Note 4 - Allowance for Loan Losses - Segregated by Class of Loan (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Allowance for loan losses, beginning balance			$ 7,508	$ 8,923
Allowance for loan losses, charge-offs			(721)	(1,865)
Allowance for loan losses, recoveries			302	650
Provision for Loan Losses	$ 44		70	335
Allowance for loan losses, ending balance	7,159	8,043	7,159	8,043
Allowance for loan losses, provision	44		70	335
Commercial [Member] \| Commercial and Agricultural Portfolio Segment [Member]
Allowance for loan losses, beginning balance			447	456
Allowance for loan losses, charge-offs			(116)	(124)
Allowance for loan losses, recoveries			85	100
Provision for Loan Losses			28	(7)
Allowance for loan losses, ending balance	444	425	444	425
Allowance for loan losses, provision			28	(7)
Commercial [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance			3,874	5,751
Allowance for loan losses, charge-offs			(258)	(966)
Allowance for loan losses, recoveries			37	302
Provision for Loan Losses			753	(424)
Allowance for loan losses, ending balance	4,406	4,663	4,406	4,663
Allowance for loan losses, provision			753	(424)
Agricultural [Member] \| Commercial and Agricultural Portfolio Segment [Member]
Allowance for loan losses, beginning balance			186	168
Allowance for loan losses, charge-offs			(123)	(4)
Allowance for loan losses, recoveries			7	2
Provision for Loan Losses			192	72
Allowance for loan losses, ending balance	262	238	262	238
Allowance for loan losses, provision			192	72
Commercial Construction [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance			1,216	323
Allowance for loan losses, charge-offs			0	(49)
Allowance for loan losses, recoveries			38	162
Provision for Loan Losses			(1,172)	334
Allowance for loan losses, ending balance	82	770	82	770
Allowance for loan losses, provision			(1,172)	334
Residential Construction [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance				13
Allowance for loan losses, charge-offs			0	0
Allowance for loan losses, recoveries			0	0
Provision for Loan Losses			0	(2)
Allowance for loan losses, ending balance	0	11	0	11
Allowance for loan losses, provision			0	(2)
Residential [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance			968	1,396
Allowance for loan losses, charge-offs			(89)	(605)
Allowance for loan losses, recoveries			75	33
Provision for Loan Losses			112	148
Allowance for loan losses, ending balance	1,066	972	1,066	972
Allowance for loan losses, provision			112	148
Farmland [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance			780	722
Allowance for loan losses, charge-offs			0	0
Allowance for loan losses, recoveries			9	0
Provision for Loan Losses			79	137
Allowance for loan losses, ending balance	868	859	868	859
Allowance for loan losses, provision			79	137
Consumer [Member] \| Consumer and Other Portfolio Segment [Member]
Allowance for loan losses, beginning balance			34	80
Allowance for loan losses, charge-offs			(135)	(117)
Allowance for loan losses, recoveries			49	51
Provision for Loan Losses			82	70
Allowance for loan losses, ending balance	30	84	30	84
Allowance for loan losses, provision			82	70
Other [Member] \| Consumer and Other Portfolio Segment [Member]
Allowance for loan losses, beginning balance			3	14
Allowance for loan losses, charge-offs				0
Allowance for loan losses, recoveries			2	0
Provision for Loan Losses			(4)	7
Allowance for loan losses, ending balance	$ 1	$ 21	1	21
Allowance for loan losses, provision			$ (4)	$ 7

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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