Leases - Lease Cost in Statements of Earnings (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Lessee, Lease, Description [Line Items]
Fixed operating lease expense		$ 73.6	$ 77.7	$ 148.6	$ 155.0
Variable operating lease expense	[1]	26.8	35.8	37.3	70.4
Sublease income		(1.3)	(1.2)	(2.5)	(2.4)
Net lease expense		99.1	$ 112.3	183.4	$ 223.0
Asia-Pacific | COVID-19
Lessee, Lease, Description [Line Items]
Rent concessions		$ 11.1		$ 21.4

[1] Includes a credit of $11.1 million and $21.4 million in the three and six months ended July 31, 2020, respectively, related to rent concessions negotiated in connection with retail store closures due to COVID-19.