RESTRUCTURING CHARGES - Reconciliation of Beginning and Ending Restructuring Reserve Balances (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			$ 11.3
Costs incurred and charged to expense	$ 4.4	$ 7.5	7.7	$ 11.2
Costs paid or otherwise settled			(12.2)
Restructuring reserve, ending balance	6.8		6.8
Employee Separation Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			9.5
Costs incurred and charged to expense	2.4		5.1
Costs paid or otherwise settled			(8.9)
Restructuring reserve, ending balance	5.7		5.7
Other Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			1.8
Costs incurred and charged to expense	2.0		2.6
Costs paid or otherwise settled			(3.3)
Restructuring reserve, ending balance	$ 1.1		$ 1.1