Accounts Payable and Accrued Expenses - Schedule of Product Warranty Activity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Payables And Accruals [Abstract]
Balance at beginning of period	$ 2,855	$ 2,787	$ 3,207	$ 2,709
Change in accruals for warranties during the period	974	342	903	493
Settlements during the period	(462)	(60)	(743)	(133)
Balance at end of period	$ 3,367	$ 3,069	$ 3,367	$ 3,069