Post Retirement Benefit Plans - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Company's pension contributions		$ 26.5
Expected return on plan assets		4.12%
Lump sum payments				$ 45.2
Pension settlement charge	$ 0.9			25.9
Amortization loss of prior service costs		$ 0.2
Fair value of plan assets	$ 594.8	$ 1,017.0	$ 594.8	568.6
Defined Benefit Plan, Non-participating Annuity Contract, Settlements,Benefit Obligation				49.2
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement				94.4
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		$ 22.6	$ 85.5	14.4
Company's pension contributions paid directly by the Company		3.9
Company's estimated pension contributions		27.7
Pension settlement charge			1.3	27.8
Aggregated accumulated benefit obligation	$ 638.9	1,131.3	638.9
Fair value of plan assets	$ 594.8	$ 1,017.0	$ 594.8
Pension Plan | Class A common stock
Defined Benefit Plan Disclosure [Line Items]
Common stock shares authorized (shares)	247,504	175,320	247,504
Pension Plan | Class B common stock
Defined Benefit Plan Disclosure [Line Items]
Common stock shares authorized (shares)	160,710	111,270	160,710
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Company's pension contributions paid directly by the Company		$ 0.9	$ 1.0	0.8
Company's estimated pension contributions		1.3
Aggregated accumulated benefit obligation	$ 10.7	12.2	10.7
Fair value of plan assets	0.0	0.0	0.0
United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	178.7	209.8	178.7	188.9
United Kingdom | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Lump sum payments		4.7		7.3
Pension settlement charge			1.3	1.2
Aggregated accumulated benefit obligation	176.3	180.8	176.3
Fair value of plan assets	178.7	209.8	178.7
Germany
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0	0.0	0.0
Germany | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension settlement charge			0.0	0.7
Aggregated accumulated benefit obligation	37.2	42.6	37.2
Fair value of plan assets	$ 0.0	0.0	0.0
Defined Benefit Plan, Projected Benefit Obligation Transferred To Third Party				1.8
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		$ 21.8	$ 9.4	$ 8.3