Note 6 - Loans Receivable, Net and Allowance for Loan Losses - Changes in the Allowance for Loan Losses and Recorded Investment in Loans Receivable (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Allowance for loan losses, beginning balance	$ 5,262	$ 3,061	$ 3,061
Charge-offs	0	0	(17)
Recoveries	0	0	17
Provision	679	254	2,201
Allowance for loan losses, ending balance	5,941	3,315	5,262
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	5,941	3,315	5,262
Loans receivable, ending balance	445,083		411,866
Loans receivable, individually evaluated for impairment	1,863
Loans receivable, collectively evaluated for impairment	443,220		411,726
Commercial and Consumer Portfolio Segments [Member]
Loans receivable, collectively evaluated for impairment			129,620
Real Estate Portfolio Segment [Member]
Loans receivable, ending balance	311,644		282,246
Real Estate Portfolio Segment [Member] \| One-to-four Family Residential Owner Occupied Loans [Member]
Allowance for loan losses, beginning balance	73	88	88
Charge-offs	0	0
Recoveries	0	0
Provision	26	19	(15)
Allowance for loan losses, ending balance	99	107	73
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	99	107	73
Loans receivable, ending balance	12,319		9,779
Loans receivable, individually evaluated for impairment	0		0
Loans receivable, collectively evaluated for impairment	12,319		9,779
Real Estate Portfolio Segment [Member] \| One-to-four Family Residential Non-owner Occupied Loans [Member]
Allowance for loan losses, beginning balance	292	362	362
Charge-offs	0	0
Recoveries	0	0
Provision	13	14	(70)
Allowance for loan losses, ending balance	305	376	292
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	305	376	292
Loans receivable, ending balance	38,035		38,752
Loans receivable, individually evaluated for impairment	9		9
Loans receivable, collectively evaluated for impairment	38,026		38,743
Real Estate Portfolio Segment [Member] \| Multi-family (Five Or More) Residential Loans [Member]
Allowance for loan losses, beginning balance	249	229	229
Charge-offs	0	0
Recoveries	0	0
Provision	215	3	20
Allowance for loan losses, ending balance	464	232	249
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	464	232	249
Loans receivable, ending balance	41,331		29,344
Loans receivable, individually evaluated for impairment	1,723		0
Loans receivable, collectively evaluated for impairment	39,608		29,344
Real Estate Portfolio Segment [Member] \| Commercial Real Estate and Lines of Credit [Member]
Allowance for loan losses, beginning balance	2,475	1,287	1,287
Charge-offs	0	0
Recoveries	0	0
Provision	162	92	1,188
Allowance for loan losses, ending balance	2,637	1,379	2,475
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	2,637	1,379	2,475
Loans receivable, ending balance	197,761		183,822
Loans receivable, individually evaluated for impairment	131		131
Loans receivable, collectively evaluated for impairment	197,630		183,691
Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Allowance for loan losses, beginning balance	119	62	62
Charge-offs	0	0
Recoveries	0	0
Provision	13	(5)	57
Allowance for loan losses, ending balance	132	57	119
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	132	57	119
Loans receivable, ending balance	17,617		15,843
Loans receivable, individually evaluated for impairment	0		0
Loans receivable, collectively evaluated for impairment	17,617		15,843
Real Estate Portfolio Segment [Member] \| Home Equity Loan [Member]
Allowance for loan losses, beginning balance	29	20	20
Charge-offs	0	0
Recoveries	0	0
Provision	(1)	7	9
Allowance for loan losses, ending balance	28	27	29
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	28	27	29
Loans receivable, ending balance	4,581		4,706
Loans receivable, individually evaluated for impairment	0		0
Loans receivable, collectively evaluated for impairment	4,581		4,706
Commercial and Consumer Portfolio Segments [Member]
Allowance for loan losses, beginning balance	1,625	763	763
Charge-offs		0	(17)
Recoveries	0	0	17
Provision	251	124	862
Allowance for loan losses, ending balance	1,876	887	1,625
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	1,876	887	1,625
Loans receivable, ending balance	133,439		129,620
Loans receivable, individually evaluated for impairment	0		0
Loans receivable, collectively evaluated for impairment	133,439
Unallocated Financing Receivables [Member]
Allowance for loan losses, beginning balance	400	250	250
Charge-offs	0	0
Recoveries	0	0
Provision	0	0	150
Allowance for loan losses, ending balance	400	250	400
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	$ 400	$ 250	400
Loans receivable, ending balance			411,866
Loans receivable, individually evaluated for impairment			$ 140

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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