ACCRUED LIABILITIES (Schedule of Accrued Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jun. 30, 2018
Accrued Liabilities, Current [Abstract]
Accrued compensation and benefits	$ 29.2	$ 44.9
Accrued property and equipment purchases	81.5	74.5
Network expense accruals	100.6	112.5
Other accrued taxes	36.4	11.8
Accrued professional fees	4.6	4.3
Other accruals	54.5	65.0
Less liabilities held for sale		(0.7)
Total	$ 306.8	$ 312.3