Leases - Additional Information (Detail) $ in Millions	3 Months Ended	6 Months Ended
	Nov. 30, 2019 USD ($)	Nov. 30, 2019 USD ($)
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	$ 21.5	$ 42.2
Operating lease costs	17.8	35.9
Other costs	3.7	6.3
Operating lease obligations	$ 17.1	34.0
ROU asset recognized in exchange for operating lease liability		$ 41.1
Operating lease, weighted-average remaining lease term	9 years 2 months 12 days	9 years 2 months 12 days
Operating lease, weighted-average discount rate	3.80%	3.80%
Operating lease liability, current	$ 51.0	$ 51.0
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherAccruedLiabilitiesCurrent	us-gaap:OtherAccruedLiabilitiesCurrent
Minimum
Lessee Lease Description [Line Items]
Lessee, operating lease, renewal term	1 year	1 year
Maximum
Lessee Lease Description [Line Items]
Lessee, operating lease, renewal term	5 years	5 years