RESTRUCTURING COSTS - Restructuring Costs by Program (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 12.4	$ 30.1
Transformation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs	12.4	31.2	$ 73.2	$ 156.6
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 0.0	$ (1.1)