Share-Based Compensation Unrecognized Compensation Expense and Period for Recognition (Details) (USD $)
In Millions, unless otherwise specified
9 Months Ended
Oct. 27, 2012
Years
Stock Options [Member]
 
Unrecognized Compensation Expense and Period for Recognition [Line Items]  
Unrecognized Share-based Compensation Expense $ 17.6
Unrecognized Share-based Compensation Expense, Period for Recognition 1.3
Restricted Stock Units (RSUs) [Member]
 
Unrecognized Compensation Expense and Period for Recognition [Line Items]  
Unrecognized Share-based Compensation Expense $ 18.6
Unrecognized Share-based Compensation Expense, Period for Recognition 1.5