Note 3 - Loans Receivable - Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Allowance at end of period	$ 17,452	$ 17,271	$ 15,778	$ 16,790	$ 17,410	$ 18,823
Loans receivable	1,354,465		1,205,785
Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	8,813
Pooled Loans [Member]
Allowance at end of period	17,452
Loans receivable	1,345,652
Residential Portfolio Segment [Member] | One to Four Family [Member]
Allowance at end of period	4,496	4,629	3,963	3,924	4,025	5,459
Loans receivable	361,943		300,523
Residential Portfolio Segment [Member] | One to Four Family [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	3,297
Residential Portfolio Segment [Member] | One to Four Family [Member] | Pooled Loans [Member]
Allowance at end of period	4,496
Loans receivable	358,646
Residential Portfolio Segment [Member] | Multifamily [Member]
Allowance at end of period	7,563	7,391	5,398	6,336	6,028	5,600
Loans receivable	621,560		537,956
Residential Portfolio Segment [Member] | Multifamily [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	0
Residential Portfolio Segment [Member] | Multifamily [Member] | Pooled Loans [Member]
Allowance at end of period	7,563
Loans receivable	621,560
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Allowance at end of period	190	163	89	101	156	194
Loans receivable	11,020		11,012
Residential Portfolio Segment [Member] | Home Equity Loan [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	23
Residential Portfolio Segment [Member] | Home Equity Loan [Member] | Pooled Loans [Member]
Allowance at end of period	190
Loans receivable	10,997
Construction and Land Portfolio Segment [Member]
Allowance at end of period	1,511	1,690	1,386	1,283	1,319	1,755
Loans receivable	61,125		82,588
Construction and Land Portfolio Segment [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	0
Construction and Land Portfolio Segment [Member] | Pooled Loans [Member]
Allowance at end of period	1,511
Loans receivable	61,125
Commercial Real Estate Portfolio Segment [Member]
Allowance at end of period	3,437	3,160	4,482	4,685	5,184	5,138
Loans receivable	278,864		250,676
Commercial Real Estate Portfolio Segment [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	5,493
Commercial Real Estate Portfolio Segment [Member] | Pooled Loans [Member]
Allowance at end of period	3,437
Loans receivable	273,371
Consumer Portfolio Segment [Member]
Allowance at end of period	47	42	33	34	34	35
Loans receivable	757		732
Consumer Portfolio Segment [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	0
Consumer Portfolio Segment [Member] | Pooled Loans [Member]
Allowance at end of period	47
Loans receivable	757
Commercial Portfolio Segment [Member]
Allowance at end of period	208	$ 196	427	$ 427	$ 664	$ 642
Loans receivable	19,196		$ 22,298
Commercial Portfolio Segment [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	0
Commercial Portfolio Segment [Member] | Pooled Loans [Member]
Allowance at end of period	208
Loans receivable	$ 19,196