Note 4 - Loans and Allowance for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Valuation allowance	$ 426		$ 426		$ 421
Loans with a specific valuation allowance, recorded balance	10,451		10,451		19,014
Loans unpaid principal	10,451		10,451		20,985
Loans average investment in impaired loans	14,341	$ 11,454	16,458	$ 10,946
Loans interest income recognized	5	5	9	7
Residential Portfolio Segment [Member] \| Real Estate Residential, One To Four Family Units [Member]
Loans without a specific valuation allowance, recorded balance	1,376		1,376		2,780
Loans without a specific valuation allowance, unpaid principal	1,376		1,376		2,780
Loans with a specific valuation allowance, recorded balance	109		109		330
Loans with a specific valuation allowance, unpaid principal	109		109		330
Valuation allowance	53		53		112
Loans with a specific valuation allowance, recorded balance	1,485		1,485		3,110
Loans unpaid principal	1,485		1,485		3,110
Loans without a specific valuation allowance, average investment in impaired loans	2,065	1,122	2,372	1,106
Loans without a specific valuation allowance, interest income recognized	0	0	0	0
Loans with a specific valuation allowance, average investment in impaired loans	144	1,274	183	1,224
Loans with a specific valuation allowance, interest income recognized	0	0	0	0
Loans average investment in impaired loans	2,209	2,396	2,555	2,330
Loans interest income recognized	0	0	0	0
Residential Portfolio Segment [Member] \| Real Estate Residential, Multi Family Units [Member]
Loans without a specific valuation allowance, recorded balance	0		0		0
Loans without a specific valuation allowance, unpaid principal	0		0		0
Loans with a specific valuation allowance, recorded balance	0		0		0
Loans with a specific valuation allowance, unpaid principal	0		0		0
Valuation allowance	0		0		0
Loans with a specific valuation allowance, recorded balance	0		0		0
Loans unpaid principal	0		0		0
Loans without a specific valuation allowance, average investment in impaired loans	0	0	0	0
Loans without a specific valuation allowance, interest income recognized	0	0	0	0
Loans with a specific valuation allowance, average investment in impaired loans	0	0	0	0
Loans with a specific valuation allowance, interest income recognized	0	0	0	0
Loans average investment in impaired loans	0	0	0	0
Loans interest income recognized	0	0	0	0
Residential Portfolio Segment [Member] \| Construction Loans [Member]
Loans without a specific valuation allowance, average investment in impaired loans	4,007	0	4,544	0
Loans without a specific valuation allowance, interest income recognized	0	0	0	0
Loans with a specific valuation allowance, average investment in impaired loans	867	4,437	916	4,188
Loans with a specific valuation allowance, interest income recognized	0	0	0	0
Loans average investment in impaired loans	4,874	4,437	5,460	4,188
Loans interest income recognized	0	0	0	0
Real Estate, Construction [Member]
Loans without a specific valuation allowance, recorded balance	2,025		2,025		5,081
Loans without a specific valuation allowance, unpaid principal	2,025		2,025		5,081
Loans with a specific valuation allowance, recorded balance	866		866		1,158
Loans with a specific valuation allowance, unpaid principal	866		866		3,129
Valuation allowance	203		203		114
Loans with a specific valuation allowance, recorded balance	2,891		2,891		6,239
Loans unpaid principal	2,891		2,891		8,210
Commercial Real Estate Portfolio Segment [Member]
Loans without a specific valuation allowance, recorded balance	3,298		3,298		3,419
Loans without a specific valuation allowance, unpaid principal	3,298		3,298		3,419
Loans with a specific valuation allowance, recorded balance	516		516		801
Loans with a specific valuation allowance, unpaid principal	516		516		801
Valuation allowance	90		90		117
Loans with a specific valuation allowance, recorded balance	3,814		3,814		4,220
Loans unpaid principal	3,814		3,814		4,220
Loans without a specific valuation allowance, average investment in impaired loans	3,334	3,247	3,362	3,006
Loans without a specific valuation allowance, interest income recognized	2	0	4	0
Loans with a specific valuation allowance, average investment in impaired loans	608	191	701	236
Loans with a specific valuation allowance, interest income recognized	0	0	0	0
Loans average investment in impaired loans	3,942	3,438	4,063	3,242
Loans interest income recognized	2	0	4	0
Commercial Portfolio Segment [Member]
Loans without a specific valuation allowance, recorded balance	1,750		1,750		4,902
Loans without a specific valuation allowance, unpaid principal	1,750		1,750		4,902
Loans with a specific valuation allowance, recorded balance	319		319		341
Loans with a specific valuation allowance, unpaid principal	319		319		341
Valuation allowance	64		64		63
Loans with a specific valuation allowance, recorded balance	2,069		2,069		5,243
Loans unpaid principal	2,069		2,069		5,243
Loans without a specific valuation allowance, average investment in impaired loans	2,816	0	3,860	9
Loans without a specific valuation allowance, interest income recognized	0	0	0	0
Loans with a specific valuation allowance, average investment in impaired loans	320	928	324	916
Loans with a specific valuation allowance, interest income recognized	0	0	0	0
Loans average investment in impaired loans	3,136	928	4,184	925
Loans interest income recognized	0	0	0	0
Consumer Portfolio Segment [Member]
Loans without a specific valuation allowance, average investment in impaired loans	102	112	104	105
Loans without a specific valuation allowance, interest income recognized	3	5	5	7
Loans with a specific valuation allowance, average investment in impaired loans	78	143	92	156
Loans with a specific valuation allowance, interest income recognized	0	0	0	0
Loans average investment in impaired loans	180	255	196	261
Loans interest income recognized	3	$ 5	5	$ 7
Consumer and Other Loans [Member]
Loans without a specific valuation allowance, recorded balance	95		95		100
Loans without a specific valuation allowance, unpaid principal	95		95		100
Loans with a specific valuation allowance, recorded balance	97		97		102
Loans with a specific valuation allowance, unpaid principal	97		97		102
Valuation allowance	16		16		15
Loans with a specific valuation allowance, recorded balance	192		192		202
Loans unpaid principal	$ 192		$ 192		$ 202

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=123577603&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=123577603&loc=d3e5258-111524

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