Note 25 - Unaudited Quarterly Operating Results - Quarterly Financial Data (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest income	$ 11,532,388	$ 13,377,875	$ 10,379,125	$ 7,956,316	$ 7,902,636	$ 7,525,187	$ 7,241,508	$ 6,771,402	$ 43,245,704	$ 29,440,733	$ 25,389,326
Interest expense	2,946,828	2,648,869	2,406,858	1,925,064	2,087,594	1,473,190	1,352,309	1,173,461	9,927,619	6,086,554	4,177,012
Net interest income	8,585,560	10,729,006	7,972,267	6,031,252	5,815,042	6,051,997	5,889,199	5,597,941	33,318,085	23,354,179	21,212,314
Provision for loan losses	300,000	200,000	500,000	225,000	250,000	450,000	575,000	475,000	1,225,000	1,750,000	1,375,000
Gain on loans and investment securities	609,521	858,254	831,919	553,602	799,123	858,826	710,665	539,102
Other noninterest income, net	1,207,810	603,504	1,121,893	765,437	760,903	712,043	656,395	690,263
Noninterest expense	7,093,992	6,665,849	10,222,637	5,475,855	5,603,718	5,011,832	4,567,916	4,419,620	29,458,333	19,603,086	17,100,746
Income before income taxes	3,008,899	5,324,915	(796,558)	1,649,436	1,521,350	2,161,034	2,113,343	1,932,686	9,186,692	7,728,413	7,606,775
Provision for income taxes	624,023	1,390,673	(453,574)	293,691	1,102,883	443,651	520,770	503,445	1,854,813	2,570,749	2,012,764
Net income available to common shareholders	$ 2,384,876	$ 3,934,242	$ (342,984)	$ 1,355,745	$ 418,467	$ 1,717,383	$ 1,592,573	$ 1,429,241	$ 7,331,879	$ 5,157,664	$ 5,594,011
Basic income per common share (in dollars per share)	$ 0.54	$ 0.89	$ (0.08)	$ 0.31	$ 0.10	$ 0.39	$ 0.36	$ 0.33	$ 1.66	$ 1.18	$ 1.28
Diluted income per common share (in dollars per share)	$ 0.53	$ 0.88	$ (0.08)	$ 0.30	$ 0.09	$ 0.39	$ 0.36	$ 0.32	$ 1.64	$ 1.16	$ 1.27