Note 5 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Impaired Loans and Associated Reserves (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Principal balance		$ 7,211	$ 12,319
Total recorded investment	[1]	6,820	11,924
Recorded investment for which there is no related allowance	[1]	5,667	10,444
Recorded investment for which there is a related allowance	[1]	1,153	1,480
Related allowance		139	177
Impaired loans with no valuation allowance	[1]	5,667	10,444
Impaired loans with a valuation allowance	[1]	1,153	1,480
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Principal balance	[2]	728	807
Total recorded investment	[1],[2]	719	768
Recorded investment for which there is no related allowance	[1],[2]	719	590
Recorded investment for which there is a related allowance	[1],[2]		178
Related allowance	[2]		10
Impaired loans with no valuation allowance	[1],[2]	719	590
Impaired loans with a valuation allowance	[1],[2]		178
Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member]
Principal balance	[2]	144	174
Total recorded investment	[1],[2]	143	174
Recorded investment for which there is no related allowance	[1],[2]	0	0
Recorded investment for which there is a related allowance	[1],[2]	143	174
Related allowance	[2]	4	6
Impaired loans with no valuation allowance	[1],[2]	0	0
Impaired loans with a valuation allowance	[1],[2]	143	174
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Principal balance	[2]	593	347
Total recorded investment	[1],[2]	590	325
Recorded investment for which there is no related allowance	[1],[2]	590	325
Recorded investment for which there is a related allowance	[1],[2]	0
Related allowance	[2]	0
Impaired loans with no valuation allowance	[1],[2]	590	325
Impaired loans with a valuation allowance	[1],[2]	0
Real Estate Construction Portfolio Segment[Member] | Construction Loans [Member]
Principal balance	[2]		2,882
Total recorded investment	[1],[2]		2,882
Recorded investment for which there is no related allowance	[1],[2]		2,882
Recorded investment for which there is a related allowance	[1],[2]
Related allowance	[2]		0
Impaired loans with no valuation allowance	[1],[2]		2,882
Impaired loans with a valuation allowance	[1],[2]
Commercial Real Estate Portfolio Segment [Member] | Multifamily Real Estate [Member]
Principal balance	[2]	485	303
Total recorded investment	[1],[2]	483	303
Recorded investment for which there is no related allowance	[1],[2]	483	303
Recorded investment for which there is a related allowance	[1],[2]		0
Related allowance	[2]	0	0
Impaired loans with no valuation allowance	[1],[2]	483	303
Impaired loans with a valuation allowance	[1],[2]		0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member]
Principal balance	[2]	1,363	3,619
Total recorded investment	[1],[2]	1,363	3,611
Recorded investment for which there is no related allowance	[1],[2]	1,363	3,611
Recorded investment for which there is a related allowance	[1],[2]	0
Related allowance	[2]	0
Impaired loans with no valuation allowance	[1],[2]	1,363	3,611
Impaired loans with a valuation allowance	[1],[2]	0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Principal balance	[2]	2,867	2,921
Total recorded investment	[1],[2]	2,494	2,602
Recorded investment for which there is no related allowance	[1],[2]	2,494	2,602
Recorded investment for which there is a related allowance	[1],[2]	0	0
Related allowance	[2]	0	0
Impaired loans with no valuation allowance	[1],[2]	2,494	2,602
Impaired loans with a valuation allowance	[1],[2]	0	0
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Principal balance	[2]	1,018	1,236
Total recorded investment	[1],[2]	1,015	1,229
Recorded investment for which there is no related allowance	[1],[2]	5	126
Recorded investment for which there is a related allowance	[1],[2]	1,010	1,103
Related allowance	[2]	135	160
Impaired loans with no valuation allowance	[1],[2]	5	126
Impaired loans with a valuation allowance	[1],[2]	1,010	1,103
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Principal balance	[2]	13	30
Total recorded investment	[1],[2]	13	30
Recorded investment for which there is no related allowance	[1],[2]	13	5
Recorded investment for which there is a related allowance	[1],[2]		25
Related allowance	[2]		1
Impaired loans with no valuation allowance	[1],[2]	13	5
Impaired loans with a valuation allowance	[1],[2]		$ 25

[1] Recorded investment is net of charge-offs and interest paid while a loan is in nonaccrual status.

[2] Only classes with impaired loans are shown.