v2.4.0.6
Total Unrecognized Compensation and Weighted-average Years Expected to be Recognized (Detail) (USD $)
In Millions, unless otherwise specified
9 Months Ended
Apr. 28, 2012
Year
Service-based Restricted Equity Awards
 
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost $ 8.6
Weighted-average years expected to be recognized over (years) 3.9
Performance-based Restricted Equity Awards
 
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost 12.0
Weighted-average years expected to be recognized over (years) 1.7
Market-based Restricted Equity Awards
 
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost $ 2.6
Weighted-average years expected to be recognized over (years) 1.6