Leases (Narrative) (Details) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
	Nov. 30, 2019 USD ($) item	Nov. 30, 2019 USD ($) item	May 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Fixed payment operating lease expense	$ 9.6	$ 19.7	$ 42.9
Number of lease agreements, not yet commenced | item	2	2
Lease payments, not yet commenced	$ 5.2	$ 5.2
Minimum [Member]
Lessee, Lease, Description [Line Items]
Operating leases, remaining term of contract	1 year	1 year
Operating leases, contractual term		2019
Operating leases, renewal term	1 year	1 year
Maximum [Member]
Lessee, Lease, Description [Line Items]
Operating leases, remaining term of contract	10 years	10 years
Operating leases, contractual term		2029
Operating leases, renewal term	5 years	5 years
Lease not yet commenced, term of contract	9 years	9 years