Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Mar. 31, 2022
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired Financing Receivable, Recorded Investment	$ 18,410		$ 18,410		$ 11,447
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired Financing Receivable, Unpaid Principal Balance	19,174		19,174		12,203
Impaired Financing Receivable, Related Allowance	255		255		69
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired Financing Receivable, Average Recorded Investment	19,775	$ 12,807	14,929	$ 13,055
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Impaired Financing Receivable, Interest Income, Cash Basis Method	121	53	424	209
One-to-four family
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	4,066		4,066		4,892
Impaired Financing Receivable, with Related Allowance, Recorded Investment	1,031		1,031		0
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	4,661		4,661		5,576
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	1,031		1,031		0
Impaired Financing Receivable, Related Allowance	103		103		0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	4,204	4,429	4,479	4,443
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,035	73	516	74
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	2	13	40	19
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	9	0	31	1
Multifamily
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	71		71		515
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	71		71		515
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	36	699	293	442
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	9	0	9
Commercial real estate
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	7,275		7,275		0
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	7,401		7,401		0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	7,560	188	3,637	551
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	804
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	33	7	107	7
Business
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,168		1,168		837
Impaired Financing Receivable, with Related Allowance, Recorded Investment	4,799		4,799		5,203
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,211		1,211		909
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	4,799		4,799		5,203
Impaired Financing Receivable, Related Allowance	152		152		$ 69
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,174	2,125	1,003	2,212
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	4,962	5,293	5,001	5,333
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	10	24	44	24
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	$ 67	$ 0	$ 202	$ 149