Significant Accounting Policies - Narrative (Details) (USD $)	3 Months Ended	12 Months Ended
	Oct. 28, 2012	Jan. 25, 2015	Jan. 26, 2014	Jan. 27, 2013
Other Intangible Assets and Long-lived Assets [Abstract]
Percent of realizable undiscounted cash flows used to determine useful life of acquired finite-lived intangible assets, minimum		90.00%
Licensing Revenue [Abstract]
License revenue from a single licensing arrangement	$ 7,500,000
Sales and Marketing [Abstract]
Advertising Expense		52,000	118,000	119,000
Product Development and Engineering [Abstract]
Recoveries from nonrecurring engineering services		$ 29,300,000	$ 17,600,000	$ 12,500,000
Maximum
Investment maturity period		90 days