Intangible Assets (Details) (USD $)	3 Months Ended		6 Months Ended
	Jul. 29, 2012	Jul. 31, 2011	Jul. 29, 2012	Jul. 31, 2011	Jan. 29, 2012
Amortizable intangible assets components
Gross Carrying Amount	$ 578,993,000		$ 578,993,000		$ 524,425,000
Accumulated Amortization	(232,055,000)		(232,055,000)		(198,289,000)
Net Carrying Amount	346,938,000		346,938,000		326,136,000
Amortization expense associated with intangible assets
Amortization expense	17,200,000	15,600,000	33,800,000	26,500,000
Future amortization expense associated with intangible assets
Remainder of fiscal 2013			34,400,000
Fiscal 2014			66,500,000
Fiscal 2015			66,400,000
Fiscal 2016			60,900,000
Fiscal 2017			50,400,000
Fiscal 2018 and fiscal years subsequent of fiscal 2018			68,300,000
Acquisition-related intangible assets
Amortizable intangible assets components
Gross Carrying Amount	172,039,000		172,039,000		172,039,000
Accumulated Amortization	(87,659,000)		(87,659,000)		(79,261,000)
Net Carrying Amount	84,380,000		84,380,000		92,778,000
Patents and Licensed Technology [Member]
Amortizable intangible assets components
Gross Carrying Amount	406,954,000		406,954,000		352,386,000
Accumulated Amortization	(144,396,000)		(144,396,000)		(119,028,000)
Net Carrying Amount	$ 262,558,000		$ 262,558,000		$ 233,358,000