Note 3 - Investment Securities - Securities in a Continuous Unrealized Loss Position (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Securities available for sale, less than 12 months, fair value	$ 180,624,957	$ 155,478,459
Securities available for sale, less than 12 months, gross unrealized losses	(3,545,097)	(2,160,027)
Securities available for sale, 12 months or more, fair value	13,274,726	85,161,627
Securities available for sale, 12 months or more, gross unrealized losses	(388,823)	(2,031,514)
Securities available for sale, fair value	193,899,683	240,640,086
Securities available for sale, gross unrealized losses	(3,933,920)	(4,191,541)
US States and Political Subdivisions Debt Securities [Member]
Securities held to maturity, less than 12 months, fair value	122,271,533	14,803,408
Securities held to maturity, less than 12 months, gross unrealized losses	(4,076,647)	(294,438)
Securities held to maturity, 12 months or more, fair value	13,010,803	19,927,581
Securities held to maturity, 12 months or more, gross unrealized losses	(618,087)	(878,994)
Securities held to maturity, fair value	135,282,336	34,730,989
Securities held to maturity, gross unrealized losses	(4,694,734)	(1,173,432)
Securities available for sale, less than 12 months, fair value	34,152,822	2,220,800
Securities available for sale, less than 12 months, gross unrealized losses	(618,462)	(31,807)
Securities available for sale, 12 months or more, fair value	338,099	848,329
Securities available for sale, 12 months or more, gross unrealized losses	(19,454)	(27,571)
Securities available for sale, fair value	34,490,921	3,069,129
Securities available for sale, gross unrealized losses	(637,916)	(59,378)
US Government Agencies Debt Securities [Member]
Securities available for sale, less than 12 months, fair value	21,788,139	112,900,327
Securities available for sale, less than 12 months, gross unrealized losses	(257,640)	(1,397,591)
Securities available for sale, 12 months or more, fair value	5,499,012	64,476,661
Securities available for sale, 12 months or more, gross unrealized losses	(72,945)	(1,450,970)
Securities available for sale, fair value	27,287,151	177,376,988
Securities available for sale, gross unrealized losses	(330,585)	(2,848,561)
Residential Mortgage Backed Securities [Member]
Securities available for sale, less than 12 months, fair value	121,506,582	40,356,921
Securities available for sale, less than 12 months, gross unrealized losses	(2,641,664)	(730,466)
Securities available for sale, 12 months or more, fair value	7,437,615	19,836,637
Securities available for sale, 12 months or more, gross unrealized losses	(296,424)	(552,973)
Securities available for sale, fair value	128,944,197	60,193,558
Securities available for sale, gross unrealized losses	(2,938,088)	(1,283,439)
Other Securities [Member]
Securities available for sale, less than 12 months, fair value	3,177,414	411
Securities available for sale, less than 12 months, gross unrealized losses	(27,331)	(163)
Securities available for sale, fair value	3,177,414	411
Securities available for sale, gross unrealized losses	$ (27,331)	$ (163)

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=73527792&loc=d3e27290-111563

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