Income Taxes - Liability For Uncertain Tax Positions (Details) (USD $) In Thousands, unless otherwise specified	Apr. 26, 2015	Jan. 25, 2015
Income Tax Contingency [Line Items]
Total accrued taxes	$ 7,643	$ 7,774
Non-current deferred tax asset [Member]
Income Tax Contingency [Line Items]
Other long-term liabilities	7,643	7,522
Other liabilities [Member]
Income Tax Contingency [Line Items]
Other long-term liabilities	$ 0	$ 252