Note 5 - Allowance for Loan Losses - Segregated by Class of Loan (Details) - USD ($)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for loan losses, beginning balance	$ 8,603,905	$ 8,802,316	$ 11,805,986
Allowance for loan losses, charge-offs	(2,087,850)	(2,083,347)	(5,104,491)
Allowance for loan losses, recoveries	1,345,238	1,019,436	792,821
Provision for Loan Losses	1,062,000	865,500	1,308,000
Allowance for loan losses, ending balance	8,923,293	8,603,905	8,802,316
Commercial [Member] \| Commercial and Agricultural Portfolio Segment [Member]
Allowance for loan losses, beginning balance	855,364	497,561	1,017,073
Allowance for loan losses, charge-offs	(304,918)	(454,971)	(624,944)
Allowance for loan losses, recoveries	66,738	52,111	76,002
Provision for Loan Losses	(160,987)	760,663	29,430
Allowance for loan losses, ending balance	456,197	855,364	497,561
Commercial [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	3,850,527	3,664,777	4,379,276
Allowance for loan losses, charge-offs	(992,067)	(275,297)	(1,326,825)
Allowance for loan losses, recoveries	206,154	270,003	90,042
Provision for Loan Losses	2,686,384	191,044	522,284
Allowance for loan losses, ending balance	5,750,998	3,850,527	3,664,777
Agricultural [Member] \| Commercial and Agricultural Portfolio Segment [Member]
Allowance for loan losses, beginning balance	203,091	304,172	293,886
Allowance for loan losses, charge-offs	(19,258)	(5,000)
Allowance for loan losses, recoveries	4,150	3,600	2,700
Provision for Loan Losses	(20,291)	(99,681)	7,586
Allowance for loan losses, ending balance	167,692	203,091	304,172
Commercial Construction [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	690,766	1,222,695	1,782,179
Allowance for loan losses, charge-offs	(25,318)	(97,698)	(1,543,099)
Allowance for loan losses, recoveries	814,586	485,834	485,005
Provision for Loan Losses	(1,157,309)	(920,065)	498,610
Allowance for loan losses, ending balance	322,725	690,766	1,222,695
Residential Construction [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	19,890	138,092	138,092
Allowance for loan losses, charge-offs
Allowance for loan losses, recoveries
Provision for Loan Losses	(6,399)	(118,202)
Allowance for loan losses, ending balance	13,491	19,890	138,092
Residential [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	1,990,355	2,425,327	3,278,269
Allowance for loan losses, charge-offs	(361,630)	(929,668)	(1,033,966)
Allowance for loan losses, recoveries	49,660	109,626	31,127
Provision for Loan Losses	(282,286)	385,070	149,897
Allowance for loan losses, ending balance	1,396,099	1,990,355	2,425,327
Farmland [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	911,692	103,800	311,494
Allowance for loan losses, charge-offs	(119,576)	(40,000)	(233,580)
Allowance for loan losses, recoveries	145,000	20,000	20,000
Provision for Loan Losses	(214,785)	827,892	5,886
Allowance for loan losses, ending balance	722,331	911,692	103,800
Consumer [Member] \| Consumer and Other Portfolio Segment [Member]
Allowance for loan losses, beginning balance	63,377	66,914	243,253
Allowance for loan losses, charge-offs	(265,083)	(255,062)	(342,077)
Allowance for loan losses, recoveries	52,629	61,976	72,477
Provision for Loan Losses	229,342	189,549	93,261
Allowance for loan losses, ending balance	80,265	63,377	66,914
Other [Member] \| Consumer and Other Portfolio Segment [Member]
Allowance for loan losses, beginning balance	18,843	378,978	362,464
Allowance for loan losses, charge-offs		(25,651)
Allowance for loan losses, recoveries	6,321	16,286	15,468
Provision for Loan Losses	(11,669)	(350,770)	1,046
Allowance for loan losses, ending balance	$ 13,495	$ 18,843	$ 378,978

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of expense related to estimated loss from loan and lease transactions.

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