Note 4 - Loans - Impaired Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Recorded investment with no related allowance recorded	$ 6,363	$ 7,626
Unpaid principal balance with no related allowance recorded	8,071	10,332
Recorded investment with related allowance recorded	5,099	5,521
Unpaid principal balance with related allowance recorded	5,207	5,663
Related allowance	1,089	1,169
Recorded investment	11,462	13,147
Unpaid principle balance	13,278	15,995
Commercial Portfolio Segment [Member]
Recorded investment with no related allowance recorded	83	672
Unpaid principal balance with no related allowance recorded	97	1,205
Recorded investment with related allowance recorded	2,542	2,482
Unpaid principal balance with related allowance recorded	2,614	2,540
Related allowance	614	690
Recorded investment	2,625	3,154
Unpaid principle balance	2,711	3,745
Residential Portfolio Segment [Member]
Related allowance	343	391
Recorded investment	8,002	8,554
Unpaid principle balance	9,732	10,746
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Recorded investment with no related allowance recorded	6,047	5,895
Unpaid principal balance with no related allowance recorded	7,702	7,516
Recorded investment with related allowance recorded	1,346	1,628
Unpaid principal balance with related allowance recorded	1,382	1,678
Related allowance	155	199
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Recorded investment with no related allowance recorded	188	414
Unpaid principal balance with no related allowance recorded	224	897
Recorded investment with related allowance recorded		192
Unpaid principal balance with related allowance recorded		226
Related allowance		2
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Recorded investment with no related allowance recorded	45	45
Unpaid principal balance with no related allowance recorded	48	49
Recorded investment with related allowance recorded	376	380
Unpaid principal balance with related allowance recorded	376	380
Related allowance	188	190
Commercial Real Estate Portfolio Segment [Member]
Related allowance	121	77
Recorded investment	800	1,403
Unpaid principle balance	800	1,468
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Recorded investment with no related allowance recorded	800	600
Unpaid principal balance with no related allowance recorded	800	665
Related allowance	121
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Recorded investment with no related allowance recorded		803
Unpaid principal balance with no related allowance recorded		803
Consumer Portfolio Segment [Member]
Recorded investment with no related allowance recorded	35
Unpaid principal balance with no related allowance recorded	35
Recorded investment with related allowance recorded	35	36
Unpaid principal balance with related allowance recorded	35	36
Related allowance	$ 11	11
Recorded investment		36
Unpaid principle balance		$ 36