OPERATING LEASES - Components of Lease Expense and Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 81.4	$ 91.6	$ 70.0
Variable lease cost	25.5	23.4	26.8
Less: sublease income	(1.9)	(2.1)	(0.6)
Total lease expense	105.0	112.9	$ 96.2
Operating cash flows from operating leases included in the measurement of lease liabilities	86.0	98.3
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 7.7	$ 36.7