Note 4 - Loans - Impaired Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Recorded investment with no related allowance recorded	$ 6,737	$ 7,626
Unpaid principal balance with no related allowance recorded	8,446	10,332
Recorded investment with related allowance recorded	4,678	5,521
Unpaid principal balance with related allowance recorded	4,804	5,663
Related allowance	1,165	1,169
Recorded investment	11,415	13,147
Unpaid principle balance	13,250	15,995
Commercial Portfolio Segment [Member]
Recorded investment with no related allowance recorded	75	672
Unpaid principal balance with no related allowance recorded	90	1,205
Recorded investment with related allowance recorded	2,703	2,482
Unpaid principal balance with related allowance recorded	2,791	2,540
Related allowance	753	690
Recorded investment	2,778	3,154
Unpaid principle balance	2,881	3,745
Residential Portfolio Segment [Member]
Related allowance	283	391
Recorded investment	7,805	8,554
Unpaid principle balance	9,536	10,746
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Recorded investment with no related allowance recorded	6,434	5,895
Unpaid principal balance with no related allowance recorded	8,085	7,516
Recorded investment with related allowance recorded	771	1,628
Unpaid principal balance with related allowance recorded	808	1,678
Related allowance	97	199
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Recorded investment with no related allowance recorded	184	414
Unpaid principal balance with no related allowance recorded	222	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	44	45
Unpaid principal balance with no related allowance recorded	49	49
Recorded investment with related allowance recorded	372	380
Unpaid principal balance with related allowance recorded	372	380
Related allowance	186	190
Commercial Real Estate Portfolio Segment [Member]
Related allowance	119	77
Recorded investment	799	1,403
Unpaid principle balance	799	1,468
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Recorded investment with no related allowance recorded		600
Unpaid principal balance with no related allowance recorded		665
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Recorded investment with related allowance recorded	799	803
Unpaid principal balance with related allowance recorded	799	803
Related allowance	119	77
Consumer Portfolio Segment [Member]
Recorded investment with related allowance recorded	33	36
Unpaid principal balance with related allowance recorded	34	36
Related allowance	10	11
Recorded investment	33	36
Unpaid principle balance	$ 34	$ 36