Note 5 - Allowance for Loan Losses - Segregated by Class of Loan (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Allowance for loan losses, beginning balance	$ 7,277	$ 7,508
Allowance for loan losses, charge-offs	(944)	(141)
Allowance for loan losses, recoveries	125	74
Allowance for loan losses, provision	131	26
Allowance for loan losses, ending balance	6,589	7,467
Allowance for loan losses, provision	131	26
Provision for Loan Losses	131	26
Commercial [Member] \| Commercial and Agricultural Portfolio Segment [Member]
Allowance for loan losses, beginning balance	370	447
Allowance for loan losses, charge-offs	(97)	(4)
Allowance for loan losses, recoveries	6	8
Allowance for loan losses, provision	(38)	19
Allowance for loan losses, ending balance	241	470
Allowance for loan losses, provision	(38)	19
Provision for Loan Losses	(38)	19
Commercial [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	4,549	3,874
Allowance for loan losses, charge-offs	(56)
Allowance for loan losses, recoveries	33	4
Allowance for loan losses, provision	(152)	(551)
Allowance for loan losses, ending balance	4,374	3,327
Allowance for loan losses, provision	(152)	(551)
Provision for Loan Losses	(152)	(551)
Agricultural [Member] \| Commercial and Agricultural Portfolio Segment [Member]
Allowance for loan losses, beginning balance	248	186
Allowance for loan losses, charge-offs	0	(17)
Allowance for loan losses, recoveries	0	1
Allowance for loan losses, provision	(23)	32
Allowance for loan losses, ending balance	225	202
Allowance for loan losses, provision	(23)	32
Provision for Loan Losses	(23)	32
Commercial Construction [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	115	1,216
Allowance for loan losses, charge-offs	(29)
Allowance for loan losses, recoveries	17	20
Allowance for loan losses, provision	(88)	187
Allowance for loan losses, ending balance	15	1,423
Allowance for loan losses, provision	(88)	187
Provision for Loan Losses	(88)	187
Residential Construction [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	16
Allowance for loan losses, charge-offs	0	0
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provision	(11)
Allowance for loan losses, ending balance	5
Allowance for loan losses, provision	(11)
Provision for Loan Losses	(11)
Residential [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	1,181	968
Allowance for loan losses, charge-offs	(629)	(61)
Allowance for loan losses, recoveries	49	12
Allowance for loan losses, provision	348	270
Allowance for loan losses, ending balance	949	1,189
Allowance for loan losses, provision	348	270
Provision for Loan Losses	348	270
Farmland [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	702	780
Allowance for loan losses, charge-offs	(63)
Allowance for loan losses, recoveries	1	1
Allowance for loan losses, provision	48	24
Allowance for loan losses, ending balance	688	805
Allowance for loan losses, provision	48	24
Provision for Loan Losses	48	24
Consumer [Member] \| Consumer and Other Portfolio Segment [Member]
Allowance for loan losses, beginning balance	86	34
Allowance for loan losses, charge-offs	(70)	(59)
Allowance for loan losses, recoveries	17	28
Allowance for loan losses, provision	36	45
Allowance for loan losses, ending balance	69	48
Allowance for loan losses, provision	36	45
Provision for Loan Losses	36	45
Other [Member] \| Consumer and Other Portfolio Segment [Member]
Allowance for loan losses, beginning balance	10	3
Allowance for loan losses, charge-offs	0
Allowance for loan losses, recoveries	2
Allowance for loan losses, provision	11
Allowance for loan losses, ending balance	23	3
Allowance for loan losses, provision	11
Provision for Loan Losses	$ 11

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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