Share-Based Compensation Cost by Award Type (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 9 Months Ended
Oct. 27, 2012
Oct. 29, 2011
Oct. 27, 2012
Oct. 29, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation $ 3,351 $ 2,730 $ 12,207 $ 7,483
Stock Options [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation 2,032 1,669 6,089 4,798
Restricted Stock Units (RSUs) [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation 1,318 1,049 6,104 2,529
Restricted Stock [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation $ 1 $ 12 $ 14 $ 156