Note 5 - Loans and Leases - Loan and Lease Modifications Categorized as Troubled Debt Restructurings (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Number of Contracts 16 7
Pre-Modification Outstanding Recorded Investment $ 2,772 $ 2,269
Post-Modification Outstanding Recorded Investment $ 2,779 $ 2,269
Contractual Interest Rate Reduction [Member]    
Number of Contracts
Extended Maturity [Member]    
Number of Contracts 4,000
Interest Rate Change and Term Extension [Member]    
Number of Contracts 2,000 2,000
Interest Rate Change and/or Interest-Only Period [Member]    
Number of Contracts 6,000 3,000
Contractual Payment Reduction (Leases only) [Member]    
Number of Contracts 3,000 2,000
Payment Deferral [Member]    
Number of Contracts 1,000
Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member]    
Number of Contracts 1  
Pre-Modification Outstanding Recorded Investment $ 1,256  
Post-Modification Outstanding Recorded Investment $ 1,256  
Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Contractual Interest Rate Reduction [Member]    
Number of Contracts  
Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Extended Maturity [Member]    
Number of Contracts 1,000  
Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Interest Rate Change and Term Extension [Member]    
Number of Contracts  
Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Interest Rate Change and/or Interest-Only Period [Member]    
Number of Contracts  
Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Contractual Payment Reduction (Leases only) [Member]    
Number of Contracts  
Real Estate Portfolio Segment [Member] | Commercial Mortgage [Member] | Payment Deferral [Member]    
Number of Contracts  
Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member]    
Number of Contracts 2 4
Pre-Modification Outstanding Recorded Investment $ 141 $ 2,181
Post-Modification Outstanding Recorded Investment $ 148 $ 2,181
Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Contractual Interest Rate Reduction [Member]    
Number of Contracts
Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Extended Maturity [Member]    
Number of Contracts
Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Interest Rate Change and Term Extension [Member]    
Number of Contracts 2,000 2,000
Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Interest Rate Change and/or Interest-Only Period [Member]    
Number of Contracts 2,000
Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Contractual Payment Reduction (Leases only) [Member]    
Number of Contracts
Real Estate Portfolio Segment [Member] | Residential Mortgage Loan [Member] | Payment Deferral [Member]    
Number of Contracts
Real Estate Portfolio Segment [Member] | Home Equity Loan [Member]    
Number of Contracts 6 1
Pre-Modification Outstanding Recorded Investment $ 265 $ 22
Post-Modification Outstanding Recorded Investment $ 265 $ 22
Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Contractual Interest Rate Reduction [Member]    
Number of Contracts
Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Extended Maturity [Member]    
Number of Contracts
Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Interest Rate Change and Term Extension [Member]    
Number of Contracts
Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Interest Rate Change and/or Interest-Only Period [Member]    
Number of Contracts 6,000 1,000
Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Contractual Payment Reduction (Leases only) [Member]    
Number of Contracts
Real Estate Portfolio Segment [Member] | Home Equity Loan [Member] | Payment Deferral [Member]    
Number of Contracts
Finance Leases Portfolio Segment [Member]    
Number of Contracts 3 2
Pre-Modification Outstanding Recorded Investment $ 104 $ 66
Post-Modification Outstanding Recorded Investment $ 104 $ 66
Finance Leases Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]    
Number of Contracts
Finance Leases Portfolio Segment [Member] | Extended Maturity [Member]    
Number of Contracts
Finance Leases Portfolio Segment [Member] | Interest Rate Change and Term Extension [Member]    
Number of Contracts
Finance Leases Portfolio Segment [Member] | Interest Rate Change and/or Interest-Only Period [Member]    
Number of Contracts
Finance Leases Portfolio Segment [Member] | Contractual Payment Reduction (Leases only) [Member]    
Number of Contracts 3,000 2,000
Finance Leases Portfolio Segment [Member] | Payment Deferral [Member]    
Number of Contracts
Commercial Portfolio Segment [Member]    
Number of Contracts 4  
Pre-Modification Outstanding Recorded Investment $ 1,006  
Post-Modification Outstanding Recorded Investment $ 1,006  
Commercial Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]    
Number of Contracts  
Commercial Portfolio Segment [Member] | Extended Maturity [Member]    
Number of Contracts 3,000  
Commercial Portfolio Segment [Member] | Interest Rate Change and Term Extension [Member]    
Number of Contracts  
Commercial Portfolio Segment [Member] | Interest Rate Change and/or Interest-Only Period [Member]    
Number of Contracts  
Commercial Portfolio Segment [Member] | Contractual Payment Reduction (Leases only) [Member]    
Number of Contracts  
Commercial Portfolio Segment [Member] | Payment Deferral [Member]    
Number of Contracts 1,000