Intangible Assets (Details) (USD $)	12 Months Ended
	Jan. 27, 2013	Jan. 29, 2012	Jan. 30, 2011
Amortizable intangible assets components [Line Items]
Gross Carrying Amount	$ 579,041,000	$ 524,425,000
Accumulated Amortization	(266,709,000)	(198,289,000)
Net Carrying Amount	312,332,000	326,136,000
Amortization expense associated with intangible assets
Amortization expense	68,400,000	59,000,000	30,000,000
Future amortization expense associated with intangible assets
Fiscal 2014	68,400,000
Fiscal 2015	68,300,000
Fiscal 2016	59,700,000
Fiscal 2017	44,100,000
Fiscal 2018	40,500,000
Future amortization after year five	31,300,000
Acquisition-related intangible assets
Amortizable intangible assets components [Line Items]
Gross Carrying Amount	172,039,000	172,039,000
Accumulated Amortization	(96,389,000)	(79,261,000)
Net Carrying Amount	75,650,000	92,778,000
Finite-Lived Intangible Assets, Average Useful Life	6.9	6.0
Patents and Licensed Technology
Amortizable intangible assets components [Line Items]
Gross Carrying Amount	407,002,000	352,386,000
Accumulated Amortization	(170,320,000)	(119,028,000)
Net Carrying Amount	$ 236,682,000	$ 233,358,000
Finite-Lived Intangible Assets, Average Useful Life	7.0	7.3