Restructuring and Related Costs - Restructuring and Related Liabilities (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]
Balance, beginning of period			$ 7.0
Costs Recognized	$ 1.8	$ 2.7	5.0	$ 6.5
Payments			(6.0)
Non-Cash Items			(2.7)
Balance, end of period	3.2		3.2
Employee severance
Restructuring Reserve [Roll Forward]
Balance, beginning of period			3.0
Costs Recognized			0.2
Payments			(1.5)
Non-Cash Items			0.0
Balance, end of period	1.7		1.7
External support fees
Restructuring Reserve [Roll Forward]
Balance, beginning of period			0.5
Costs Recognized			1.4
Payments			(0.5)
Non-Cash Items			0.0
Balance, end of period	1.5		1.5
Other project fees
Restructuring Reserve [Roll Forward]
Balance, beginning of period			0.7
Costs Recognized			3.3
Payments			(3.9)
Non-Cash Items			(0.2)
Balance, end of period	0.0		0.0
Lease exit costs and asset impairment
Restructuring Reserve [Roll Forward]
Balance, beginning of period			2.7
Costs Recognized			0.0
Payments			(0.2)
Non-Cash Items			(2.5)
Balance, end of period	$ 0.0		$ 0.0