Stock Option And Benefit Plans (Grant Date Fair Value For Awards Estimated Using Option Valuation Method With Weighted Average Assumptions) (Detail) (Number of Options/SARs Outstanding [Member])	0 Months Ended	1 Months Ended		3 Months Ended
	Jul. 25, 2012	Jan. 26, 2012	Jul. 27, 2011	Oct. 21, 2010
Number of Options/SARs Outstanding [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Risk – free interest rate	0.46%	0.52%	1.16%	0.73%
Expected volatility	66.50%	64.90%	65.50%	68.30%
Expected life	4 years	4 years	4 years	3 years 6 months 22 days