Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Past Due and Nonaccrual Loans (Details) - USD ($) $ in Thousands		Jun. 30, 2021		Dec. 31, 2020		Jun. 30, 2020
Gross loans		$ 807,206		$ 770,027
Loans past due 90 days or more and still accruing		28	[1]	17	[1]	$ 237
Nonaccruals		3,822	[1],[2]	3,685	[1],[3]	$ 3,830
Consumer Real Estate Portfolio Segment [Member]
Gross loans		196,214		181,782
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Loans past due 90 days or more and still accruing	[1]	0		0
Nonaccruals	[1]	0	[2]	62	[3]
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Loans past due 90 days or more and still accruing	[1]			0
Nonaccruals	[1],[3]			0
Commercial Real Estate Portfolio Segment [Member]
Gross loans		404,636		393,115
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member]
Loans past due 90 days or more and still accruing	[1]	0		0
Nonaccruals	[1]	2,792	[2]	2,941	[3]
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans past due 90 days or more and still accruing	[1]	0		0
Nonaccruals	[1]	654	[2]	654	[3]
Commercial Non Real Estate Segment [Member]
Gross loans		73,522		78,771
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Loans past due 90 days or more and still accruing	[1]	18		0
Nonaccruals	[1]	376	[2]	28	[3]
Consumer Non Real Estate Portfolio Segment [Member]
Gross loans		31,895		33,110
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due 90 days or more and still accruing	[1]	0		1
Nonaccruals	[1]	0	[2]	0	[3]
Consumer Non Real Estate Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due 90 days or more and still accruing	[1]	10		13
Nonaccruals	[1]	0	[2]	0	[3]
Consumer Non Real Estate Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans past due 90 days or more and still accruing	[1]			3
Nonaccruals	[1],[3]			0
Financing Receivables 30 to 89 Days Past Due [Member]
Gross loans	[1]	1,099		1,497
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Gross loans	[1]	463		365
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Gross loans	[1]			106
Financing Receivables 30 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member]
Gross loans	[1]	205		15
Financing Receivables 30 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Gross loans	[1]	0		0
Financing Receivables 30 to 89 Days Past Due [Member] | Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Gross loans	[1]	186		730
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Gross loans	[1]	92		144
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Other Consumer Loans [Member]
Gross loans	[1]	153		130
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Credit Card Receivable [Member]
Gross loans	[1]			7
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Gross loans	[1]	1,136		1,331
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Gross loans	[1]	0		62
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Gross loans	[1]			0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member]
Gross loans	[1]	454		571
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Gross loans	[1]	654		654
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Gross loans	[1]	18		27
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Gross loans	[1]	0		1
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Other Consumer Loans [Member]
Gross loans	[1]	$ 10		13
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Credit Card Receivable [Member]
Gross loans	[1]			$ 3

[1] Only classes with past-due or nonaccrual loans are shown.

[2] Includes current and past due loans in nonaccrual status. Includes impaired loans in nonaccrual status.

[3] Includes current and past due loans in nonaccrual status. Includes impaired loans in nonaccrual status.