Note 11 - Other Borrowings and Unused Lines of Credit - Wholesale Repurchase Agreements (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Other borrowings	$ 66,000,000	$ 80,000,000
Whole sale Repurchase Agreements [Member]
Other borrowings	$ 35,000,000	$ 45,000,000
Weighted average interest rate at year end	2.76%	2.81%
Whole sale Repurchase Agreements [Member] | Maturing in 2017 [Member]
Other borrowings		$ 10,000,000
Weighted average interest rate at year end		3.00%
Whole sale Repurchase Agreements [Member] | Maturing in 2019 [Member]
Other borrowings	$ 10,000,000	$ 10,000,000
Weighted average interest rate at year end	3.44%	3.44%
Whole sale Repurchase Agreements [Member] | Maturing in 2020 [Member]
Other borrowings	$ 25,000,000	$ 25,000,000
Weighted average interest rate at year end	2.48%	2.48%