Leases - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2018
Lessee Lease Description [Line Items]
Lessee, operating lease, option to extend description	Some leases include one or more options to renew, generally at our sole discretion, with renewal terms that can extend the lease term from one to five years or more.
Lessee, operating lease, existence of option to extend	true
Lessee, operating lease, option to terminate description	In addition, certain leases contain termination options, where the rights to terminate are held by either us, the lessor, or both parties.
Lessee, operating lease, existence of option to terminate	true
Lease costs	$ 84.2
Operating lease costs	73.7
Other costs	10.5
Rental expenses for all operating lease		$ 64.9	$ 64.3
Operating lease obligations	69.4
ROU asset recognized in exchange for operating lease liability	$ 61.6
Operating lease, weighted-average remaining lease term	9 years 1 month 6 days
Operating lease, weighted-average discount rate	3.70%
Operating lease liability, current	$ 52.6
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherAccruedLiabilitiesCurrent
Minimum
Lessee Lease Description [Line Items]
Lessee, operating lease, renewal term	1 year
Maximum
Lessee Lease Description [Line Items]
Lessee, operating lease, renewal term	5 years