Note 11 - Other Borrowings and Unused Lines of Credit - Wholesale Repurchase Agreements (Details)	12 Months Ended
	Dec. 31, 2018 USD ($) loan	Dec. 31, 2017 USD ($)
Number of term loans | loan	2
Other borrowings	$ 72,032,318	$ 66,000,000
Wholesale structured repurchase agreements
Other borrowings	$ 35,000,000	$ 35,000,000
Weighted average interest rate at year end	2.80%	2.76%
Wholesale structured repurchase agreements | Maturing in 2019
Other borrowings	$ 10,000,000	$ 10,000,000
Weighted average interest rate at year end	3.59%	3.44%
Wholesale structured repurchase agreements | Maturing in 2020
Other borrowings	$ 25,000,000	$ 25,000,000
Weighted average interest rate at year end	2.48%	2.48%