Changes in Valuation Allowance for Deferred Tax Assets (Detail) - Valuation Allowance of Deferred Tax Assets - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Valuation Allowance [Line Items]
Balance at beginning of year	$ 15,667	$ 15,170	$ 1,302
Increase	3,738	497	13,868
Balance at end of year	$ 19,405	$ 15,667	$ 15,170