Restructuring Costs - Other Charges in Addition to Restructuring Costs (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jan. 26, 2014	Oct. 27, 2013	Jul. 28, 2013	Apr. 28, 2013	Jan. 27, 2013	Oct. 28, 2012	Jul. 29, 2012	Apr. 29, 2012	Jan. 26, 2014	Jan. 27, 2013	Jan. 29, 2012
Inventory write-downs	$ 15,047	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 15,047	$ 0	$ 0
Long-lived asset impairments	9,196
Contract commitments	4,926
Other charges in addition to restructuring, excluding goodwill and intangible impairments	29,169
Cost of sales
Long-lived asset impairments	4,341
Contract commitments	1,729
Other charges in addition to restructuring, excluding goodwill and intangible impairments	21,117
Selling, general and administrative expenses
Inventory write-downs	0
Long-lived asset impairments	314
Contract commitments	0
Other charges in addition to restructuring, excluding goodwill and intangible impairments	314
Product development and engineering
Inventory write-downs	0
Long-lived asset impairments	4,541
Contract commitments	3,197
Other charges in addition to restructuring, excluding goodwill and intangible impairments	$ 7,738