Stock-Based Compensation - Allocation of Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 26, 2015	Jul. 27, 2014	Jul. 26, 2015	Jul. 27, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 2,335	$ 6,275	$ 8,281	$ 13,122
Inventories [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Net change in stock-based compensation capitalized into inventory	204	37	279	28
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	400	355	875	718
Selling, General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	(141)	3,448	3,073	7,513
Product Development And Engineering [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 2,076	$ 2,472	$ 4,333	$ 4,891