Note 5 - Loans - Types of Modifications (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Extended Maturity [Member]    
Financing receivable, modifications $ 211 $ 806
Extended Maturity and Capitalization of Taxes [Member]    
Financing receivable, modifications 95 100
Capitalization of Taxes [Member]    
Financing receivable, modifications 1,733
Principal Forbearance [Member]    
Financing receivable, modifications 306 2,639
Residential Portfolio Segment [Member] | Extended Maturity [Member]    
Financing receivable, modifications 159 710
Residential Portfolio Segment [Member] | Extended Maturity and Capitalization of Taxes [Member]    
Financing receivable, modifications 95 100
Residential Portfolio Segment [Member] | Capitalization of Taxes [Member]    
Financing receivable, modifications
Residential Portfolio Segment [Member] | Principal Forbearance [Member]    
Financing receivable, modifications 254 810
Commercial Real Estate Portfolio Segment [Member] | Extended Maturity [Member]    
Financing receivable, modifications
Commercial Real Estate Portfolio Segment [Member] | Extended Maturity and Capitalization of Taxes [Member]    
Financing receivable, modifications
Commercial Real Estate Portfolio Segment [Member] | Capitalization of Taxes [Member]    
Financing receivable, modifications 1,654
Commercial Real Estate Portfolio Segment [Member] | Principal Forbearance [Member]    
Financing receivable, modifications 1,654
Construction, Land Acquisition and Development [Member] | Extended Maturity [Member]    
Financing receivable, modifications 96
Construction, Land Acquisition and Development [Member] | Extended Maturity and Capitalization of Taxes [Member]    
Financing receivable, modifications
Construction, Land Acquisition and Development [Member] | Capitalization of Taxes [Member]    
Financing receivable, modifications
Construction, Land Acquisition and Development [Member] | Principal Forbearance [Member]    
Financing receivable, modifications 96
Commercial and Industrial [Member] | Extended Maturity [Member]    
Financing receivable, modifications 52
Commercial and Industrial [Member] | Extended Maturity and Capitalization of Taxes [Member]    
Financing receivable, modifications
Commercial and Industrial [Member] | Capitalization of Taxes [Member]    
Financing receivable, modifications 79
Commercial and Industrial [Member] | Principal Forbearance [Member]    
Financing receivable, modifications 52 79
Consumer Portfolio Segment [Member] | Extended Maturity [Member]    
Financing receivable, modifications
Consumer Portfolio Segment [Member] | Extended Maturity and Capitalization of Taxes [Member]    
Financing receivable, modifications
Consumer Portfolio Segment [Member] | Capitalization of Taxes [Member]    
Financing receivable, modifications
Consumer Portfolio Segment [Member] | Principal Forbearance [Member]    
Financing receivable, modifications
State and Political Subdivisions [Member] | Extended Maturity [Member]    
Financing receivable, modifications
State and Political Subdivisions [Member] | Extended Maturity and Capitalization of Taxes [Member]    
Financing receivable, modifications
State and Political Subdivisions [Member] | Capitalization of Taxes [Member]    
Financing receivable, modifications
State and Political Subdivisions [Member] | Principal Forbearance [Member]    
Financing receivable, modifications