Employee Benefits - Fair Value Measurement of Plan Assets (Details) - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	$ 159.5	$ 136.0	$ 121.0	$ 112.8
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	114.2
Significant Observable Inputs (Level 2)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	45.3
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	0.0
Cash and cash equivalents
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	18.8
Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	0.0
Cash and cash equivalents | Significant Observable Inputs (Level 2)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	18.8
Cash and cash equivalents | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	0.0
Equity mutual funds
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	91.9
Equity mutual funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	91.9
Equity mutual funds | Significant Observable Inputs (Level 2)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	0.0
Equity mutual funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	0.0
Hedging Strategy Funds
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	6.9
Hedging Strategy Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	6.9
Hedging Strategy Funds | Significant Observable Inputs (Level 2)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	0.0
Hedging Strategy Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	0.0
Bond mutual funds
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	41.9
Bond mutual funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	15.4
Bond mutual funds | Significant Observable Inputs (Level 2)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	26.5
Bond mutual funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Fair value of plan assets	$ 0.0