Intangible Assets (Details) (USD $)	3 Months Ended
	Apr. 28, 2013	Apr. 29, 2012	Jan. 27, 2013
Amortizable intangible assets components
Gross Carrying Amount	$ 620,873,000		$ 579,041,000
Accumulated Amortization	(284,140,000)		(266,709,000)
Net Carrying Amount	336,733,000		312,332,000
Amortization expense associated with intangible assets
Amortization expense	17,400,000	16,600,000
Future amortization expense associated with intangible assets
Remainder of fiscal 2014	56,600,000
Fiscal 2015	75,300,000
Fiscal 2016	68,200,000
Fiscal 2017	51,700,000
Fiscal 2018	48,700,000
Fiscal 2019 and fiscal years subsequent of fiscal 2019	36,200,000
Acquisition-related intangible assets
Amortizable intangible assets components
Gross Carrying Amount	172,039,000		172,039,000
Accumulated Amortization	(100,306,000)		(96,389,000)
Net Carrying Amount	71,733,000		75,650,000
Patents and Licensed Technology [Member]
Amortizable intangible assets components
Gross Carrying Amount	448,834,000		407,002,000
Accumulated Amortization	(183,834,000)		(170,320,000)
Net Carrying Amount	$ 265,000,000		$ 236,682,000