Revenue Recognition - Additional Information (Detail)
3 Months Ended
May 02, 2020
USD ($)
segment
May 04, 2019
USD ($)
Feb. 01, 2020
USD ($)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]      
Percentage of cash back earned 2.00%    
Maximum annual cash back amount $ 500    
Cash back in form of electronic awards issued $ 20    
Cash back in form of electronic awards issued, expiration period 6 months    
Club membership term 12 months    
Number of reportable segments | segment 1    
My BJ's Perks Mastercard      
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]      
Percentage of cash back earned 5.00%    
Card outside of BJ's      
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]      
Percentage of cash back earned 2.00%    
BJ's Perks Rewards - earned awards      
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]      
Deferred revenue $ 28,600,000 $ 27,600,000 $ 26,700,000
BJ's Perks Rewards - royalty revenue      
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]      
Deferred revenue 14,800,000 13,300,000 14,800,000
Membership      
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]      
Deferred revenue 157,600,000 141,600,000 144,000,000.0
Gift card programs      
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]      
Deferred revenue 9,800,000 8,000,000.0 $ 10,300,000
Revenue recognized $ 10,200,000 $ 11,100,000  
Net sales | Revenue from rights concentration risk      
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]      
Concentration risk percentage 96.00%    
Total revenues | Revenue from rights concentration risk      
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]      
Concentration risk percentage 94.00%