Mortgage Servicing - Summary of Activity in Mortgage Servicing Rights Using Amortized Cost (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2023	Mar. 31, 2023
Transfers and Servicing [Abstract]
Balance at beginning of year	$ 434	$ 563
Additions	103	33
Repayments and amortization	(113)	(162)
Balance at end of period	$ 424	$ 434