Accounts Payable and Accrued Expenses - Schedule of Accounts Payable and Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014
Accounts payable	$ 2,554	$ 1,749
Accrued inventories in-transit	1,509	212
Accrued miscellaneous expenses	4,801	6,076
Accrued outside services	3,272	3,716
Accrued subcontractor program costs	288	290
Accrued compensation	3,155	5,939
Income taxes payable	200	173
Accrued adverse purchase commitments	403	402
Accrued warranty	2,855	3,207
Total	$ 19,037	$ 21,764