Note 5 - Loans - Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Recorded investment with no related allowance recorded	$ 7,626	$ 12,641
Unpaid principal balance with no related allowance recorded	10,332	16,440
Recorded investment with related allowance recorded	5,521	6,153
Unpaid principal balance with related allowance recorded	5,663	6,213
Related allowance	1,169	1,461
Recorded investment	13,147	18,794
Unpaid principle balance	15,995	22,653
Commercial Portfolio Segment [Member]
Recorded investment with no related allowance recorded	672	1,573
Unpaid principal balance with no related allowance recorded	1,205	2,438
Recorded investment with related allowance recorded	2,482	1,952
Unpaid principal balance with related allowance recorded	2,540	1,957
Related allowance	690	641
Recorded investment	3,154	3,525
Unpaid principle balance	3,745	4,395
Commercial Real Estate Portfolio Segment [Member]
Related allowance	77	85
Recorded investment	1,403	3,125
Unpaid principle balance	1,468	3,182
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Recorded investment with no related allowance recorded		1,196
Unpaid principal balance with no related allowance recorded		1,196
Recorded investment with related allowance recorded	803	808
Unpaid principal balance with related allowance recorded	803	808
Related allowance	77	21
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Recorded investment with no related allowance recorded	600	784
Unpaid principal balance with no related allowance recorded	665	841
Recorded investment with related allowance recorded		337
Unpaid principal balance with related allowance recorded		337
Related allowance		64
Residential Portfolio Segment [Member]
Related allowance	391	721
Recorded investment	8,554	11,894
Unpaid principle balance	10,746	14,820
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Recorded investment with no related allowance recorded	5,895	6,047
Unpaid principal balance with no related allowance recorded	7,516	7,685
Recorded investment with related allowance recorded	1,628	2,562
Unpaid principal balance with related allowance recorded	1,678	2,617
Related allowance	199	494
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Recorded investment with no related allowance recorded	414	1,914
Unpaid principal balance with no related allowance recorded	897	2,722
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	917
Unpaid principal balance with no related allowance recorded	49	1,342
Recorded investment with related allowance recorded	380	454
Unpaid principal balance with related allowance recorded	380	454
Related allowance	190	227
Consumer Portfolio Segment [Member]
Recorded investment with no related allowance recorded		210
Unpaid principal balance with no related allowance recorded		216
Recorded investment with related allowance recorded	36	40
Unpaid principal balance with related allowance recorded	36	40
Related allowance	11	14
Recorded investment	36	250
Unpaid principle balance	$ 36	$ 256