Note 3 - Investment Securities - Gross Unrealized Losses on Continuous Basis for Investment Securities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Less than 12 months Fair value	$ 4,474,342	$ 4,236,007
State and municipal	55,418	44,835
12 months or more Fair value	23,787,341	25,125,786
12 months or more Unrealized losses	982,580	653,866
Total Fair value	28,261,683	29,361,793
Total Unrealized losses	1,037,998	698,701
US States and Political Subdivisions Debt Securities [Member]
Less than 12 months Fair value	3,435,052	812,630
State and municipal	42,080	1,519
12 months or more Fair value	3,740,467	3,444,443
12 months or more Unrealized losses	177,781	130,520
Total Fair value	7,175,519	4,257,073
Total Unrealized losses	219,861	132,039
SBA Pools [Member]
Less than 12 months Fair value	443,288	551,780
State and municipal	6,707	1,903
12 months or more Fair value	2,276,084	2,109,832
12 months or more Unrealized losses	53,332	11,097
Total Fair value	2,719,372	2,661,612
Total Unrealized losses	60,039	13,000
Collateralized Mortgage Backed Securities [Member]
Less than 12 months Fair value	596,002	2,871,597
State and municipal	6,631	41,413
12 months or more Fair value	17,770,790	19,571,511
12 months or more Unrealized losses	751,467	512,249
Total Fair value	18,366,792	22,443,108
Total Unrealized losses	$ 758,098	$ 553,662