Restructuring Costs - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Jan. 31, 2016	Jan. 25, 2015	Jan. 26, 2014
Restructuring Cost and Reserve [Line Items]
Contract commitment cancellation charges	$ 0	$ 2,983	$ 4,926
Inventory write-downs	0	0	15,047
Cost of sales
Restructuring Cost and Reserve [Line Items]
Contract commitment cancellation charges	0	2,983	1,729
Product development and engineering
Restructuring Cost and Reserve [Line Items]
Contract commitment cancellation charges	$ 0	$ 0	$ 3,197

Charge to cost of goods sold that represents the reduction of the carrying amount of inventory, generally attributable to obsolescence or market conditions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=28360613&loc=d3e4542-108314

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Name:	us-gaap_InventoryWriteDown
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration