Components of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Property, Plant and Equipment [Line Items]
Machinery and equipment	$ 16,805	$ 14,392
Furniture and fixtures	960	969
Leasehold improvements	1,876	1,843
Construction in progress	1,226	1,541
Total cost	20,867	18,745
Less accumulated depreciation	(13,978)	(12,196)
Property and equipment, net	$ 6,889	$ 6,549