Income Taxes - Narrative (Details) (USD $)	12 Months Ended
	Jan. 26, 2014	Jan. 27, 2013
Income Tax [Line Items]
Net operating loss carryforward deferred tax asset attributed to excess equity deductions	$ 8,000,000
Unremitted earnings related to foreign subsidiaries	496,800,000
Percentage of uncertain tax positions evaluating criteria	50.00%
Net tax benefits, if recognized, would impact the effective tax rate	12,300,000	11,100,000
Unrecognized tax benefits, interest and penalties	293,000	293,000
Reasonably possible decrease in unrecognized tax benefits within twelve months	3,800,000
Internal Revenue Service (IRS)
Income Tax [Line Items]
Operating loss carryforwards	81,600,000
Research credits available to offset taxable income	12,700,000
Alternative minimum tax credits available	1,300,000
Canada Tax Authority
Income Tax [Line Items]
Research credits available to offset taxable income	40,900,000
State and local jurisdiction
Income Tax [Line Items]
Operating loss carryforwards	95,600,000
Research credits available to offset taxable income	13,100,000
United States
Income Tax [Line Items]
Increase in valuation allowance reserve	44,000,000
Canada
Income Tax [Line Items]
Increase in valuation allowance reserve	$ 8,400,000