Post Retirement Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Company's pension contributions			$ 85.5
Expected return on plan assets			4.53%
Annuity contract purchased				$ 49.2
Lump sum payments				45.2
Pension settlement charge				94.4
Pension settlement charge	$ 0.9	$ 1.5		25.9
Amortization loss of prior service costs	0.2		$ 0.2
Fair value of plan assets	$ 594.8	$ 568.6	$ 594.8	$ 568.6	$ 626.3
Class A Common Stock
Defined Benefit Plan Disclosure [Line Items]
Common stock shares authorized (shares)	128,000,000	128,000,000	128,000,000	128,000,000
Class B Common Stock
Defined Benefit Plan Disclosure [Line Items]
Common stock shares authorized (shares)	69,120,000	69,120,000	69,120,000	69,120,000
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Company's pension contributions			$ 81.7	$ 14.4	20.6
Company's pension contributions paid directly by the Company			3.8
Company's estimated pension contributions	$ 14.3		14.3
Pension settlement charge				101.7
Pension settlement charge			1.3	27.8	0.1
Aggregated accumulated benefit obligation	638.9	$ 686.8	638.9	686.8
Fair value of plan assets	$ 594.8	$ 568.6	$ 594.8	$ 568.6
Pension Plan | Class A Common Stock
Defined Benefit Plan Disclosure [Line Items]
Common stock shares authorized (shares)	247,504	247,507	247,504	247,507
Pension Plan | Class B Common Stock
Defined Benefit Plan Disclosure [Line Items]
Common stock shares authorized (shares)	160,710	160,710	160,710	160,710
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Company's pension contributions paid directly by the Company			$ 1.0	$ 0.8	1.1
Company's estimated pension contributions	$ 1.3		1.3
Aggregated accumulated benefit obligation	10.7	$ 12.6	10.7	12.6
Fair value of plan assets	0.0	0.0	0.0	0.0
Foreign Plan | United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	178.7	188.9	178.7	188.9	185.1
Foreign Plan | United Kingdom | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Lump sum payments			4.7	7.3
Pension settlement charge				7.3
Pension settlement charge			1.3	1.2	0.0
Aggregated accumulated benefit obligation	176.3	186.9	176.3	186.9
Fair value of plan assets	178.7	188.9	178.7	188.9
Foreign Plan | Germany
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0	0.0	0.0	0.0
Foreign Plan | Germany | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension settlement charge				0.0
Pension settlement charge			0.0	0.7	0.0
Projected benefit obligation transferred to third party				1.8
Aggregated accumulated benefit obligation	37.2	38.1	37.2	38.1
Fair value of plan assets	$ 0.0	$ 0.0	0.0	0.0
Defined benefit plan, net periodic benefit cost (credit), gain (loss) due to sale of business				0.7
401 (k) Savings Plan
Defined Contribution Plan Disclosure [Line Items]
Company contributions to 401(k) plans			$ 9.4	$ 8.3	$ 7.2