EQUITY - Schedule of Share Repurchase Activities (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Equity, Class of Treasury Stock [Line Items]
Cost of shares repurchased (in millions)	$ 3.6	$ 36.3	$ 794.9
Common Class A
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased (in millions)	0.0	1.4	27.4
Cost of shares repurchased (in millions)	$ 0.0	$ 36.3	$ 767.0
Common Class A | Minimum
Equity, Class of Treasury Stock [Line Items]
Fair value of shares repurchased per share	$ 0.00	$ 25.35	$ 25.10
Common Class A | Maximum
Equity, Class of Treasury Stock [Line Items]
Fair value of shares repurchased per share	$ 0.00	$ 27.40	$ 30.35