Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2017	Jun. 30, 2016
Deferred income tax assets
Net operating loss carryforwards	$ 715.2	$ 563.9
Tax credit carry forwards	22.6	17.2
Deferred revenue	405.9	318.3
Accrued expenses	40.0	40.2
Other liabilities	17.4	25.5
Reserves against accounts receivable	18.2	14.8
Deferred compensation	20.3	15.5
Total deferred income tax assets	1,239.6	995.4
Valuation allowance	(111.1)	(135.3)
Net deferred tax assets	1,128.5	860.1
Deferred income tax liabilities.
Property and equipment	712.2	559.2
Intangible assets	412.4	321.5
Debt issuance costs	5.8	13.7
Total deferred income tax liabilities	1,130.4	894.4
Net deferred income tax liabilities	$ (1.9)	$ (34.3)