Acquisitions - Narrative (Pro forma Information) (Details) (USD $)		12 Months Ended
	Mar. 20, 2012	Jan. 27, 2013 Gennum contingency	Jan. 29, 2012 Gennum
Business Acquisition [Line Items]
Pro forma adjustment, increase (decrease) in cost of goods sold		$ (39,400,000)	$ 41,800,000
Pro forma adjustment, decrease in operating expense			(12,900,000)
Pro forma adjustment, number of pre-acquisition contingencies settled		2
Pro forma adjustment, increase in operating expense due to settlement		4,200,000
Pro forma adjustment, increase (decrease) in amortization expense		(1,600,000)	22,800,000
Pro forma adjustment, increase (decrease) in income tax benefit		(23,400,000)	23,400,000
Pro forma adjustment, increase in interest expense		1,700,000	16,600,000
Debt instrument, face amount	$ 350,000,000