REVENUES FROM CONTRACTS WITH CUSTOMERS - Allowance for Credit Loss (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 56.2
Bad debt expense, net of recoveries	2.8
Write-offs	(13.3)
Other charges	(3.1)
Ending balance	$ 42.6