Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Service Revenue (Summary of Changes in Deferred Costs to Obtain and Fulfill Contracts) (Details)
$ in Millions
3 Months Ended
Aug. 31, 2018
USD ($)
Costs To Obtain A Contract [Member]  
Capitalized Contract Cost [Line Items]  
Beginning balance $ 455.0
Capitalization of costs 32.4
Amortization (38.9)
Ending balance 448.5
Costs To Fulfill A Contract [Member]  
Capitalized Contract Cost [Line Items]  
Beginning balance 65.4
Capitalization of costs 6.0
Amortization (5.7)
Ending balance $ 65.7