Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 49,454		$ 49,040
Accumulated depreciation	(40,784)		(40,541)
Total property, plant and equipment, net	8,670		8,499
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,850		2,869
Leasehold improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Leasehold improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	20 years
Computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	35,519		35,554
Computer equipment | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	3 years
Computer equipment | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	5,755		5,648
Machinery and equipment | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	3 years
Machinery and equipment | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	700		688
Estimated Useful Life (in years)	5 years
Work in Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 4,630	[1]	$ 4,281	[1]

[1] Work in progress includes internal use software development and production tooling construction in progress.