Income Taxes - Reconciliation of Provision for Income Taxes Attributable to Income from Operations and Amount Computed by Applying Statutory Federal Income Tax Rate to Income Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Income Tax Disclosure [Abstract]
Computed expected provision for taxes	$ 56.0	$ 100.3	$ 77.5
Income earned outside the United States subject to different tax rates	(54.7)	(85.6)	(97.5)
State taxes, net of federal income tax benefit	1.9	0.4	(4.9)
Foreign source income subject to United States tax	32.0	16.1	0.0
U.S. tax reform	0.0	(5.8)	214.6
Incentive stock option compensation and non-deductible employee compensation	(4.4)	(7.8)	(11.1)
Deferred tax asset step-up	(9.0)	(6.7)	(1.9)
US provision-to-return	7.0	4.4	(0.7)
Tax accrual adjustment	(0.1)	(1.5)	13.9
Other, net	(0.6)	(3.1)	2.1
Income tax provision	$ 28.1	$ 10.7	$ 192.0