REVENUE (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Accounts Receivable, Less Allowance		$ 2,479.0		$ 2,454.5	$ 2,088.9
Contract Assets (Current)				49.0	50.5
Contract Assets (Long-Term)				177.8	178.2
Contract Liabilities (Current)				243.9	242.8
Contract Liabilities (Long-Term)				10.7	10.4
Bad debt expense related to the expected impact from the COVID-19 pandemic	$ 21.0
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	36.5
Adjustment upon adoption of ASU 2016-13	77.1		$ 36.5	$ 77.1	36.5
Bad debt expense	63.6
Uncollectible accounts written off, net of recoveries	(26.0)
Ending balance	$ 77.1		$ 36.5
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201802Member	us-gaap:AccountingStandardsUpdate201613Member
Cumulative effect, period of adoption, adjustment
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 3.0
Adjustment upon adoption of ASU 2016-13	$ 3.0		$ 3.0		$ 3.0
Ending balance			$ 3.0