EMPLOYEE BENEFIT PLANS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 34.2	$ 34.5	$ 40.2
Interest cost	11.4	15.6	15.3
Expected return on plan assets	(8.4)	(8.2)	(7.5)
Amortization of prior service (credit) cost	(6.7)	(5.7)	(5.7)
Amortization of net (gain) loss	0.5	(0.5)	0.4
Settlements (gain) loss recognized	(0.2)	(0.8)	0.0
Curtailment (gain) loss recognized	(14.9)	(5.4)	(10.3)
Net periodic benefit cost	15.9	29.5	32.4
Other Post-Employment Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.1	1.2	1.4
Interest cost	1.7	2.1	2.0
Expected return on plan assets	0.0	0.0	0.0
Amortization of prior service (credit) cost	(5.9)	(5.9)	(5.9)
Amortization of net (gain) loss	(0.1)	(0.1)	(0.1)
Settlements (gain) loss recognized	0.0	0.0	0.0
Curtailment (gain) loss recognized	(0.8)	0.0	(10.4)
Net periodic benefit cost	(4.0)	(2.7)	(13.0)
United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.0	0.0	0.0
Interest cost	0.6	0.7	0.7
Expected return on plan assets	0.0	0.0	0.0
Amortization of prior service (credit) cost	0.0	0.0	0.0
Amortization of net (gain) loss	0.7	(0.7)	(0.7)
Settlements (gain) loss recognized	0.0	0.0	0.0
Curtailment (gain) loss recognized	0.0	0.0	0.0
Net periodic benefit cost	1.3	0.0	0.0
International | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	33.1	33.3	38.8
Interest cost	9.1	12.8	12.6
Expected return on plan assets	(8.4)	(8.2)	(7.5)
Amortization of prior service (credit) cost	(0.8)	0.2	0.2
Amortization of net (gain) loss	(0.1)	0.3	1.2
Settlements (gain) loss recognized	(0.2)	(0.8)	0.0
Curtailment (gain) loss recognized	(14.1)	(5.4)	0.1
Net periodic benefit cost	$ 18.6	$ 32.2	45.4
International | Other Post-Employment Benefits
Defined Benefit Plan Disclosure [Line Items]
Curtailment (gain) loss recognized			$ (10.4)