RESTRUCTURING CHARGES - Narrative (Details) - RGGA Program - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring costs recognized to date	$ 96.8	$ 68.8
Employee severance, other personnel benefits and other costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs recognized to date	73.3	$ 50.5
Lease and other restructuring-related charges
Restructuring Cost and Reserve [Line Items]
Restructuring costs recognized to date	$ 23.5