v2.4.0.6
Total Unrecognized Compensation and Weighted-average Years Expected to be Recognized (Detail) (USD $)
In Millions, unless otherwise specified
6 Months Ended
Jan. 28, 2012
Year
Service-based Restricted Equity Awards
 
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost $ 11.0
Weighted-average years expected to be recognized over (years) 4.2
Performance-based Restricted Equity Awards
 
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost 16.2
Weighted-average years expected to be recognized over (years) 1.9
Market-based Restricted Equity Awards
 
Unrecognized Share Based Compensation Expense [Line Items]  
Total unrecognized compensation cost $ 3.9
Weighted-average years expected to be recognized over (years) 1.8