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