Defined Benefit Pension Plans - Schedule of Net Pension Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Pension And Other Postretirement Plans Disclosure [Abstract]
Employer service cost	$ 456	$ 388	$ 1,362	$ 1,183
Interest cost	31	38	93	115
Expected return on plan assets	(32)	(32)	(94)	(98)
Amortization of prior service credit	(6)	(4)	(17)	(11)
Amortization of net loss	54	38	161	116
Net pension cost	$ 503	$ 428	$ 1,505	$ 1,305