Balance Sheet Components (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 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	4,900,000	3,200,000	12,700,000	8,700,000
Acquired Indefinite-lived Intangible Asset, Amount			9,500,000
Indefinite-Lived Intangible Assets (Excluding Goodwill)	100,000		100,000		1,000,000
Amortization expense	4,500,000	1,400,000	11,000,000	3,400,000
Goodwill, Acquired During Period			55,036,000
Goodwill, Impairment Loss	0	0	0	0
Impairment charges	2,000,000	0	2,000,000	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			53,841,000
Non-Patent [Member]
Balance Sheet Components [Line Items]
Acquired Finite-lived Intangible Asset, Amount			64,200,000
Patents [Member]
Balance Sheet Components [Line Items]
Acquired Finite-lived Intangible Asset, Amount			300,000
Sierra Wireless AirCard Business [Member]
Balance Sheet Components [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	100,000		100,000
Goodwill, Purchase Accounting Adjustments			500,000
Impairment charges			2,000,000
Sierra Wireless AirCard Business [Member] | In-Process Research and Development [Member]
Balance Sheet Components [Line Items]
In Process Research and Development achieving technological feasibility	7,400,000		7,400,000
Future Cost to Complete In-Process Research and Development	$ 400,000		$ 400,000