Restructuring and Related Costs - Restructuring and Related Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Restructuring Cost and Reserve [Line Items]
Cumulative charges	$ 57.6		$ 57.6
Restructuring Reserve [Roll Forward]
Balance, beginning of period			8.0
Costs recognized	5.2	$ 3.3	16.0	$ 19.3
Payments			(20.2)
Non-cash charges			(0.2)
Balance, end of period	3.7		3.7
External Support Fees
Restructuring Cost and Reserve [Line Items]
Cumulative charges	24.5		24.5
Restructuring Reserve [Roll Forward]
Balance, beginning of period			1.2
Costs recognized			8.6
Payments			(9.8)
Non-cash charges			0.0
Balance, end of period	0.0		0.0
Employee Severance
Restructuring Cost and Reserve [Line Items]
Cumulative charges	14.3		14.3
Restructuring Reserve [Roll Forward]
Balance, beginning of period			3.8
Costs recognized			1.0
Payments			(3.2)
Non-cash charges			0.0
Balance, end of period	1.6		1.6
Other Project Fees
Restructuring Cost and Reserve [Line Items]
Cumulative charges	9.4		9.4
Restructuring Reserve [Roll Forward]
Balance, beginning of period			0.5
Costs recognized			4.8
Payments			(4.9)
Non-cash charges			0.0
Balance, end of period	0.4		0.4
Lease Exit
Restructuring Cost and Reserve [Line Items]
Cumulative charges	4.7		4.7
Restructuring Reserve [Roll Forward]
Balance, beginning of period			2.5
Costs recognized			1.6
Payments			(2.3)
Balance, end of period	1.6		1.6
Asset Impairment
Restructuring Cost and Reserve [Line Items]
Cumulative charges	$ 4.7		$ 4.7