Stock-Based Compensation - Allocation of Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 26, 2015	Jul. 31, 2016	Jul. 26, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 6,097	$ 2,335	$ 11,804	$ 8,281
Inventories [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Net change in stock-based compensation capitalized into inventory	(13)	204	(18)	279
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	372	400	749	875
Selling, General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	4,183	(141)	8,036	3,073
Product Development And Engineering [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 1,542	$ 2,076	$ 3,019	$ 4,333