Note 5 - Loans and Allowance for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2019	Dec. 31, 2018
Impaired loans with no related allowance recorded, carrying amount	$ 1,793	$ 708
Impaired loans with no related allowance recorded, unpaid principal balance	1,793	708
Impaired loans with an allowance recorded, carrying amount	543	831
Impaired loans with an allowance recorded, unpaid principal balance	543	831
Impaired loans, related allowances	188	166
Impaired loans, carrying amount	2,336	1,539
Impaired loans, unpaid principal balance	2,336	1,539
Impaired loans, average recorded investment	2,067	1,460
Impaired loans, interest income recognized	62	65
Impaired loans, interest income received	56	67
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Impaired loans with no related allowance recorded, carrying amount		73
Impaired loans with no related allowance recorded, unpaid principal balance		73
Impaired loans with an allowance recorded, carrying amount	421	153
Impaired loans with an allowance recorded, unpaid principal balance	421	153
Impaired loans, related allowances	95	28
Impaired loans, carrying amount	421	226
Impaired loans, unpaid principal balance	421	226
Impaired loans, average recorded investment	181	70
Impaired loans, interest income recognized	7	8
Impaired loans, interest income received	6	8
Real Estate [Member] \| Secured by 1-4 Family Residential Properties [Member]
Impaired loans with no related allowance recorded, carrying amount	1,289	635
Impaired loans with no related allowance recorded, unpaid principal balance	1,289	635
Impaired loans with an allowance recorded, carrying amount	22	57
Impaired loans with an allowance recorded, unpaid principal balance	22	57
Impaired loans, related allowances	16	50
Impaired loans, carrying amount	1,311	692
Impaired loans, unpaid principal balance	1,311	692
Impaired loans, average recorded investment	1,062	794
Impaired loans, interest income recognized	31	16
Impaired loans, interest income received	28	16
Real Estate [Member] \| Secured by Multi-family Residential Properties [Member]
Impaired loans with no related allowance recorded, carrying amount
Impaired loans with no related allowance recorded, unpaid principal balance
Impaired loans with an allowance recorded, carrying amount
Impaired loans with an allowance recorded, unpaid principal balance
Impaired loans, related allowances
Impaired loans, carrying amount
Impaired loans, unpaid principal balance
Impaired loans, average recorded investment
Impaired loans, interest income recognized
Impaired loans, interest income received
Real Estate [Member] \| Secured by Non-farm, Non-residential Properties [Member]
Impaired loans with no related allowance recorded, carrying amount	504
Impaired loans with no related allowance recorded, unpaid principal balance	504
Impaired loans with an allowance recorded, carrying amount		511
Impaired loans with an allowance recorded, unpaid principal balance		511
Impaired loans, related allowances		1
Impaired loans, carrying amount	504	511
Impaired loans, unpaid principal balance	504	511
Impaired loans, average recorded investment	718	523
Impaired loans, interest income recognized	19	34
Impaired loans, interest income received	18	35
Real Estate [Member] \| Other Real Estate Loans [Member]
Impaired loans, average recorded investment		1
Impaired loans, interest income recognized
Impaired loans, interest income received
Commercial and Industrial Loans [Member]
Impaired loans with no related allowance recorded, carrying amount
Impaired loans with no related allowance recorded, unpaid principal balance
Impaired loans with an allowance recorded, carrying amount	65	67
Impaired loans with an allowance recorded, unpaid principal balance	65	67
Impaired loans, related allowances	65	67
Impaired loans, carrying amount	65	67
Impaired loans, unpaid principal balance	65	67
Impaired loans, average recorded investment	66	57
Impaired loans, interest income recognized	4	4
Impaired loans, interest income received	3	5
Consumer Portfolio Segment [Member]
Impaired loans with no related allowance recorded, carrying amount
Impaired loans with no related allowance recorded, unpaid principal balance
Impaired loans with an allowance recorded, carrying amount	35	43
Impaired loans with an allowance recorded, unpaid principal balance	35	43
Impaired loans, related allowances	12	20
Impaired loans, carrying amount	35	43
Impaired loans, unpaid principal balance	35	43
Impaired loans, average recorded investment	40	15
Impaired loans, interest income recognized	1	3
Impaired loans, interest income received	$ 1	$ 3

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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5258-111524

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953550-111524

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