Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,572	$ 1,547
Less: Accumulated depreciation	(614)	(503)
Property And Equipment, net	958	1,044
Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	500	500
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	88	88
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	72	72
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	74	62
Research equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	680	667
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 158	$ 158