Note 1 - Summary of Significant Accounting Policies - Premises and Equipment Estimated Useful Lives (Details)
12 Months Ended
Dec. 31, 2016
Building and Building Improvements [Member] | Minimum [Member]  
Property, Plant and Equipment, Useful Life (Year) 10 years
Building and Building Improvements [Member] | Maximum [Member]  
Property, Plant and Equipment, Useful Life (Year) 40 years
Furniture and Fixtures [Member] | Minimum [Member]  
Property, Plant and Equipment, Useful Life (Year) 5 years
Furniture and Fixtures [Member] | Maximum [Member]  
Property, Plant and Equipment, Useful Life (Year) 10 years
Leasehold Improvements [Member]  
Property, Plant and Equipment, Useful Life (Year) 18 years
Computer Equipment [Member] | Minimum [Member]  
Property, Plant and Equipment, Useful Life (Year) 3 years
Computer Equipment [Member] | Maximum [Member]  
Property, Plant and Equipment, Useful Life (Year) 5 years