Note 7 - Loans and the Allowance for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Recorded investment, with an allowance recorded	$ 1,848	$ 2,718
Unpaid principal balance, with an allowance recorded	1,975	3,912
Related allowance	556	1,280
Average recorded investment, with an allowance recorded	1,955	1,241
Recorded investment, with no allowance recorded	9,999	9,642
Unpaid principal balance, with no allowance recorded	11,892	12,399
Average recorded investment, with no allowance recorded	10,885	13,583
Recorded investment	11,847	12,360
Unpaid principal balance	13,867	16,311
Average recorded investment	12,840	14,824
Commercial Real Estate Portfolio Segment [Member] \| Construction and Land [Member]
Recorded investment, with an allowance recorded
Unpaid principal balance, with an allowance recorded
Related allowance
Average recorded investment, with an allowance recorded	1	22
Recorded investment, with no allowance recorded	397	32
Unpaid principal balance, with no allowance recorded	420	56
Average recorded investment, with no allowance recorded	184	15
Recorded investment	397	32
Unpaid principal balance	420	56
Average recorded investment	185	37
Commercial Real Estate Portfolio Segment [Member] \| Farmland [Member]
Recorded investment, with an allowance recorded	20	0
Unpaid principal balance, with an allowance recorded	21	0
Related allowance	4	0
Average recorded investment, with an allowance recorded	21	0
Recorded investment, with no allowance recorded	202	112
Unpaid principal balance, with no allowance recorded	207	193
Average recorded investment, with no allowance recorded	177	9
Recorded investment	222	112
Unpaid principal balance	228	193
Average recorded investment	198	9
Commercial Real Estate Portfolio Segment [Member] \| Nonfarm Nonresidential [Member]
Recorded investment, with an allowance recorded	721	447
Unpaid principal balance, with an allowance recorded	738	501
Related allowance	52	47
Average recorded investment, with an allowance recorded	601	367
Recorded investment, with no allowance recorded	3,381	3,708
Unpaid principal balance, with no allowance recorded	3,693	3,833
Average recorded investment, with no allowance recorded	3,644	5,240
Recorded investment	4,102	4,155
Unpaid principal balance	4,431	4,334
Average recorded investment	4,245	5,607
Residential Portfolio Segment [Member] \| Real Estate Residential One- to Four-Family [Member]
Recorded investment, with an allowance recorded	136	363
Unpaid principal balance, with an allowance recorded	167	451
Related allowance	30	96
Average recorded investment, with an allowance recorded	163	303
Recorded investment, with no allowance recorded	2,395	2,365
Unpaid principal balance, with no allowance recorded	3,041	3,975
Average recorded investment, with no allowance recorded	2,531	2,708
Recorded investment	2,531	2,728
Unpaid principal balance	3,208	4,426
Average recorded investment	2,694	3,011
Residential Portfolio Segment [Member] \| Multi-family Residential [Member]
Recorded investment, with an allowance recorded	0	0
Unpaid principal balance, with an allowance recorded	0	0
Related allowance	0	0
Average recorded investment, with an allowance recorded	0	0
Recorded investment, with no allowance recorded	0	0
Unpaid principal balance, with no allowance recorded	0	0
Average recorded investment, with no allowance recorded	0	0
Recorded investment	0	0
Unpaid principal balance	0	0
Average recorded investment	0	0
Commercial Portfolio Segment [Member]
Recorded investment, with an allowance recorded	851	1,883
Unpaid principal balance, with an allowance recorded	926	2,935
Related allowance	421	1,112
Average recorded investment, with an allowance recorded	1,053	547
Recorded investment, with no allowance recorded	3,323	3,325
Unpaid principal balance, with no allowance recorded	4,173	4,198
Average recorded investment, with no allowance recorded	4,157	5,350
Recorded investment	4,174	5,208
Unpaid principal balance	5,099	7,133
Average recorded investment	5,210	5,897
Consumer Portfolio Segment [Member]
Recorded investment, with an allowance recorded	120	25
Unpaid principal balance, with an allowance recorded	123	25
Related allowance	49	25
Average recorded investment, with an allowance recorded	116	2
Recorded investment, with no allowance recorded	301	100
Unpaid principal balance, with no allowance recorded	358	144
Average recorded investment, with no allowance recorded	192	261
Recorded investment	421	125
Unpaid principal balance	481	169
Average recorded investment	$ 308	$ 263

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5258-111524

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