Portfolio Segment [Member] | Family Residential Mortgages [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	755	2,491
Loans current	75,265	66,978
Loans and leases receivable	76,020	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	310	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	305	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	140	432
Retail Portfolio Segment [Member] | Home Equity Loans and Lines [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due	307	349
Loans current	64,882	72,962
Loans and leases receivable	65,189	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	299	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	0	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	$ 8	$ 55