RESTRUCTURING COSTS - Restructuring Costs by Type (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 0.0	$ (8.0)	$ 89.7	$ 125.5
Transformation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs	4.7	$ 3.5	98.4	$ 142.9	$ 156.6
Cumulative through March 31, 2021	255.0		255.0
Severance and Employee Benefits | Transformation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs			98.4		151.2
Cumulative through March 31, 2021	249.6		249.6
Fixed Asset Write-offs | Transformation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(0.4)		(1.1)
Cumulative through March 31, 2021	(1.5)		(1.5)
Other Exit Costs | Transformation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0.4		$ 6.5
Cumulative through March 31, 2021	$ 6.9		$ 6.9