Post Retirement Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Oct. 31, 2017	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Company's pension contributions		$ 14.4
Expected return on plan assets		5.51%
Annuity contract purchased		$ 49.2
Lump sum payments		45.2
Pension settlement charge		94.4
Pension settlement charge	$ 1.5	25.9
Amortization loss of prior service costs	0.2	0.2
Fair value of plan assets	$ 568.6	$ 568.6	$ 626.3	$ 624.7
Class A Common Stock
Defined Benefit Plan Disclosure [Line Items]
Common stock shares authorized (shares)	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
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Company's pension contributions		$ 11.1	$ 20.6	11.4
Company's pension contributions paid directly by the Company		3.3
Company's estimated pension contributions	$ 20.6	20.6
Pension settlement charge		101.7
Pension settlement charge		27.8	0.1	0.1
Aggregated accumulated benefit obligation	686.8	686.8	752.9
Fair value of plan assets	$ 568.6	$ 568.6	$ 626.3
Pension Plan | Class A Common Stock
Defined Benefit Plan Disclosure [Line Items]
Common stock shares authorized (shares)	247,507	247,507	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
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Company's pension contributions paid directly by the Company		$ 0.8	$ 1.1	1.5
Company's estimated pension contributions	$ 1.5	1.5
Aggregated accumulated benefit obligation	12.6	12.6	13.6
Fair value of plan assets	0.0	0.0	0.0
Foreign Plan | United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	188.9	188.9	185.1	208.4
Foreign Plan | United Kingdom | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Lump sum payments		7.3
Pension settlement charge		7.3
Pension settlement charge		1.2	0.0	0.0
Aggregated accumulated benefit obligation	186.9	186.9	171.4
Fair value of plan assets	188.9	188.9	185.1
Foreign Plan | Germany
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	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		0.7	0.0	0.0
Projected benefit obligation transferred to third party		1.8
Aggregated accumulated benefit obligation	38.1	38.1	39.1
Fair value of plan assets	$ 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		$ 8.3	$ 7.2	$ 7.8