Share-based payments (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 28, 2022	Jan. 29, 2021	Jan. 31, 2020
Share-based payments
Number of shares of common stock authorized for grant	11,838,143
Share-based compensation expense
Pre-tax	$ 78,178	$ 68,609	$ 48,589
Net of tax	57,774	$ 50,702	$ 36,393
Total unrecognized compensation cost	$ 87,400
Expected weighted average expense recognition period (in years)	1 year 9 months 18 days
Employees
Share-based payments
Vesting period	4 years
Board members
Share-based payments
Vesting period	1 year
Stock options
Weighted average for key assumptions used in determining the fair value
Expected dividend yield (as a percent)	0.90%	0.90%	1.10%
Expected stock price volatility (as a percent)	26.50%	26.40%	25.30%
Weighted average risk-free interest rate (as a percent)	0.80%	0.70%	2.30%
Expected term of options	4 years 10 months 24 days	5 years 2 months 12 days	6 years 2 months 12 days
Options Issued
Balance at the beginning of the period (in shares)	2,911,540
Granted (in shares)	607,213
Exercise of share-based awards (in shares)	(1,042,403)
Canceled (in shares)	(128,840)
Balance, at the end of the period (in shares)	2,347,510	2,911,540
Exercisable at the end of the period (in shares)	942,531
Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$ 104.69
Granted (in dollars per share)	195.34
Exercised (in dollars per share)	86.81
Canceled (in dollars per share)	149.42
Balance at the end of the period (in dollars per share)	133.62	$ 104.69
Exercisable at the end of the period (in dollars per share)	$ 95.10
Remaining Contractual Term
Balance, at the end of the period	7 years 1 month 6 days
Exercisable at the end of the period	5 years 4 months 24 days
Intrinsic Value
Balance at the end of the period	$ 166,856
Exercisable at the end of the period	$ 102,992
Weighted average grant date fair value (in dollars per share)	$ 42.89	$ 34.60	$ 30.67
Intrinsic value of options exercised	$ 132,300	$ 116,100	$ 26,600
Share-based compensation expense
Pre-tax	21,452	19,933	16,128
Net of tax	$ 15,853	$ 14,730	$ 12,080
Performance Stock Units
Share-based payments
Vesting period	3 years
Weighted average grant date fair value of awards issued (in dollars per share)	$ 193.55	$ 154.53	$ 117.13
Intrinsic Value
Balance at the end of the period	$ 68,909
Units Issued
Awards outstanding at the beginning of the period (in shares or rights)	367,053
Granted (in shares or rights)	183,355
Converted to common stock (in shares or rights)	(199,309)
Canceled (in shares or rights)	(13,856)
Awards outstanding at the end of the period (in shares or rights)	337,243	367,053
Share-based compensation expense
Pre-tax	$ 33,234	$ 27,388	$ 13,343
Net of tax	$ 24,560	$ 20,240	$ 9,994
Performance Stock Units | Minimum
Share-based payments
Performance period	1 year
Performance Stock Units | Less than
Share-based payments
Performance period	3 years
Restricted Stock Units
Share-based payments
Weighted average grant date fair value of awards issued (in dollars per share)	$ 193.76	$ 155.73	$ 117.20
Intrinsic Value
Balance at the end of the period	$ 62,753
Units Issued
Awards outstanding at the beginning of the period (in shares or rights)	369,871
Granted (in shares or rights)	165,701
Converted to common stock (in shares or rights)	(177,277)
Canceled (in shares or rights)	(51,177)
Awards outstanding at the end of the period (in shares or rights)	307,118	369,871
Share-based compensation expense
Pre-tax	$ 23,492	$ 21,288	$ 19,118
Net of tax	$ 17,361	$ 15,732	$ 14,319
Restricted Stock Units | Employees
Share-based payments
Vesting period	3 years