Note 5 - Loans and Allowance for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Impaired loans with no related allowance recorded, carrying amount	$ 708
Impaired loans with no related allowance recorded, unpaid principal balance	708
Impaired loans with an allowance recorded, carrying amount	831	791
Impaired loans with an allowance recorded, unpaid principal balance	831	791
Impaired loans, related allowances	166	98
Impaired loans, carrying amount	1,539	791
Impaired loans, unpaid principal balance	1,539	791
Impaired loans, average recorded investment	1,460	1,688
Impaired loans, interest income recognized	65	55
Impaired loans, interest income received	67	54
Real Estate [Member]
Impaired loans, average recorded investment		59
Impaired loans, interest income recognized		7
Impaired loans, interest income received		5
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	153
Impaired loans with an allowance recorded, unpaid principal balance	153
Impaired loans, related allowances	28
Impaired loans, carrying amount	226
Impaired loans, unpaid principal balance	226
Impaired loans, average recorded investment	70	902
Impaired loans, interest income recognized	8
Impaired loans, interest income received	8
Real Estate [Member] \| Secured by 1-4 Family Residential Properties [Member]
Impaired loans with no related allowance recorded, carrying amount	635
Impaired loans with no related allowance recorded, unpaid principal balance	635
Impaired loans with an allowance recorded, carrying amount	57	187
Impaired loans with an allowance recorded, unpaid principal balance	57	187
Impaired loans, related allowances	50	5
Impaired loans, carrying amount	692	187
Impaired loans, unpaid principal balance	692	187
Impaired loans, average recorded investment	794	190
Impaired loans, interest income recognized	16	13
Impaired loans, interest income received	16	14
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
Impaired loans with no related allowance recorded, unpaid principal balance
Impaired loans with an allowance recorded, carrying amount	511	532
Impaired loans with an allowance recorded, unpaid principal balance	511	532
Impaired loans, related allowances	1	21
Impaired loans, carrying amount	511	532
Impaired loans, unpaid principal balance	511	532
Impaired loans, average recorded investment	523	537
Impaired loans, interest income recognized	34	35
Impaired loans, interest income received	35	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	67	72
Impaired loans with an allowance recorded, unpaid principal balance	67	72
Impaired loans, related allowances	67	72
Impaired loans, carrying amount	67	72
Impaired loans, unpaid principal balance	67	$ 72
Impaired loans, average recorded investment	57
Impaired loans, interest income recognized	4
Impaired loans, interest income received	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	43
Impaired loans with an allowance recorded, unpaid principal balance	43
Impaired loans, related allowances	20
Impaired loans, carrying amount	43
Impaired loans, unpaid principal balance	43
Impaired loans, average recorded investment	15
Impaired loans, interest income recognized	3
Impaired loans, interest income received	$ 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=84173941&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=84173941&loc=d3e5258-111524

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- Definition

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

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