Note 6 - Goodwill and Intangibles - Estimated Amortization Expense of Core Deposit Intangible (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net book value	$ 17,450,182	$ 9,078,953	$ 7,381,213
Core Deposits [Member]
2019	2,129,141
2020	2,084,985
2021	2,032,204
2022	1,970,792
2023	1,776,065
Thereafter	5,602,063
Net book value	15,595,250	$ 9,078,953	$ 7,381,213	$ 1,471,409
Customer Lists [Member]
2019	123,662
2020	123,662
2021	123,662
2022	123,662
2023	123,662
Thereafter	1,236,622
Net book value	$ 1,854,932