INCOME TAXES - Unrecognized Tax Benefit Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Beginning balance	$ 263.6	$ 235.7	$ 256.7
Additions based on tax positions related to the current year	15.9	43.9	43.6
Additions for tax positions of prior years	42.9	8.3	29.6
Reductions for tax positions of prior years	(27.6)	(9.6)	(39.9)
Settlements	(0.1)	(2.7)	(42.3)
Lapses in statutes of limitations	(12.7)	(9.0)	(10.4)
Foreign currency translation	(4.1)	(3.0)	(1.6)
Ending balance	$ 277.9	$ 263.6	$ 235.7