Note 5 - Loans and Allowance for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Valuation allowance	$ 1,268		$ 1,612
Loans recorded balance	17,513		20,552
Loans unpaid principal	18,746		21,870
Loans interest income recognized	5	$ 46
Loans average investment in impaired loans	18,647	12,978
Residential Portfolio Segment [Member] \| Real Estate Residential, One To Four Family Units [Member]
Loans without a specific valuation allowance, recorded balance	1,016		2
Loans without a specific valuation allowance, unpaid principal	1,016		2
Loans with a specific valuation allowance, recorded balance	1,197		4,518
Loans with a specific valuation allowance, unpaid principal	1,197		4,518
Valuation allowance	167		573
Loans recorded balance	2,213		4,520
Loans unpaid principal	2,213		4,520
Loans without a specific valuation allowance, average investment in impaired loans	1,111	1,961
Loans interest income recognized	1
Loans with a specific valuation allowance, average investment in impaired loans	2,352	2,353
Loans average investment in impaired loans	3,463	4,314
Residential Portfolio Segment [Member] \| Real Estate Residential, Multi Family Units [Member]
Loans without a specific valuation allowance, recorded balance	5,930		5,952
Loans without a specific valuation allowance, unpaid principal	5,930		5,952
Loans with a specific valuation allowance, recorded balance
Loans with a specific valuation allowance, unpaid principal
Valuation allowance
Loans recorded balance	5,930		5,952
Loans unpaid principal	5,930		5,952
Loans without a specific valuation allowance, average investment in impaired loans	5,934	509
Loans interest income recognized
Loans with a specific valuation allowance, average investment in impaired loans
Loans average investment in impaired loans	5,934	509
Residential Portfolio Segment [Member] \| Construction Loans [Member]
Loans without a specific valuation allowance, average investment in impaired loans		2,287
Loans interest income recognized
Loans with a specific valuation allowance, average investment in impaired loans	3,876	2,055
Loans average investment in impaired loans	3,876	4,342
Real Estate, Construction [Member]
Loans without a specific valuation allowance, recorded balance
Loans without a specific valuation allowance, unpaid principal
Loans with a specific valuation allowance, recorded balance	3,921		4,088
Loans with a specific valuation allowance, unpaid principal	5,154		5,321
Valuation allowance	551		552
Loans recorded balance	3,921		4,088
Loans unpaid principal	5,154		5,321
Commercial Real Estate Portfolio Segment [Member]
Loans without a specific valuation allowance, recorded balance	3,273		3,138
Loans without a specific valuation allowance, unpaid principal	3,273		3,138
Loans with a specific valuation allowance, recorded balance	708		1,232
Loans with a specific valuation allowance, unpaid principal	708		1,317
Valuation allowance	173		106
Loans recorded balance	3,981		4,370
Loans unpaid principal	3,981		4,455
Loans without a specific valuation allowance, average investment in impaired loans	3,440	2,326
Loans interest income recognized	4	46
Loans with a specific valuation allowance, average investment in impaired loans	717	27
Loans average investment in impaired loans	4,157	2,353
Commercial Portfolio Segment [Member]
Loans without a specific valuation allowance, recorded balance	136		216
Loans without a specific valuation allowance, unpaid principal	136		216
Loans with a specific valuation allowance, recorded balance	951		1,062
Loans with a specific valuation allowance, unpaid principal	951		1,062
Valuation allowance	345		363
Loans recorded balance	1,087		1,278
Loans unpaid principal	1,087		1,278
Loans without a specific valuation allowance, average investment in impaired loans	223	916
Loans interest income recognized
Loans with a specific valuation allowance, average investment in impaired loans	659	403
Loans average investment in impaired loans	882	1,319
Consumer and Other Loans [Member]
Loans without a specific valuation allowance, recorded balance	207		225
Loans without a specific valuation allowance, unpaid principal	207		225
Loans with a specific valuation allowance, recorded balance	174		119
Loans with a specific valuation allowance, unpaid principal	174		119
Valuation allowance	32		18
Loans recorded balance	381		344
Loans unpaid principal	381		$ 344
Consumer Portfolio Segment [Member]
Loans without a specific valuation allowance, average investment in impaired loans	229	9
Loans interest income recognized
Loans with a specific valuation allowance, average investment in impaired loans	106	132
Loans average investment in impaired loans	$ 335	$ 141

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
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