Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Mar. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	$ 586,749	$ 579,504
Multifamily
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	177,647	162,261
Multifamily | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	175,990	155,274
Multifamily | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	771	897
Multifamily | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	886	6,090
Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	173,219	175,313
Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	165,237	164,543
Commercial real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	707	8,157
Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	7,275	2,613
Business
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	167,602	170,031
Business | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	154,280	155,196
Business | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	6,136	6,302
Business | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	7,186	8,533
One-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	66,142	70,261
One-to-four family | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	61,045	65,369
One-to-four family | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	5,097	4,892
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	2,139	1,638
Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	2,139	1,613
Consumer | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, gross	$ 0	$ 25