Inventories - Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Mar. 31, 2014
Inventory Disclosure [Abstract]
Finished goods	$ 841	$ 2,751
Work in process	7,899	5,932
Purchased and manufactured parts	16,683	13,155
Inventories, gross	25,423	21,838
Reserve for slow moving and obsolescence	(2,837)	(2,929)
Total	$ 22,586	$ 18,909