Note 5 - Loans and Allowance for Loan Losses - Past Due Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans past due	$ 4,355	$ 2,564
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans past due	162	141
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans past due	226	35
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans past due	414
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans past due	370	31
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due	1,030	727
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans past due	174	75
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due	1,120	420
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due	7,851	3,993
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans past due	1,677	1,484
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans past due	338	33
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans past due	316	334
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans past due		2
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans past due	230	88
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due	228	197
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans past due
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due	199	104
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due	2,988	2,242
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans past due	2,164	1,708
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans past due	1,508	371
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans past due	2,235	2,737
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans past due	182	769
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans past due	602	1,077
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due	63	36
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans past due		76
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due	56	4
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due	6,810	6,778
Residential Portfolio Segment [Member]
Loans past due	8,196	5,756
Loans, current	265,139	218,119
Loans	273,335	223,875
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans past due	2,008	545
Loans, current	80,196	72,913
Loans	82,204	73,458
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans past due	2,777	3,106
Loans, current	96,146	68,896
Loans	98,923	72,002
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans past due	596	771
Loans, current	33,898	23,081
Loans	34,494	23,852
Commercial Real Estate Portfolio Segment [Member]
Loans	215,621	169,312
Commercial and Industrial Portfolio Segment [Member]
Loans past due	1,202	1,196
Loans, current	95,990	80,740
Loans	97,192	81,936
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due	1,321	960
Loans, current	57,038	43,606
Loans	58,359	44,566
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans past due	174	151
Loans, current	19,985	20,690
Loans	20,159	20,841
Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due	1,375	528
Loans, current	55,546	44,694
Loans	56,921	45,222
Consumer Portfolio Segment [Member]
Loans	135,439	110,629
Loans past due	17,649	13,013
Loans, current	703,938	572,739
Loans	$ 721,587	$ 585,752