RESTRUCTURING COSTS - Restructuring Costs by Type (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ (6.7)	$ 6.7	$ 134.2	$ 43.7
Turnaround Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs	6.0	0.0	152.6	0.0
Cumulative through March 31, 2020	152.6		152.6
Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs	(11.8)	$ 2.6	(16.2)	$ 31.3	$ 28.5	$ 106.5	$ 365.0
Cumulative through March 31, 2020	483.8		483.8
2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(1.9)		16.8	68.4
Cumulative through March 31, 2020	83.3		83.3
Severance and Employee Benefits | Turnaround Plan
Restructuring Cost and Reserve [Line Items]
Cumulative through March 31, 2020	146.7		146.7
Severance and Employee Benefits | Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(10.5)		(6.0)	67.5	333.9
Cumulative through March 31, 2020	384.9		384.9
Severance and Employee Benefits | 2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(1.9)		15.4	63.5
Cumulative through March 31, 2020	77.0		77.0
Third-Party Contract Terminations | Turnaround Plan
Restructuring Cost and Reserve [Line Items]
Cumulative through March 31, 2020	0.1		0.1
Third-Party Contract Terminations | Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(5.6)		4.5	19.3	22.4
Cumulative through March 31, 2020	40.6		40.6
Third-Party Contract Terminations | 2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0.0		(0.1)	0.2
Cumulative through March 31, 2020	0.1		0.1
Fixed Asset Write-offs | Turnaround Plan
Restructuring Cost and Reserve [Line Items]
Cumulative through March 31, 2020	(0.3)		(0.3)
Fixed Asset Write-offs | Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0.0		27.8	14.3	4.6
Cumulative through March 31, 2020	46.7		46.7
Fixed Asset Write-offs | 2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0.0		0.0	1.3
Cumulative through March 31, 2020	1.3		1.3
Other Exit Costs | Turnaround Plan
Restructuring Cost and Reserve [Line Items]
Cumulative through March 31, 2020	6.1		6.1
Other Exit Costs | Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(0.1)		2.2	5.4	$ 4.1
Cumulative through March 31, 2020	11.6		11.6
Other Exit Costs | 2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0.0		$ 1.5	$ 3.4
Cumulative through March 31, 2020	$ 4.9		$ 4.9