Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.1
Service Revenue (Summary of Changes in Deferred Costs to Obtain and Fulfill Contracts) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Feb. 29, 2020
Feb. 28, 2019
Feb. 29, 2020
Feb. 28, 2019
Capitalized Contract Cost [Line Items]        
Amortization     $ 139.1 $ 134.8
Costs To Obtain A Contract [Member]        
Capitalized Contract Cost [Line Items]        
Beginning balance $ 456.9 $ 447.3 464.3 455.0
Capitalization of costs 49.4 47.9 122.7 118.2
Amortization (40.7) (39.6) (121.4) (117.6)
Ending balance 465.6 455.6 465.6 455.6
Costs To Fulfill A Contract [Member]        
Capitalized Contract Cost [Line Items]        
Beginning balance 66.4 65.8 66.1 65.4
Capitalization of costs 6.7 5.9 18.7 17.8
Amortization (6.0) (5.7) (17.7) (17.2)
Ending balance $ 67.1 $ 66.0 $ 67.1 $ 66.0