Annual report pursuant to Section 13 and 15(d)

EMPLOYEE BENEFIT PLANS (Details)

v3.8.0.1
EMPLOYEE BENEFIT PLANS (Details)
$ in Millions
 12 Months Ended
Feb. 03, 2018
USD ($)
Years_Old
hour
Jan. 28, 2017
USD ($)
Jan. 30, 2016
USD ($)
Profit Sharing and 401(k) Retirement Plan [Abstract]      
Age over which all employees have 401K benefits available | Years_Old 21    
Employee service years required for available 401K benefits (in years) one    
Minimum hours in a 401K qualifying one year period (in hours) | hour 1,000    
Profit Sharing Vesting Schedule      
Percentage Vested in the Profit Sharing Plan After Two Years of Service (in Hundreths) 20.00%    
Years of Service Required to vest 20% in the Profit Sharing Plan 2 years    
Percentage Vested in the Profit Sharing Plan After Three Years of Service (in Hundreths) 40.00%    
Years of Service Required to vest 40% in the Profit Sharing Plan 3 years    
Percentage Vested in the Profit Sharing Plan After Four Years of Service (in Hundreths) 60.00%    
Years of Service Required to vest 60% in the Profit Sharing Plan 4 years    
Percentage Vested in the Profit Sharing Plan After Five Years of Service (in Hundreths) 100.00%    
Years of Service Required to vest 100% in the Profit Sharing Plan 5 years    
Deferred Compensation Plan [Abstract]      
Cumulative participant deferrals $ 5.7 $ 5.2  
Family Dollar [Member]      
Deferred Compensation Plan [Abstract]      
Cumulative participant deferrals 15.0 14.6  
Postemployment Retirement Benefits [Member]      
Profit Sharing and 401(k) Retirement Plan [Abstract]      
Contributions to expenses of the plans 52.9 49.1 $ 42.8
Dollar Tree Retirement Savings Plan, formerly Dollar Tree Inc. Affiliates and Subsidiaries Profit Sharing and 401(k) Retirement Plan [Member] | Postemployment Retirement Benefits [Member]      
Profit Sharing and 401(k) Retirement Plan [Abstract]      
Contributions to expenses of the plans 52.9 39.9 36.6
Family Dollar Employee Savings and Retirement Plan and Trust [Member] | Postemployment Retirement Benefits [Member]      
Profit Sharing and 401(k) Retirement Plan [Abstract]      
Contributions to expenses of the plans 0.0 9.2 6.2
Cost of Sales [Member] | Postemployment Retirement Benefits [Member]      
Profit Sharing and 401(k) Retirement Plan [Abstract]      
Contributions to expenses of the plans $ 7.8 $ 7.9 $ 7.4