Note 5 - Loans - Age Analysis of Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Loans, past due	$ 4,310	$ 4,559
Loans, current	805,884	799,652
Gross loans	810,194	804,211
Recorded investment greater than 90 days and accruing
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, past due	1,237	999
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, past due	167	186
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, past due	2,906	3,374
Commercial Portfolio Segment [Member]
Loans, past due		51
Loans, current	145,635	153,793
Gross loans	145,635	153,844
Recorded investment greater than 90 days and accruing
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, past due		51
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, past due
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, past due
Commercial Real Estate Portfolio Segment [Member]
Gross loans	516,196	496,742
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans, past due
Loans, current	46,228	57,771
Gross loans	46,228	57,771
Recorded investment greater than 90 days and accruing
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Loans, past due	1,196	1,196
Loans, current	304,606	286,259
Gross loans	305,802	287,455
Recorded investment greater than 90 days and accruing
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Loans, past due	147	114
Loans, current	164,019	151,402
Gross loans	164,166	151,516
Recorded investment greater than 90 days and accruing
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Loans, past due
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Non-owner Occupied [Member]
Loans, past due
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Owner Occupied Loan [Member]
Loans, past due	147
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Loans, past due
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Non-owner Occupied [Member]
Loans, past due
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Owner Occupied Loan [Member]
Loans, past due
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Construction Loans [Member]
Loans, past due
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Non-owner Occupied [Member]
Loans, past due	1,196	1,196
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Owner Occupied Loan [Member]
Loans, past due		114
Residential Portfolio Segment [Member]
Gross loans	96,940	101,944
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Loans, past due	1,611	1,796
Loans, current	42,600	43,770
Gross loans	44,211	45,566
Recorded investment greater than 90 days and accruing
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Loans, past due	993	1,003
Loans, current	18,717	19,422
Gross loans	19,710	20,425
Recorded investment greater than 90 days and accruing
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Loans, past due	121	152
Loans, current	32,898	35,801
Gross loans	33,019	35,953
Recorded investment greater than 90 days and accruing
Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Loans, past due	664	567
Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Loans, past due	140	147
Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity Loan [Member]
Loans, past due	121	68
Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Loans, past due	90	80
Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Loans, past due
Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity Loan [Member]
Loans, past due		36
Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Loans, past due	857	1,149
Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Loans, past due	853	856
Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home Equity Loan [Member]
Loans, past due		48
Consumer Portfolio Segment [Member]
Loans, past due	242	247
Loans, current	51,181	51,434
Gross loans	51,423	51,681
Recorded investment greater than 90 days and accruing
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, past due	165	166
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, past due	77	70
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, past due		$ 11