Other Current Liabilities - Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015
Other Liabilities Disclosure [Abstract]
Engineering project reserves	$ 1,753	$ 1,688
Environmental reserves	2,520	2,387
Accrued medical benefits cost	400	389
Accrued commissions	657	560
Other	719	914
Total	$ 6,049	$ 5,938