Balance Sheet Components (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012	Dec. 31, 2012
Balance Sheet Components [Line Items]
Cost method investment	$ 1,322,000		$ 1,322,000		$ 1,322,000
Cost-method Investments, Other than Temporary Impairment	0	0	0	0
Depreciation	4,400,000	2,900,000	7,800,000	5,500,000
Acquired Indefinite-lived Intangible Asset, Amount	9,500,000		9,500,000
Indefinite-Lived Intangible Assets (Excluding Goodwill)	7,500,000		7,500,000		1,000,000
Amortization expense	5,000,000	1,000,000	6,500,000	2,000,000
Impairment of Intangible Assets (Excluding Goodwill)	0	0	0	0
Goodwill, Acquired During Period			54,525,000
Goodwill, Impairment Loss	0	0	0	0
Minimum [Member]
Balance Sheet Components [Line Items]
Available-for-sale Securities, Maturity Period ( in months)			3 months
Maximum [Member]
Balance Sheet Components [Line Items]
Available-for-sale Securities, Maturity Period ( in months)			12 months
Retail [Member]
Balance Sheet Components [Line Items]
Goodwill, Acquired During Period			0
Commercial [Member]
Balance Sheet Components [Line Items]
Goodwill, Acquired During Period			1,195,000
Service Provider [Member]
Balance Sheet Components [Line Items]
Goodwill, Acquired During Period			53,330,000
Non-Patent [Member]
Balance Sheet Components [Line Items]
Acquired Finite-lived Intangible Asset, Amount	64,200,000		64,200,000
Patents [Member]
Balance Sheet Components [Line Items]
Acquired Finite-lived Intangible Asset, Amount	300,000		300,000
Sierra Wireless AirCard Business [Member] | In-Process Research and Development [Member]
Balance Sheet Components [Line Items]
Future Cost to Complete In-Process Research and Development	7,400,000		7,400,000
In Process Research and Development achieving technological feasibility	$ 2,000,000		$ 2,000,000