Benefit plans (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 28, 2022	Jan. 29, 2021	Jan. 31, 2020
Benefit plans
Matching contribution expense related to the Company's 401(k) plan	$ 34.0	$ 30.1	$ 25.0
Compensation expense for the Dollar General Corporation CDP/SERP Plan	$ 1.3	$ 0.9	$ 0.8