Leases - Summary of Components of Lease Costs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lease cost
Operating lease cost	$ 255	$ 254
Total lease cost	255	254
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 266	264
Financing cash flows from finance leases		1
Right-of-use assets obtained in exchange for lease obligations:
Operating leases		650
Finance leases		$ 5