RESTRUCTURING CHARGES - Restructuring and Related Charges Activity (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
Total Restructuring Charges
Restructuring Reserve [Roll Forward]
Charges incurred during period	$ 22.8
RGGA Program
Restructuring Reserve [Roll Forward]
Charges incurred through beginning of period	68.8
Charges incurred during period	28.0
Charges incurred through end of period	96.8
RGGA Program | Total Restructuring Charges
Restructuring Reserve [Roll Forward]
Charges incurred through beginning of period	50.5
Charges incurred during period	22.8
Charges incurred through end of period	73.3
RGGA Program | Employee Severance and Other Personnel Benefits
Restructuring Reserve [Roll Forward]
Charges incurred through beginning of period	48.6
Charges incurred during period	3.5
Charges incurred through end of period	52.1
RGGA Program | Other Costs
Restructuring Reserve [Roll Forward]
Charges incurred through beginning of period	1.9
Charges incurred during period	19.3
Charges incurred through end of period	21.2
RGGA Program | Leases
Restructuring Reserve [Roll Forward]
Charges incurred through beginning of period	12.6
Charges incurred during period	3.9
Charges incurred through end of period	16.5
RGGA Program | Other Related Charges
Restructuring Reserve [Roll Forward]
Charges incurred through beginning of period	5.7
Charges incurred during period	1.3
Charges incurred through end of period	$ 7.0