Note 5 - Loans and Allowance for Loan Losses - Troubled Debt Restructurings Outcomes (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Troubled Debt Restructurings - Number of loans 6 4
Number of loans 6 4
Extended Maturity [Member]    
Troubled Debt Restructurings - Number of loans 5 4
Number of loans 5 4
Paid in Full [Member]    
Troubled Debt Restructurings - Number of loans 0 0
Troubled Debt Restructurings - Recorded Investment $ 0 $ 0
Number of loans 0 0
Troubled Debt Restructurings - Recorded Investment $ 0 $ 0
Paid in Full [Member] | Extended Maturity [Member]    
Troubled Debt Restructurings - Number of loans 0 0
Troubled Debt Restructurings - Recorded Investment $ 0 $ 0
Number of loans 0 0
Troubled Debt Restructurings - Recorded Investment $ 0 $ 0
Paying as Restructured [Member]    
Troubled Debt Restructurings - Number of loans 6 2
Troubled Debt Restructurings - Recorded Investment $ 2,606 $ 221
Number of loans 6 2
Troubled Debt Restructurings - Recorded Investment $ 2,606 $ 221
Paying as Restructured [Member] | Extended Maturity [Member]    
Troubled Debt Restructurings - Number of loans 6 2
Troubled Debt Restructurings - Recorded Investment $ 2,606 $ 221
Number of loans 6 2
Troubled Debt Restructurings - Recorded Investment $ 2,606 $ 221
Nonperforming Financial Instruments [Member]    
Troubled Debt Restructurings - Number of loans 2 2
Troubled Debt Restructurings - Recorded Investment $ 286 $ 96
Number of loans 2 2
Troubled Debt Restructurings - Recorded Investment $ 286 $ 96
Nonperforming Financial Instruments [Member] | Extended Maturity [Member]    
Troubled Debt Restructurings - Number of loans 2 2
Troubled Debt Restructurings - Recorded Investment $ 286 $ 96
Number of loans 2 2
Troubled Debt Restructurings - Recorded Investment $ 286 $ 96