Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Past Due and Nonaccrual Loans (Details) - USD ($) $ in Thousands		Sep. 30, 2020		Dec. 31, 2019		Sep. 30, 2019
Loans past due 90 days or more and still accruing		$ 236	[1]	$ 231	[1]	$ 212
Nonaccruals		3,602	[1],[2]	3,375	[1],[2]	$ 4,076
Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	1,295		1,070
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]	1,451		940
Real Estate Construction Portfolio Segment[Member] | Construction, Other [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]			19
Consumer Real Estate Portfolio Segment [Member] | Equity Lines [Member]
Loans past due 90 days or more and still accruing	[1]	19
Consumer Real Estate Portfolio Segment [Member] | Equity Lines [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	30
Consumer Real Estate Portfolio Segment [Member] | Equity Lines [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]	19
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Loans past due 90 days or more and still accruing	[1]	39		188
Nonaccruals	[1],[2]	82		22
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	526		499
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]	121		210
Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]			83
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Nonaccruals	[1],[2]			264
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	107
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]			264
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member]
Nonaccruals	[1],[2]	479		514
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	147
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]	582		287
Commercial Real Estate Portfolio Segment [Member] | Multifamily Real Estate [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]			94
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Nonaccruals	[1],[2]	3,041		2,435
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]	654
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Loans past due 90 days or more and still accruing	[1]	61		17
Nonaccruals	[1],[2]			136
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	127		45
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]			153
Consumer Non Real Estate Portfolio Segment [Member] | Credit Card Receivable [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	5		4
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due 90 days or more and still accruing	[1]			14
Nonaccruals	[1],[2]			4
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	170		256
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]			14
Consumer Non Real Estate Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due 90 days or more and still accruing	[1]	12		12
Consumer Non Real Estate Portfolio Segment [Member] | Other Consumer Loans [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	165		70
Consumer Non Real Estate Portfolio Segment [Member] | Other Consumer Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]	$ 12		$ 12

[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.