INCOME TAXES - Reconciliation Of The Beginning And Ending Amount Of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$ 175.6	$ 107.7	$ 116.7
Additions based on tax positions related to the current year	4.7	33.3	8.1
Additions and reductions for tax positions of prior years (1)	(5.0)
Additions and reductions for tax positions of prior years (1)		37.5	0.3
Foreign currency	(9.6)	(1.6)	(8.1)
Reduction as a result of the lapse of statute of limitations	(26.0)	(1.3)	(2.6)
Reduction as a result of effective settlements	(3.5)	0.0	(6.7)
Balance at December 31	$ 136.2	$ 175.6	$ 107.7