Note 8 - Premises and Equipment - Summary of Premises and Equipment and Applicable Depreciable Lives (Details) (Parentheticals)	12 Months Ended
	Dec. 31, 2018
Minimum [Member]
Useful lives for all premises and equipment (Year)	3 years
Maximum [Member]
Useful lives for all premises and equipment (Year)	40 years
Building [Member]
Useful lives for all premises and equipment (Year)	40 years
Furniture and Fixtures [Member] | Minimum [Member]
Useful lives for all premises and equipment (Year)	3 years
Furniture and Fixtures [Member] | Maximum [Member]
Useful lives for all premises and equipment (Year)	7 years