Accounts Payable and Accrued Expenses - Schedule of Accounts Payable and Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013
Accounts payable	$ 5,178	$ 7,146
Accrued miscellaneous expenses	6,024	9,142
Accrued outside services	4,167	2,251
Accrued subcontractor program costs	290	2,442
Accrued compensation	4,369	6,315
Income taxes payable	148	133
Accrued warranty	3,327	2,709
Total	$ 23,503	$ 30,138