RESTRUCTURING CHARGES - Reconciliation of Beginning and Ending Restructuring Reserve Balances (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			$ 11.3
Costs incurred and charged to expense	$ 19.1	$ 9.1	26.8	$ 20.3
Costs paid or otherwise settled			(18.1)
Restructuring reserve, ending balance	20.0		20.0
Employee Separation Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			9.5
Costs incurred and charged to expense	16.9		22.0
Costs paid or otherwise settled			(12.6)
Restructuring reserve, ending balance	18.9		18.9
Other Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			1.8
Costs incurred and charged to expense	2.2		4.8
Costs paid or otherwise settled			(5.5)
Restructuring reserve, ending balance	$ 1.1		$ 1.1