Quarterly report pursuant to Section 13 or 15(d)

Service Revenue (Summary of Changes in Deferred Costs to Obtain and Fulfill Contracts) (Details)

v3.20.2
Service Revenue (Summary of Changes in Deferred Costs to Obtain and Fulfill Contracts) (Details) - USD ($)
$ in Millions
3 Months Ended
Aug. 31, 2020
Aug. 31, 2019
Capitalized Contract Cost [Line Items]    
Amortization $ 47.3 $ 46.0
Costs To Obtain A Contract [Member]    
Capitalized Contract Cost [Line Items]    
Beginning balance 473.6 464.3
Capitalization of costs 37.2 35.9
Amortization (41.4) (40.2)
Ending balance 469.4 460.0
Costs To Fulfill A Contract [Member]    
Capitalized Contract Cost [Line Items]    
Beginning balance 67.3 66.1
Capitalization of costs 6.1 6.0
Amortization (5.9) (5.8)
Ending balance $ 67.5 $ 66.3