Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment at cost	$ 3,857		$ 3,857		$ 3,494
Less: accumulated depreciation	(3,125)		(3,125)		(3,015)
Property and equipment, net	732		732		479
Depreciation	55	$ 57	107	$ 114
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment at cost	1,608		$ 1,608		$ 1,495
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life			3 years		3 years
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life			15 years		15 years
Tooling [Member]
Property, Plant and Equipment [Line Items]
Property and equipment at cost	865		$ 865		$ 865
Tooling [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life			2 years		2 years
Tooling [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life			5 years		5 years
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment at cost	102		$ 102		$ 92
Useful life			5 years		5 years
Computer software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment at cost	452		$ 452		$ 452
Useful life			3 years		3 years
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment at cost	573		$ 573		$ 572
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment at cost	$ 257		$ 257		$ 18