Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Past Due and Nonaccrual Loans (Details) - USD ($) $ in Thousands		Sep. 30, 2019		Dec. 31, 2018		Sep. 30, 2018
Loans past due 90 days or more and still accruing		$ 212	[1]	$ 35	[1]	$ 63
Nonaccruals		4,076	[1],[2]	3,420	[1],[2]	$ 3,076
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Loans past due 90 days or more and still accruing	[1]	36
Nonaccruals	[1],[2]	681		278
Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member]
Loans past due 90 days or more and still accruing	[1]	132
Nonaccruals	[1],[2]	0		0
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Loans past due 90 days or more and still accruing	[1]	0		0
Nonaccruals	[1],[2]	264		451
Commercial Real Estate Portfolio Segment [Member] | Multifamily Real Estate [Member]
Loans past due 90 days or more and still accruing	[1]	0		0
Nonaccruals	[1],[2]			192
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]	531
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],[2]	2,451		2,494
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Loans past due 90 days or more and still accruing	[1]
Nonaccruals	[1],[2]	144
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans past due 90 days or more and still accruing	[1]			2
Nonaccruals	[1],[2]			5
Consumer Non Real Estate Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans past due 90 days or more and still accruing	[1]	1
Nonaccruals	[1],[2]	0		0
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due 90 days or more and still accruing	[1]	40		29
Nonaccruals	[1],[2]
Consumer Non Real Estate Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due 90 days or more and still accruing	[1]	3		4
Nonaccruals	[1],[2]	5		0
Financing Receivables 30 to 89 Days Past Due [Member]
Loans past due and accruing	[1]	1,735		1,635
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Loans past due and accruing	[1]	888		647
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member]
Loans past due and accruing	[1]	22		11
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Loans past due and accruing	[1]
Financing Receivables 30 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Multifamily Real Estate [Member]
Loans past due and accruing	[1]	94		291
Financing Receivables 30 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member]
Loans past due and accruing	[1]	243		325
Financing Receivables 30 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans past due and accruing	[1]	0		0
Financing Receivables 30 to 89 Days Past Due [Member] | Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Loans past due and accruing	[1]	211
Financing Receivables 30 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans past due and accruing	[1]			10
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans past due and accruing	[1]	1		5
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due and accruing	[1]	185		296
Financing Receivables 30 to 89 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due and accruing	[1]	91		50
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due and accruing	[1]	1,594		346
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Loans past due and accruing	[1]	717		119
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member]
Loans past due and accruing	[1]	132
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Loans past due and accruing	[1]	264
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Multifamily Real Estate [Member]
Loans past due and accruing	[1]			192
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member]
Loans past due and accruing	[1]	293
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Loans past due and accruing	[1]
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Loans past due and accruing	[1]	144
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans past due and accruing	[1]			2
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans past due and accruing	[1]	1
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due and accruing	[1]	40		29
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Non Real Estate Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due and accruing	[1]	$ 3		$ 4

[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.