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Loans and Allowance for Credit Losses- Additional Information (Detail)	9 Months Ended	12 Months Ended
	Mar. 31, 2023 USD ($) SecurityLoan Loans	Jun. 30, 2022 USD ($) SecurityLoan Loans	Mar. 31, 2022 USD ($) Loans
Loans and Allowance for Credit Losses [Line Items]
Maximum term of fixed-rate one- to four-family residential mortgage loans	15 years
Number of default loans | SecurityLoan	0	0
Investment recorded prior to modification	$ 0	$ 0
Loans and Leases Receivable, Gross	585,814,000	525,736,000	$ 505,712,000
Allowance for Loan and Lease Losses, Loans Acquired	143,000
Fair Value, Concentration of Risk, Collateral Policy [Member]
Loans and Allowance for Credit Losses [Line Items]
Commercial and multi-family real estate	$ 334,513,000	290,972,000
Troubled Debt Restructurings [Member]
Loans and Allowance for Credit Losses [Line Items]
Minimum period for default	90 days
Commercial Business Loans [Member]
Loans and Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross	$ 71,129,000	$ 80,418,000	$ 81,399,000
Allowance for Loan and Lease Losses, Loans Acquired	$ 143,000
Commercial Business Loans [Member] | Small Business Administration Paycheck Protection Programme Loans [Member]
Loans and Allowance for Credit Losses [Line Items]
Percentage of government guarantee for loans as per scheme	100.00%
Commercial Portfolio And Commercial Residential Portfolio [Member]
Loans and Allowance for Credit Losses [Line Items]
Number of loans as on closing date | Loans	0	0	18
Loans and Leases Receivable, Gross			$ 1,200,000
One- to four-family [Member]
Loans and Allowance for Credit Losses [Line Items]
Loans held for sale	$ 0	$ 227,000
Maximum term of fixed-rate one- to four-family residential mortgage loans	15 years
Loans and Leases Receivable, Gross	$ 158,388,000	132,474,000	$ 124,590,000
Allowance for Loan and Lease Losses, Loans Acquired	0
Purchased Loans and Loan Participations [Member]
Loans and Allowance for Credit Losses [Line Items]
Approximate amount of purchase loans included in loans receivable	675,000	1,570,000
Approximate amount of loans included on out-of-area participation	41,857,000	29,972,000
Amount within 100 miles of primary area	$ 23,646,000	$ 13,234,000
Non troubled debt restructuring [Member] | Covid Nineteen [Member] | Financing receivables, 30 to 59 days past due [Member]
Loans and Allowance for Credit Losses [Line Items]
Financing receivable number of days past due	30 days
Period of loan excecution	60 days

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Number of loans as on closing date.

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Percentage of government guarantee for loans as per scheme.

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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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Amount, after valuation allowance, of financing receivable held for sale and not part of disposal group. Excludes loan covered under loss sharing agreement and loan classified as investment in debt security.

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