Inventories - Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015
Inventory Disclosure [Abstract]
Finished goods	$ 1,049	$ 1,040
Work in process	9,933	7,515
Purchased and manufactured parts	17,456	13,418
Inventories, gross	28,438	21,973
Reserve for slow moving and obsolescence	(2,656)	(2,546)
Total	$ 25,782	$ 19,427