Post Retirement Benefit Plans - Fair Value Measurements for Pension Assets (Detail) - USD ($) $ in Millions	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets in the Fair Value Hierarchy	$ 286.2	$ 297.6
Investments Measured at Net Asset Value	308.6	271.0
Investments at Fair Value	594.8	568.6	$ 626.3
Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	100.8	126.0
Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	185.4	171.6
Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Mutual funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	203.7	202.8
Mutual funds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	63.0	76.7
Mutual funds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	140.7	126.1
Mutual funds | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Common stock
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	35.9	40.0
Common stock | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	35.9	40.0
Common stock | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Common stock | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Cash
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	1.9	9.3
Cash | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	1.9	9.3
Cash | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Cash | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Corporate bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	26.1	23.1
Corporate bonds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Corporate bonds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	26.1	23.1
Corporate bonds | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Government bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	17.8	18.5
Government bonds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Government bonds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	17.8	18.5
Government bonds | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Other assets
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.8	3.9
Other assets | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.0	0.0
Other assets | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	0.8	3.9
Other assets | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments at Fair Value	$ 0.0	$ 0.0