Note 3 - Loans Receivable - Impaired Loans by Segment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Recorded investment, with no allowance recorded	$ 1,747		$ 1,747		$ 1,833
Unpaid principal balance, with no allowance recorded	2,219		2,219		2,343
Recorded investment, with an allowance recorded	4,608		4,608		4,556
Unpaid principal balance, with an allowance recorded	5,079		5,079		4,929
Related allowance	247		247		202
Recorded investment, total	6,355		6,355		6,389
Unpaid principal balance, total	7,298		7,298		7,272
Average recorded investment, with no allowance recorded	1,903	$ 1,548	1,707	$ 1,665
Interest income recognized, with no allowance recorded	22	44	38	95
Average recorded investment, with an allowance recorded	5,332	4,651	4,977	4,593
Interest income recognized, with an allowance recorded	122	92	203	214
Average recorded investment, total	7,235	6,199	6,684	6,258
Interest income recognized, total	144	136	241	309
Real Estate Portfolio Segment [Member] \| One-to-four Family Loan [Member]
Recorded investment, with no allowance recorded	202		202		297
Unpaid principal balance, with no allowance recorded	229		229		332
Recorded investment, with an allowance recorded	3,809		3,809		2,691
Unpaid principal balance, with an allowance recorded	4,017		4,017		2,911
Related allowance	53		53		31
Recorded investment, total	4,011		4,011		2,988
Unpaid principal balance, total	4,246		4,246		3,243
Average recorded investment, with no allowance recorded	203	236	154	243
Interest income recognized, with no allowance recorded	6	4	6	8
Average recorded investment, with an allowance recorded	4,397	2,891	3,335	2,850
Interest income recognized, with an allowance recorded	91	64	158	146
Average recorded investment, total	4,600	3,127	3,489	3,093
Interest income recognized, total	97	68	164	154
Real Estate Portfolio Segment [Member] \| Multi-family Loan [Member]
Recorded investment, with no allowance recorded	287		287		0
Unpaid principal balance, with no allowance recorded	287		287		0
Recorded investment, with an allowance recorded	0		0		107
Unpaid principal balance, with an allowance recorded	0		0		107
Related allowance	0		0		1
Recorded investment, total	287		287		107
Unpaid principal balance, total	287		287		107
Average recorded investment, with no allowance recorded	294	108	197	109
Interest income recognized, with no allowance recorded	1	1	0	4
Average recorded investment, with an allowance recorded	0	108	158	109
Interest income recognized, with an allowance recorded	0	1	0	4
Average recorded investment, total	294		355
Interest income recognized, total	1		0
Real Estate Portfolio Segment [Member] \| Commercial Real Estate [Member]
Recorded investment, with no allowance recorded	1,221		1,221		1,240
Unpaid principal balance, with no allowance recorded	1,310		1,310		1,320
Recorded investment, with an allowance recorded	66		66		643
Unpaid principal balance, with an allowance recorded	66		66		643
Related allowance	1		1		8
Recorded investment, total	1,287		1,287		1,883
Unpaid principal balance, total	1,376		1,376		1,963
Average recorded investment, with no allowance recorded	1,200	1,260	1,211	1,278
Interest income recognized, with no allowance recorded	1	15	15	39
Average recorded investment, with an allowance recorded	67	651	380	657
Interest income recognized, with an allowance recorded	2	8	2	23
Average recorded investment, total	1,267	1,911	1,591	1,935
Interest income recognized, total	3	23	17	62
Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Recorded investment, with no allowance recorded	0		0		0
Unpaid principal balance, with no allowance recorded	0		0		33
Recorded investment, with an allowance recorded	25		25		29
Unpaid principal balance, with an allowance recorded	57		57		29
Related allowance	1		1		0
Recorded investment, total	25		25		29
Unpaid principal balance, total	57		57		62
Average recorded investment, with no allowance recorded	0	52	12	57
Interest income recognized, with no allowance recorded	0	2	0	2
Average recorded investment, with an allowance recorded	26	52	28	57
Interest income recognized, with an allowance recorded	2	2	3	2
Average recorded investment, total	26		40
Interest income recognized, total	2		3
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member]
Recorded investment, with no allowance recorded	37		37		45
Unpaid principal balance, with no allowance recorded	94		94		110
Recorded investment, with an allowance recorded	100		100		226
Unpaid principal balance, with an allowance recorded	159		159		286
Related allowance	4		4		15
Recorded investment, total	137		137		271
Unpaid principal balance, total	253		253		396
Average recorded investment, with no allowance recorded	38	52	43	144
Interest income recognized, with no allowance recorded	1	14	1	30
Average recorded investment, with an allowance recorded	140	289	212	297
Interest income recognized, with an allowance recorded	3	6	7	14
Average recorded investment, total	178	341	255	441
Interest income recognized, total	4	20	8	44
Consumer Portfolio Segment [Member] \| Automobile and Other Loan [Member]
Recorded investment, with no allowance recorded	0		0		251
Unpaid principal balance, with no allowance recorded	299		299		548
Recorded investment, with an allowance recorded	608		608		597
Unpaid principal balance, with an allowance recorded	780		780		690
Related allowance	188		188		142
Recorded investment, total	608		608		848
Unpaid principal balance, total	1,079		1,079		1,238
Average recorded investment, with no allowance recorded	0	0	0	0
Interest income recognized, with no allowance recorded	13	10	16	14
Average recorded investment, with an allowance recorded	702	394	718	324
Interest income recognized, with an allowance recorded	24	9	33	16
Average recorded investment, total	702	394	718	324
Interest income recognized, total	37	19	49	30
Commercial Portfolio Segment [Member]
Recorded investment, with no allowance recorded	0		0		0
Unpaid principal balance, with no allowance recorded	0		0		0
Recorded investment, with an allowance recorded	0		0		263
Unpaid principal balance, with an allowance recorded	0		0		263
Related allowance	0		0		5
Recorded investment, total	0		0		263
Unpaid principal balance, total	0		0		$ 263
Average recorded investment, with no allowance recorded	168	0	90	0
Interest income recognized, with no allowance recorded	0	1	0	4
Average recorded investment, with an allowance recorded	0	266	146	299
Interest income recognized, with an allowance recorded	0	2	0	9
Average recorded investment, total	168	266	236	299
Interest income recognized, total	$ 0	$ 3	$ 0	$ 13

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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