Note 5 - Loans and Leases - Allocation of Allowance for Loan and Lease Losses by Portfolio Segment Based on Methodology Used to Evaluate Loans and Leases for Impairment (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Individually evaluated for impairment $ 86 $ 693  
Collectively evaluated for impairment 17,400 15,164  
Allowance on loans and leases 17,486 15,857 $ 14,586
Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Acquired Loans [Member]      
Individually evaluated for impairment 28  
Collectively evaluated for impairment  
Allowance on loans and leases 28  
Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Originated Loans [Member]      
Individually evaluated for impairment 58 693  
Collectively evaluated for impairment 17,400 15,164  
Allowance on loans and leases 17,458 15,857  
Commercial Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment 6,227 5,199  
Allowance on loans and leases 6,227 5,199  
Commercial Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Acquired Loans [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment  
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Originated Loans [Member]      
Collectively evaluated for impairment 6,227 5,199  
Allowance on loans and leases 6,227 5,199  
Commercial Real Estate Portfolio Segment [Member] | Home Equity Loan [Member]      
Individually evaluated for impairment 115  
Collectively evaluated for impairment 1,255 1,192  
Allowance on loans and leases 1,255 1,307  
Commercial Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Acquired Loans [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment  
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Originated Loans [Member]      
Individually evaluated for impairment   115  
Collectively evaluated for impairment 1,255 1,192  
Allowance on loans and leases 1,255 1,307  
Commercial Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member]      
Individually evaluated for impairment 73 54  
Collectively evaluated for impairment 1,844 1,686  
Allowance on loans and leases 1,917 1,740  
Commercial Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Acquired Loans [Member]      
Individually evaluated for impairment 28  
Collectively evaluated for impairment  
Allowance on loans and leases 28  
Commercial Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Originated Loans [Member]      
Individually evaluated for impairment 45 54  
Collectively evaluated for impairment 1,844 1,686  
Allowance on loans and leases 1,889 1,740  
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment 2,233 1,324  
Allowance on loans and leases 2,233 1,324  
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Acquired Loans [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment  
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Originated Loans [Member]      
Collectively evaluated for impairment 2,233 1,324  
Allowance on loans and leases 2,233 1,324  
Commercial Portfolio Segment [Member]      
Individually evaluated for impairment 5 519  
Collectively evaluated for impairment 5,137 5,090  
Allowance on loans and leases 5,142 5,609 4,533
Commercial Portfolio Segment [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Portfolio Segment [Member] | Acquired Loans [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment  
Allowance on loans and leases  
Commercial Portfolio Segment [Member] | Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Commercial Portfolio Segment [Member] | Originated Loans [Member]      
Individually evaluated for impairment 5 519  
Collectively evaluated for impairment 5,137 5,090  
Allowance on loans and leases 5,142 5,609  
Consumer Portfolio Segment [Member]      
Individually evaluated for impairment 8 5  
Collectively evaluated for impairment 145 137  
Allowance on loans and leases 153 142 238
Consumer Portfolio Segment [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Consumer Portfolio Segment [Member] | Acquired Loans [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment  
Allowance on loans and leases  
Consumer Portfolio Segment [Member] | Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Consumer Portfolio Segment [Member] | Originated Loans [Member]      
Individually evaluated for impairment 8 5  
Collectively evaluated for impairment 145 137  
Allowance on loans and leases 153 142  
Finance Leases Portfolio Segment [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment 559 518  
Allowance on loans and leases 559 518 468
Finance Leases Portfolio Segment [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Finance Leases Portfolio Segment [Member] | Acquired Loans [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment  
Allowance on loans and leases  
Finance Leases Portfolio Segment [Member] | Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Finance Leases Portfolio Segment [Member] | Originated Loans [Member]      
Collectively evaluated for impairment 559 518  
Allowance on loans and leases 559 518  
Unallocated Financing Receivables [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment 18  
Allowance on loans and leases 18 $ 379
Unallocated Financing Receivables [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Unallocated Financing Receivables [Member] | Acquired Loans [Member]      
Individually evaluated for impairment  
Collectively evaluated for impairment  
Allowance on loans and leases  
Unallocated Financing Receivables [Member] | Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]      
Allowance on loans and leases  
Unallocated Financing Receivables [Member] | Originated Loans [Member]      
Collectively evaluated for impairment   18  
Allowance on loans and leases   $ 18