Income Taxes - Summary of Changes in the Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
Jan. 31, 2016	Jan. 25, 2015	Jan. 26, 2014
Income Tax Disclosure [Abstract]
Beginning balance	$ 75,536	$ 61,251	$ 8,320
Additions	9,055	14,285	52,931
Releases	(7,208)	0	0
Ending balance	$ 77,383	$ 75,536	$ 61,251

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

Name:	us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant