Basis of presentation - Accounting policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2020	Feb. 01, 2019	Feb. 02, 2018	May 03, 2019	Feb. 02, 2019	Feb. 03, 2018
Revenue recognition
Liability for outstanding gift cards	$ 6,000	$ 5,200
Breakage income related to gift card program	1,000	800	$ 600
Advertising costs
Advertising costs	91,000	70,500	68,800
Expenses related to vendor funding for cooperative advertising offset	$ 34,700	35,000	$ 33,800
New accounting guidance
Lease, Practical Expedients, Package [true false]	true
Lease, Practical Expedient, Lessor Single Lease Component [true false]	true
Lease, Practical Expedient, Use of Hindsight [true false]	false
Operating lease assets	$ 8,796,183
Operating lease liabilities	8,784,488
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 28,830	$ (41,316)
3.25% Senior Notes due April 15, 2023
Other comprehensive income
Debt maurity term	10 years
Accounting Standards Update 2016-16
New accounting guidance
Increase in deferred income tax liabilities						$ 41,300
Decrease in retained earnings						$ 41,300
Accounting Standards Update 2016-02
New accounting guidance
Operating lease assets					$ 8,000,000
Operating lease liabilities					8,000,000
Cumulative Effect of New Accounting Principle in Period of Adoption					$ 28,800
Accounting Standards Update 2018-02
New accounting guidance
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 900