EMPLOYEE BENEFIT PLANS - Components of net periodic benefit cost (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 40.2	$ 36.7	$ 7.6
Interest cost	15.3	10.0	8.9
Expected return on plan assets	(7.5)	(7.2)	(3.7)
Amortization of prior service (credit) cost	(5.7)	(5.7)	(5.7)
Amortization of net loss (gain)	0.4	6.6	3.8
Settlements loss (gain) recognized	0.0	15.4	0.1
Curtailment (gain) loss recognized	(10.3)	(2.2)	(1.8)
Net periodic benefit cost	32.4	53.6	9.2
Other Post-Employment Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.4	1.9	1.1
Interest cost	2.0	1.8	1.9
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 loss (gain)	(0.1)	0.1	0.0
Settlements loss (gain) recognized	0.0	0.0	0.0
Curtailment (gain) loss recognized	(10.4)	0.0	(1.8)
Net periodic benefit cost	(13.0)	(2.1)	(4.7)
U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.0	0.0	0.0
Interest cost	0.7	1.6	3.4
Expected return on plan assets	0.0	(0.9)	(2.6)
Amortization of prior service (credit) cost	0.0	0.0	0.0
Amortization of net loss (gain)	(0.7)	2.3	1.2
Settlements loss (gain) recognized	0.0	15.9	0.0
Curtailment (gain) loss recognized	0.0	0.0	0.0
Net periodic benefit cost	0.0	18.9	2.0
International Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	38.8	34.8	6.5
Interest cost	12.6	6.6	3.6
Expected return on plan assets	(7.5)	(6.3)	(1.1)
Amortization of prior service (credit) cost	0.2	0.2	0.2
Amortization of net loss (gain)	1.2	4.2	2.6
Settlements loss (gain) recognized	0.0	(0.5)	0.1
Curtailment (gain) loss recognized	0.1	(2.2)	0.0
Net periodic benefit cost	45.4	$ 36.8	$ 11.9
International Plan | Other Post-Employment Benefits
Defined Benefit Plan Disclosure [Line Items]
Curtailment (gain) loss recognized	$ (10.4)