Accounts Payable and Accrued Expenses - Schedule of Product Warranty Activity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 2,344	$ 3,601
Change in accruals for warranties during the period	890	1,219
Settlements during the period	(1,465)	(2,476)
Balance at end of period	$ 1,769	$ 2,344