Goodwill and Purchased Intangible Assets (Details) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			1 Months Ended
	Sep. 29, 2012	Sep. 24, 2011	Sep. 29, 2012	Sep. 24, 2011	Dec. 31, 2011	Aug. 17, 2012 Duma technology [Member]
Intangible Assets [Line Items]
Purchase price of the assets acquired						$ 1.0
Amortization period of intangible assets						3 years
Maximum future payments required						0.5
Amortization expenses related to intangible assets	1.0	1.1	3.0	3.6
Unamortized Trade Name	$ 2.2		$ 2.2		$ 2.2