Pension Plans - Reconciliation of Benefit Obligations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Pension benefit obligation, beginning of year	$ 18,789	$ 17,784
Service cost	2,447	1,828	$ 1,574
Contributions paid by plan participants	2,704	2,180
Interest cost	126	131	153
Benefits paid	(2,207)	(2,841)
Prior service cost		836
Actuarial loss / (gain)	473	(1,740)
Foreign currency translation	316	611
Pension benefit obligation, end of year	$ 22,648	$ 18,789	$ 17,784