Financial Statement Details - Summary of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 72,235	$ 74,931
Less-accumulated depreciation and amortization	(62,334)	(59,702)
Property and equipment, Net	9,901	15,229
Test equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	52,108	53,368
Computer equipment and purchased software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	10,814	12,310
Product tooling [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	3,204	2,232
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	2,015	2,219
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 4,094	$ 4,802