Note 2 - Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Beginning balance	$ 28,726	$ 27,174	$ 27,174
Provision	6,631	1,354	2,040
Charge-offs	(729)	(853)	(1,363)
Recoveries	813	710	875
Ending balance	35,441	28,385	28,726
Ending balance individually evaluated for impairment	768	1,704	1,136
Ending balance collectively evaluated for impairment	34,673	26,681	27,590
Loans and Leases Receivable, Gross, Total	2,297,104	1,989,765	2,093,042
Ending balance individually evaluated for impairment	2,382	5,843	5,040
Ending balance collectively evaluated for impairment	2,294,722	1,983,922	2,088,002
Real Estate Portfolio Segment [Member]
Loans and Leases Receivable, Gross, Total	2,035,408		1,929,325
Commercial Portfolio Segment [Member]
Beginning balance	1,044	622	622
Provision	200	338	422
Charge-offs	(8)	(15)	(15)
Recoveries	0	15	15
Ending balance	1,236	960	1,044
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	1,236	960	1,044
Loans and Leases Receivable, Gross, Total	189,655	90,450	98,265
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	189,655	90,450	98,265
Agricultural Installment and Other Portfolio Segment [Member]
Beginning balance	1,111	867	867
Provision	697	813	1,041
Charge-offs	(714)	(824)	(1,160)
Recoveries	382	267	363
Ending balance	1,476	1,123	1,111
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	1,476	1,123	1,111
Loans and Leases Receivable, Gross, Total	72,041	67,602	65,452
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	72,041	67,602	65,452
Residential 1 to 4 Family [Member] \| Real Estate Portfolio Segment [Member]
Beginning balance	7,144	6,297	6,297
Provision	820	285	838
Charge-offs	0	(14)	(15)
Recoveries	17	20	24
Ending balance	7,981	6,588	7,144
Ending balance individually evaluated for impairment	612	789	795
Ending balance collectively evaluated for impairment	7,369	5,799	6,349
Loans and Leases Receivable, Gross, Total	531,485	468,772	511,250
Ending balance individually evaluated for impairment	1,403	2,648	2,569
Ending balance collectively evaluated for impairment	530,082	466,124	508,681
Multifamily Real Estate [Member] \| Real Estate Portfolio Segment [Member]
Beginning balance	1,117	1,481	1,481
Provision	528	(261)	(364)
Charge-offs	0	0	0
Recoveries	0	0	0
Ending balance	1,645	1,220	1,117
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	1,645	1,220	1,117
Loans and Leases Receivable, Gross, Total	123,650	106,072	97,104
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	123,650	106,072	97,104
Commercial Real Estate [Member] \| Real Estate Portfolio Segment [Member]
Beginning balance	11,114	9,753	9,753
Provision	3,865	1,632	1,484
Charge-offs	0	0	(173)
Recoveries	300	0	50
Ending balance	15,279	11,385	11,114
Ending balance individually evaluated for impairment	156	915	341
Ending balance collectively evaluated for impairment	15,123	10,470	10,773
Loans and Leases Receivable, Gross, Total	846,521	745,080	793,379
Ending balance individually evaluated for impairment	979	3,195	2,471
Ending balance collectively evaluated for impairment	845,542	741,885	790,908
Construction Loans [Member] \| Real Estate Portfolio Segment [Member]
Beginning balance	5,997	7,084	7,084
Provision	513	(1,564)	(1,510)
Charge-offs	0	0	0
Recoveries	54	408	423
Ending balance	6,564	5,928	5,997
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	6,564	5,928	5,997
Loans and Leases Receivable, Gross, Total	430,599	410,494	425,185
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	430,599	410,494	425,185
Farmland [Member] \| Real Estate Portfolio Segment [Member]
Beginning balance	187	221	221
Provision	(23)	(23)	(34)
Charge-offs	0	0	0
Recoveries	0	0	0
Ending balance	164	198	187
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	164	198	187
Loans and Leases Receivable, Gross, Total	16,422	20,425	19,268
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	16,422	20,425	19,268
Second Mortgages [Member] \| Real Estate Portfolio Segment [Member]
Beginning balance	123	118	118
Provision	(27)	11	5
Charge-offs	0	0	0
Recoveries	19	0	0
Ending balance	115	129	123
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	115	129	123
Loans and Leases Receivable, Gross, Total	9,239	11,204	10,760
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	9,239	11,204	10,760
Home Equity Line of Credit [Member] \| Real Estate Portfolio Segment [Member]
Beginning balance	889	731	731
Provision	58	123	158
Charge-offs	(7)	0	0
Recoveries	41	0	0
Ending balance	981	854	889
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	981	854	889
Loans and Leases Receivable, Gross, Total	77,492	69,666	72,379
Ending balance individually evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	$ 77,492	$ 69,666	$ 72,379

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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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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