RESTRUCTURING COSTS - Restructuring Costs by Type (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 59.6	$ 128.7	$ 89.7	$ 133.5
Transformation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs	62.5	$ 131.8	93.7	$ 139.4	$ 156.6
Cumulative through December 31, 2020	250.3		250.3
Severance and Employee Benefits \| Transformation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs			93.7		151.2
Cumulative through December 31, 2020	244.9		244.9
Fixed Asset Write-offs \| Transformation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(0.4)		(1.1)
Cumulative through December 31, 2020	(1.5)		(1.5)
Other Exit Costs \| Transformation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0.4		$ 6.5
Cumulative through December 31, 2020	$ 6.9		$ 6.9