Note 2 - Investment Securities - Securities in a Continuous Unrealized Loss Position (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Securities available for sale, fair value	$ 197,596,355	$ 193,899,683
Securities available for sale, gross unrealized losses	(2,359,129)	(3,933,920)
Securities available for sale, less than 12 months, fair value	183,645,208	180,624,957
Securities available for sale, less than 12 months, gross unrealized losses	(2,055,337)	(3,545,097)
Securities available for sale, 12 months or more, fair value	13,951,147	13,274,726
Securities available for sale, 12 months or more, gross unrealized losses	(303,792)	(388,823)
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale, fair value	25,914,485	34,490,921
Securities available for sale, gross unrealized losses	(252,541)	(637,916)
Securities held to maturity, less than 12 months, fair value	64,001,034	122,271,533
Securities held to maturity, less than 12 months, gross unrealized losses	(1,792,524)	(4,076,647)
Securities held to maturity, 12 months or more, fair value	30,641,106	13,010,803
Securities held to maturity, 12 months or more, gross unrealized losses	(1,449,702)	(618,087)
Securities held to maturity, fair value	94,642,140	135,282,336
Securities held to maturity, gross unrealized losses	(3,242,226)	(4,694,734)
Securities available for sale, less than 12 months, fair value	25,578,044	34,152,822
Securities available for sale, less than 12 months, gross unrealized losses	(234,044)	(618,462)
Securities available for sale, 12 months or more, fair value	336,441	338,099
Securities available for sale, 12 months or more, gross unrealized losses	(18,497)	(19,454)
US Government Agencies Debt Securities [Member]
Securities available for sale, fair value	32,568,525	27,287,151
Securities available for sale, gross unrealized losses	(189,347)	(330,585)
Securities available for sale, less than 12 months, fair value	27,793,290	21,788,139
Securities available for sale, less than 12 months, gross unrealized losses	(184,702)	(257,640)
Securities available for sale, 12 months or more, fair value	4,775,235	5,499,012
Securities available for sale, 12 months or more, gross unrealized losses	(4,645)	(72,945)
Residential Mortgage Backed Securities [Member]
Securities available for sale, fair value	138,186,545	128,944,197
Securities available for sale, gross unrealized losses	(1,894,691)	(2,938,088)
Securities available for sale, less than 12 months, fair value	129,347,074	121,506,582
Securities available for sale, less than 12 months, gross unrealized losses	(1,614,041)	(2,641,664)
Securities available for sale, 12 months or more, fair value	8,839,471	7,437,615
Securities available for sale, 12 months or more, gross unrealized losses	(280,650)	(296,424)
Other Securities [Member]
Securities available for sale, fair value	926,800	3,177,414
Securities available for sale, gross unrealized losses	(22,550)	(27,331)
Securities available for sale, less than 12 months, fair value	926,800	3,177,414
Securities available for sale, less than 12 months, gross unrealized losses	$ (22,550)	$ (27,331)

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

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