SEVERANCE, RESTRUCTURING, AND OTHER EXIT COSTS - Schedule of Exit Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Restructuring Reserve [Roll Forward]
Beginning balance	$ 13.9
Charges	2.1	$ 2.8
Payments	(1.8)	$ (8.4)
Ending balance	14.2
Employee termination benefits
Restructuring Reserve [Roll Forward]
Beginning balance	2.7
Charges	0.1
Payments	(0.6)
Ending balance	2.2
Lease terminations
Restructuring Reserve [Roll Forward]
Beginning balance	7.6
Charges	2.0
Payments	(0.8)
Ending balance	8.8
Other contract terminations
Restructuring Reserve [Roll Forward]
Beginning balance	3.6
Charges	0.0
Payments	(0.4)
Ending balance	$ 3.2