Revenue (Deferred Costs) (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018
Capitalized Contract Cost [Line Items]
Deferred contract costs	$ 2,352.3		$ 2,377.4
Amortization of deferred contract costs	216.9	$ 204.7
Deferred costs to obtain a contract
Capitalized Contract Cost [Line Items]
Deferred contract costs	1,445.7
Deferred costs to fulfill a contract
Capitalized Contract Cost [Line Items]
Deferred contract costs	$ 906.6