Loans Receivable and ALLL (Details) - USD ($) $ in Thousands		Dec. 31, 2022	Sep. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Mar. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, before Fees, Gross		$ 584,066		$ 576,487
Unamortized premiums, deferred costs and fees, net		2,683		3,017
Allowance for loan and lease losses		(5,154)	$ (5,509)	(5,624)	$ (5,488)	$ (5,515)	$ (5,140)
Total loans receivable, net		$ 581,595		$ 573,880
Percentage of Loan Type		100.00%		100.00%
One-to-four family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, before Fees, Gross		$ 65,291		$ 69,297
Allowance for loan and lease losses		$ (724)	(704)	$ (731)	(921)	(1,015)	(1,058)
Percentage of Loan Type		11.20%		12.00%
Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, before Fees, Gross		$ 176,480		$ 160,800
Allowance for loan and lease losses		$ (1,080)	(1,055)	$ (1,114)	(1,102)	(914)	(880)
Percentage of Loan Type		30.20%		27.90%
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, before Fees, Gross		$ 172,468		$ 174,270
Allowance for loan and lease losses		$ (1,045)	(1,608)	$ (1,157)	(1,095)	(1,002)	(907)
Percentage of Loan Type		29.50%		30.20%
Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, before Fees, Gross	[1]	$ 167,700		$ 170,497
Allowance for loan and lease losses		$ (1,913)	(1,814)	$ (2,497)	(2,108)	(2,106)	(1,855)
Percentage of Loan Type	[1]	28.70%		29.60%
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, before Fees, Gross	[2]	$ 2,127		$ 1,623
Allowance for loan and lease losses		$ (121)	$ (82)	$ (123)	$ (131)	$ (137)	$ (165)
Percentage of Loan Type	[2]	0.40%		0.30%

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

[2] 2) Includes personal loans and consumer overdrafts