Note 3 - Loans Receivable - Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Allowance at end of period	$ 17,271	$ 16,905	$ 15,778	$ 17,410	$ 17,782	$ 18,823
Loans receivable	1,276,560		1,205,785
Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	11,445
Pooled Loans [Member]
Allowance at end of period	17,271
Loans receivable	1,265,115
Residential Portfolio Segment [Member] | One to Four Family [Member]
Allowance at end of period	4,629	4,415	3,963	4,025	4,596	5,459
Loans receivable	312,657		300,523
Residential Portfolio Segment [Member] | One to Four Family [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	5,870
Residential Portfolio Segment [Member] | One to Four Family [Member] | Pooled Loans [Member]
Allowance at end of period	4,629
Loans receivable	306,787
Residential Portfolio Segment [Member] | Multifamily [Member]
Allowance at end of period	7,391	6,562	5,398	6,028	6,044	5,600
Loans receivable	597,304		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	7,391
Loans receivable	597,304
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Allowance at end of period	163	185	89	156	183	194
Loans receivable	10,552		11,012
Residential Portfolio Segment [Member] | Home Equity Loan [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	45
Residential Portfolio Segment [Member] | Home Equity Loan [Member] | Pooled Loans [Member]
Allowance at end of period	163
Loans receivable	10,507
Construction and Land Portfolio Segment [Member]
Allowance at end of period	1,690	1,831	1,386	1,319	1,251	1,755
Loans receivable	70,075		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	1,690
Loans receivable	70,075
Commercial Real Estate Portfolio Segment [Member]
Allowance at end of period	3,160	3,631	4,482	5,184	5,017	5,138
Loans receivable	266,375		250,676
Commercial Real Estate Portfolio Segment [Member] | Collateral Dependent Loans [Member]
Allowance at end of period	0
Loans receivable	5,530
Commercial Real Estate Portfolio Segment [Member] | Pooled Loans [Member]
Allowance at end of period	3,160
Loans receivable	260,845
Consumer Portfolio Segment [Member]
Allowance at end of period	42	41	33	34	33	35
Loans receivable	740		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	42
Loans receivable	740
Commercial Portfolio Segment [Member]
Allowance at end of period	196	$ 240	427	$ 664	$ 658	$ 642
Loans receivable	18,857		$ 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	196
Loans receivable	$ 18,857