RESTRUCTURING COSTS - Summary of Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 6.7	$ 42.7	$ 43.7	$ 75.6
Cumulative through March 31, 2019	(0.1)		(0.1)
Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs	2.6	$ 33.3	31.3	$ 58.2	$ 106.5	$ 364.2
Cumulative through March 31, 2019	502.0		502.0
2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			13.3		68.4
Cumulative through March 31, 2019	81.7		81.7
Severance and Employee Benefits | Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0.3		67.5	333.9
Cumulative through March 31, 2019	401.7		401.7
Severance and Employee Benefits | 2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			12.1		63.5
Cumulative through March 31, 2019	75.6		75.6
Third-Party Contract Terminations | Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs			1.5		19.3	22.4
Cumulative through March 31, 2019	43.2		43.2
Third-Party Contract Terminations | 2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(0.1)		0.2
Cumulative through March 31, 2019	0.1		0.1
Fixed Asset Write-offs | Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs			27.8		14.3	4.6
Cumulative through March 31, 2019	46.7		46.7
Fixed Asset Write-offs | 2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0.0		1.3
Cumulative through March 31, 2019	1.3		1.3
Other Exit Costs | Global Integration Activities
Restructuring Cost and Reserve [Line Items]
Restructuring costs			1.7		5.4	$ 3.3
Cumulative through March 31, 2019	10.4		10.4
Other Exit Costs | 2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs			1.3		$ 3.4
Cumulative through March 31, 2019	$ 4.7		$ 4.7