Stock-Based Compensation Plans - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended	12 Months Ended
	Mar. 19, 2022	Jan. 31, 2026	Jan. 31, 2026	Feb. 01, 2025	Feb. 03, 2024	Jun. 10, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of options outstanding		$ 0.8	$ 0.8
Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of recognition (in months)			9 months 18 days
Intrinsic value of options exercised			$ 0.1	$ 0.1	$ 0.1
Unrecognized compensation expense		1.2	1.2
Stock option \| Board of Directors Chairman
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period (in shares)	2,252,587
Aggregate intrinsic value of options outstanding	$ 135.6
Executive agreement term	5 years
Term	10 years
Vesting period	5 years
Accelerated vesting of options		27.1
Stock option \| Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)				6 years	6 years
Aggregate intrinsic value of options outstanding		5.6	$ 5.6	$ 4.9
Term			10 years
Vesting period			3 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period			3 years
Total fair value of vested instruments other than options			$ 70.0	$ 55.3	$ 53.8
Weighted average grant date fair value (dollars per share)			$ 76.47	$ 131.89	$ 141.70
Unrecognized compensation expense		62.0	$ 62.0
Weighted average period of recognition (in months)			1 year 7 months 6 days
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			2 years 9 months 18 days	2 years 9 months 18 days	2 years 9 months 18 days
Service period			3 years
Total fair value of vested instruments other than options			$ 7.6	$ 9.1	$ 8.7
Weighted average grant date fair value (dollars per share)			$ 78.85	$ 114.98	$ 129.24
Unrecognized compensation expense		$ 10.4	$ 10.4
Weighted average period of recognition (in months)			1 year 4 months 24 days
Vesting period			3 years
2021 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant (in shares)						6,500,000
Director Deferred Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of the share price of common stock used in the calculation to determine the number of options issued to a director (in hundredths)			33.00%
Director Deferred Compensation Plan \| Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			10 years

DOLLAR TREE, INC. 10-K