Property, Plant and Equipment - Summary of property, plant and equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2015		Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	$ 25,619		$ 24,284
Less accumulated depreciation and amortization	(15,411)		(14,909)
Total property, plant and equipment	10,208	[1]	9,375
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	21		21
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	10,326		7,916
Less accumulated depreciation and amortization	(2,907)		(2,811)
Machinery, equipment and tooling
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	14,664		13,530
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	$ 608		$ 2,817

[1] (Unaudited)