Fair Value Measurements (Details)
3 Months Ended 6 Months Ended
Jul. 29, 2017
USD ($)
Apr. 29, 2017
USD ($)
Jul. 30, 2016
USD ($)
stores
Jul. 29, 2017
USD ($)
stores
Jul. 30, 2016
USD ($)
stores
Jan. 28, 2017
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Impairment charge $ 0 $ 5,500,000 $ 800,000 $ 5,479,000 $ 829,000  
Number of stores impaired during the period | stores     2 17 2  
Level 1 [Member] | Recurring [Member]            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Money market funds 141,813,000     $ 141,813,000   $ 177,551,000
Level 2 [Member] | Recurring [Member]            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Money market funds 0     0   0
Level 3 [Member] | Recurring [Member]            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Money market funds $ 0     $ 0   $ 0