Loans Receivable, Net - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - Beginning Balance	$ 5,140	$ 4,946
Charge-offs	(257)	(78)
Recoveries	138	372
Provision for (recovery of) loan losses	603	(100)
Allowance for loan losses - Ending Balance	5,624	5,140
Allowance for Loan Losses, Collectively Evaluated for Impairment	5,555	4,982
Allowance for Loan Losses, Individually Evaluated for Impairment	69	158
Loans, gross	579,504	483,549
Loans Receivable, Collectively Evaluated for Impairment	568,057	470,681
Loans Receivable, Individually Evaluated for Impairment	11,447	12,868
One-to-four family
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - Beginning Balance	1,058	1,055
Charge-offs	0	0
Recoveries	13	88
Provision for (recovery of) loan losses	(340)	(85)
Allowance for loan losses - Ending Balance	731	1,058
Allowance for Loan Losses, Collectively Evaluated for Impairment	731	1,026
Allowance for Loan Losses, Individually Evaluated for Impairment	0	32
Loans, gross	70,261	78,213
Loans Receivable, Collectively Evaluated for Impairment	65,369	74,387
Loans Receivable, Individually Evaluated for Impairment	4,892	3,826
Multifamily
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - Beginning Balance	880	1,011
Charge-offs	0	0
Recoveries	0	0
Provision for (recovery of) loan losses	234	(131)
Allowance for loan losses - Ending Balance	1,114	880
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,114	880
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Loans, gross	162,261	106,400
Loans Receivable, Collectively Evaluated for Impairment	161,746	106,031
Loans Receivable, Individually Evaluated for Impairment	515	369
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - Beginning Balance	907	812
Charge-offs	0	0
Recoveries	0	0
Provision for (recovery of) loan losses	250	95
Allowance for loan losses - Ending Balance	1,157	907
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,157	907
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Loans, gross	175,313	148,809
Loans Receivable, Collectively Evaluated for Impairment	175,313	147,891
Loans Receivable, Individually Evaluated for Impairment	0	918
Business
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - Beginning Balance	1,855	1,567
Charge-offs	0	(24)
Recoveries	102	278
Provision for (recovery of) loan losses	540	34
Allowance for loan losses - Ending Balance	2,497	1,855
Allowance for Loan Losses, Collectively Evaluated for Impairment	2,428	1,729
Allowance for Loan Losses, Individually Evaluated for Impairment	69	126
Loans, gross	170,031	147,680
Loans Receivable, Collectively Evaluated for Impairment	163,991	139,925
Loans Receivable, Individually Evaluated for Impairment	6,040	7,755
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - Beginning Balance	165	212
Charge-offs	(257)	(54)
Recoveries	23	6
Provision for (recovery of) loan losses	192	1
Allowance for loan losses - Ending Balance	123	165
Allowance for Loan Losses, Collectively Evaluated for Impairment	123	165
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Loans, gross	1,638	2,447
Loans Receivable, Collectively Evaluated for Impairment	1,638	2,447
Loans Receivable, Individually Evaluated for Impairment	0	0
Unallocated
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - Beginning Balance	275	289
Charge-offs	0	0
Recoveries	0	0
Provision for (recovery of) loan losses	(273)	(14)
Allowance for loan losses - Ending Balance	2	275
Allowance for Loan Losses, Collectively Evaluated for Impairment	2	275
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Loans, gross	0	0
Loans Receivable, Collectively Evaluated for Impairment	0	0
Loans Receivable, Individually Evaluated for Impairment	$ 0	$ 0

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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

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Amount of expense related to estimated loss from loan and lease transactions.

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