v2.4.0.6
Total Unrecognized Compensation and Weighted-average Years Expected to be Recognized (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Jul. 28, 2012
Year
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost $ 23.8
Weighted-average years expected to be recognized over (years) 2.4
Service-based Restricted Equity Awards
 
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost 12.6
Weighted-average years expected to be recognized over (years) 3.1
Performance-based Restricted Equity Awards
 
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost 9.1
Weighted-average years expected to be recognized over (years) 1.4
Market-based Restricted Equity Awards
 
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost $ 2.0
Weighted-average years expected to be recognized over (years) 1.5