Past Due Financing Receivables (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 590,534	$ 597,896
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	15,140
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	12,539	211
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,809	7,594
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	23,348	22,945
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	567,186	574,951
One-to-four family
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income	65,526	65,808
One-to-four family | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	1,207
One-to-four family | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	263	185
One-to-four family | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,649	2,475
One-to-four family | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,912	3,867
One-to-four family | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	62,614	61,941
Multifamily
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income	178,815	179,117
Multifamily | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	1,458
Multifamily | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	551	0
Multifamily | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,078	71
Multifamily | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,629	1,529
Multifamily | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	177,186	177,588
Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income	173,088	178,424
Commercial real estate | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	1,370
Commercial real estate | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Commercial real estate | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	4,522	0
Commercial real estate | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	4,522	1,370
Commercial real estate | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	168,566	177,054
Business
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income	163,348	166,908	[1]
Business | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	11,006
Business | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	11,652	0
Business | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,528	5,014
Business | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	14,180	16,020
Business | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	149,168	150,888
Consumer
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income	9,757	7,639	[2]
Consumer | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	99
Consumer | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	73	26
Consumer | Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	32	34
Consumer | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	105	159
Consumer | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 9,652	$ 7,480

[1] (1) Includes PPP loans and business overdrafts

[2] 2) Includes personal loans and consumer overdrafts