SEGMENT REPORTING (Details)	3 Months Ended								9 Months Ended	12 Months Ended
	Feb. 03, 2018 USD ($)	Jan. 28, 2017 USD ($)	Oct. 29, 2016 USD ($)	Jul. 30, 2016 USD ($)	Apr. 30, 2016 USD ($)	Oct. 31, 2015 USD ($)	Aug. 01, 2015 USD ($)	May 02, 2015 USD ($)	Oct. 29, 2016 segment	Feb. 03, 2018 USD ($) state province distribution_center	Jan. 28, 2017 USD ($)	Jan. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of retail discount stores										14,800
Number of U.S. States, stores operating in | state										48
Number of Canadian provinces | province										5
Number of reportable Segments | segment									2
Net sales	$ 6,360,600,000	$ 5,635,300,000	$ 5,316,600,000	$ 5,281,200,000	$ 5,287,100,000	$ 5,001,600,000	$ 4,996,300,000	$ 5,085,800,000		$ 22,245,500,000	$ 20,719,200,000	$ 15,498,400,000
Gross profit	2,101,000,000	1,807,000,000	1,666,000,000	1,627,800,000	1,627,100,000	1,520,500,000	1,512,400,000	1,554,600,000		7,021,900,000	6,394,700,000	4,656,700,000
Depreciation and amortization expense										611,500,000	637,800,000	487,700,000
Operating income	765,600,000	586,500,000	$ 425,200,000	$ 419,500,000	$ 388,800,000	$ 342,400,000	$ 357,200,000	$ 418,700,000		1,999,100,000	1,704,800,000	1,049,700,000
Assets	16,332,800,000	15,701,600,000								16,332,800,000	15,701,600,000
Goodwill	5,025,200,000	5,023,500,000								5,025,200,000	5,023,500,000
Goodwill transfers										60,000,000
Dollar Tree [Member]
Segment Reporting Information [Line Items]
Price point										1.00
Net sales										11,164,400,000	10,138,700,000	9,336,400,000
Gross profit										3,998,500,000	3,584,700,000	3,249,300,000
Depreciation and amortization expense										251,800,000	241,300,000	223,400,000
Operating income										1,481,900,000	1,305,300,000	1,080,500,000
Assets	4,113,400,000	3,705,500,000								4,113,400,000	3,705,500,000
Goodwill	347,100,000	345,400,000								$ 347,100,000	345,400,000
Dollar Tree [Member] | UNITED STATES
Segment Reporting Information [Line Items]
Number of distribution centers | distribution_center										11
Dollar Tree [Member] | CANADA
Segment Reporting Information [Line Items]
Number of distribution centers | distribution_center										2
Family Dollar [Member]
Segment Reporting Information [Line Items]
Number of distribution centers | distribution_center										11
Net sales										$ 11,081,100,000	10,580,500,000	6,162,000,000
Gross profit										3,023,400,000	2,810,000,000	1,407,400,000
Depreciation and amortization expense										359,700,000	396,500,000	264,300,000
Operating income										517,200,000	399,500,000	$ (30,800,000)
Assets	12,219,400,000	11,996,100,000								12,219,400,000	11,996,100,000
Goodwill	$ 4,678,100,000	$ 4,678,100,000								$ 4,678,100,000	$ 4,678,100,000