Note 3 - Loans Receivable - Impaired Loans by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Recorded investment, with no allowance recorded	$ 1,764	$ 1,833
Unpaid principal balance, with no allowance recorded	2,196	2,343
Average recorded investment, with no allowance recorded	1,718	1,648
Interest income recognized, with no allowance recorded	60	89
Recorded investment, with an allowance recorded	3,747	4,556
Unpaid principal balance, with an allowance recorded	4,139	4,929
Related allowance	317	202
Average recorded investment, with an allowance recorded	4,660	4,557
Interest income recognized, with an allowance recorded	225	271
Recorded investment, total	5,511	6,389
Unpaid principal balance, total	6,335	7,272
Average recorded investment, total	6,378	6,205
Interest income recognized, total	285	360
Real Estate Portfolio Segment [Member] \| One-to-four Family Loan [Member]
Recorded investment, with no allowance recorded	227	297
Unpaid principal balance, with no allowance recorded	257	332
Average recorded investment, with no allowance recorded	168	237
Interest income recognized, with no allowance recorded	13	11
Recorded investment, with an allowance recorded	2,739	2,691
Unpaid principal balance, with an allowance recorded	2,941	2,911
Related allowance	36	31
Average recorded investment, with an allowance recorded	3,197	2,801
Interest income recognized, with an allowance recorded	177	178
Recorded investment, total	2,966	2,988
Unpaid principal balance, total	3,198	3,243
Average recorded investment, total	3,365	3,038
Interest income recognized, total	190	189
Real Estate Portfolio Segment [Member] \| Multi-family Loan [Member]
Recorded investment, with no allowance recorded	284	107
Unpaid principal balance, with no allowance recorded	284	107
Average recorded investment, with no allowance recorded	219	109
Interest income recognized, with no allowance recorded	0	5
Recorded investment, with an allowance recorded	0	107
Unpaid principal balance, with an allowance recorded	0	107
Related allowance	0	1
Average recorded investment, with an allowance recorded	119	109
Interest income recognized, with an allowance recorded	0	5
Recorded investment, total	284
Unpaid principal balance, total	284
Average recorded investment, total	338
Interest income recognized, total	0
Real Estate Portfolio Segment [Member] \| Commercial Real Estate [Member]
Recorded investment, with no allowance recorded	1,216	1,240
Unpaid principal balance, with no allowance recorded	1,308	1,320
Average recorded investment, with no allowance recorded	1,213	1,271
Interest income recognized, with no allowance recorded	33	54
Recorded investment, with an allowance recorded	62	643
Unpaid principal balance, with an allowance recorded	62	643
Related allowance	1	8
Average recorded investment, with an allowance recorded	301	654
Interest income recognized, with an allowance recorded	3	34
Recorded investment, total	1,278	1,883
Unpaid principal balance, total	1,370	1,963
Average recorded investment, total	1,514	1,925
Interest income recognized, total	36	88
Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Recorded investment, with no allowance recorded	0	0
Unpaid principal balance, with no allowance recorded	29	33
Average recorded investment, with no allowance recorded	9	0
Interest income recognized, with no allowance recorded	0	0
Recorded investment, with an allowance recorded	26	29
Unpaid principal balance, with an allowance recorded	26	29
Related allowance	0	0
Average recorded investment, with an allowance recorded	27	50
Interest income recognized, with an allowance recorded	3	3
Recorded investment, total	26	29
Unpaid principal balance, total	55	62
Average recorded investment, total	36	50
Interest income recognized, total	3	3
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member]
Recorded investment, with no allowance recorded	37	45
Unpaid principal balance, with no allowance recorded	94	110
Average recorded investment, with no allowance recorded	41	120
Interest income recognized, with no allowance recorded	1	2
Recorded investment, with an allowance recorded	98	226
Unpaid principal balance, with an allowance recorded	157	286
Related allowance	4	15
Average recorded investment, with an allowance recorded	186	281
Interest income recognized, with an allowance recorded	9	19
Recorded investment, total	135	271
Unpaid principal balance, total	251	396
Average recorded investment, total	227	401
Interest income recognized, total	10	21
Consumer Portfolio Segment [Member] \| Automobile and Other Loan [Member]
Recorded investment, with no allowance recorded	0	251
Unpaid principal balance, with no allowance recorded	224	548
Average recorded investment, with no allowance recorded	0	20
Interest income recognized, with no allowance recorded	13	18
Recorded investment, with an allowance recorded	822	597
Unpaid principal balance, with an allowance recorded	953	690
Related allowance	276	142
Average recorded investment, with an allowance recorded	721	372
Interest income recognized, with an allowance recorded	33	19
Recorded investment, total	822	848
Unpaid principal balance, total	1,177	1,238
Average recorded investment, total	721	392
Interest income recognized, total	46	37
Commercial Portfolio Segment [Member]
Recorded investment, with no allowance recorded	0	0
Unpaid principal balance, with no allowance recorded	0	0
Average recorded investment, with no allowance recorded	68	0
Interest income recognized, with no allowance recorded	0	4
Recorded investment, with an allowance recorded	0	263
Unpaid principal balance, with an allowance recorded	0	263
Related allowance	0	5
Average recorded investment, with an allowance recorded	109	290
Interest income recognized, with an allowance recorded	0	13
Recorded investment, total	0	263
Unpaid principal balance, total	0	263
Average recorded investment, total	177	290
Interest income recognized, total	$ 0	$ 17

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=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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