INCOME TAXES (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Jun. 30, 2017
Deferred income tax assets
Net operating loss carryforwards	$ 545.2	$ 715.2
Tax credit carry forwards	17.9	22.6
Deferred revenue	305.0	405.9
Accrued expenses	41.4	40.0
Other liabilities	2.3	17.4
Reserves against accounts receivable	15.8	18.2
Deferred compensation	11.2	20.3
Total deferred income tax assets	938.8	1,239.6
Valuation allowance	(72.9)	(111.1)
Net deferred tax assets	865.9	1,128.5
Deferred income tax liabilities.
Property and equipment	680.9	712.2
Intangible assets	293.3	412.4
Debt issuance costs	2.4	5.8
Total deferred income tax liabilities	976.6	1,130.4
Deferred tax liability, net	(5.1)
Net deferred income tax liabilities	$ (105.6)	$ (1.9)