Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses - Beginning Balance	$ 5,515	$ 4,916	$ 5,140	$ 4,946
Charge-offs	(252)	(57)	(223)	(76)
Recoveries	33	275	103	367
Provision for loan losses	192	4	468	(99)
Allowance for loan losses - Ending Balance	5,488	5,138	5,488	5,138
Allowance for Loan Losses, Collectively Evaluated for Impairment	5,376		5,376		$ 4,982
Allowance for Loan Losses, Individually Evaluated for Impairment	112		112		158
Loans, gross	552,877		552,877		483,549
Loans Receivable, Collectively Evaluated for Impairment	539,632		539,632		470,681
Loans Receivable, Individually Evaluated for Impairment	13,245		13,245		12,868
One-to-four family
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses - Beginning Balance	1,015	953	1,058	1,055
Charge-offs	0	0	0	0
Recoveries	0	1	0	88
Provision for loan losses	(94)	(90)	(137)	(279)
Allowance for loan losses - Ending Balance	921	864	921	864
Allowance for Loan Losses, Collectively Evaluated for Impairment	892		892		1,026
Allowance for Loan Losses, Individually Evaluated for Impairment	29		29		32
Loans, gross	72,375		72,375		78,213
Loans Receivable, Collectively Evaluated for Impairment	67,165		67,165		74,387
Loans Receivable, Individually Evaluated for Impairment	5,210		5,210		3,826
Multifamily
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses - Beginning Balance	914	960	880	1,011
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision for loan losses	188	67	222	16
Allowance for loan losses - Ending Balance	1,102	1,027	1,102	1,027
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,102		1,102		880
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0		0
Loans, gross	154,230		154,230		106,400
Loans Receivable, Collectively Evaluated for Impairment	153,714		153,714		106,031
Loans Receivable, Individually Evaluated for Impairment	516		516		369
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses - Beginning Balance	1,002	969	907	812
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision for loan losses	93	(3)	188	154
Allowance for loan losses - Ending Balance	1,095	966	1,095	966
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,095		1,095		907
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0		0
Loans, gross	166,050		166,050		148,809
Loans Receivable, Collectively Evaluated for Impairment	165,865		165,865		147,891
Loans Receivable, Individually Evaluated for Impairment	185		185		918
Business
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses - Beginning Balance	2,106	1,636	1,855	1,567
Charge-offs	0	(5)	0	(24)
Recoveries	32	273	82	275
Provision for loan losses	(30)	(66)	171	20
Allowance for loan losses - Ending Balance	2,108	1,838	2,108	1,838
Allowance for Loan Losses, Collectively Evaluated for Impairment	2,025		2,025		1,729
Allowance for Loan Losses, Individually Evaluated for Impairment	83		83		126
Loans, gross	158,487		158,487		147,680
Loans Receivable, Collectively Evaluated for Impairment	151,153		151,153		139,925
Loans Receivable, Individually Evaluated for Impairment	7,334		7,334		7,755
Consumer
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses - Beginning Balance	137	189	165	212
Charge-offs	(123)	(52)	(222)	(52)
Recoveries	1	1	21	4
Provision for loan losses	116	52	167	26
Allowance for loan losses - Ending Balance	131	190	131	190
Allowance for Loan Losses, Collectively Evaluated for Impairment	131		131		165
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0		0
Loans, gross	1,735		1,735		2,447
Loans Receivable, Collectively Evaluated for Impairment	1,735		1,735		2,447
Loans Receivable, Individually Evaluated for Impairment	0		0		0
Unallocated
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses - Beginning Balance	341	209	275	289
Charge-offs	(129)	0	(1)	0
Recoveries	0	0	0	0
Provision for loan losses	(81)	44	(143)	(36)
Allowance for loan losses - Ending Balance	131	$ 253	131	$ 253
Allowance for Loan Losses, Collectively Evaluated for Impairment	131		131		275
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0		0
Loans, gross	0		0		0
Loans Receivable, Collectively Evaluated for Impairment	0		0		0
Loans Receivable, Individually Evaluated for Impairment	$ 0		$ 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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The balance of financing receivables that were individually 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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