Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate (percent)	27.30%	(8.40%)	26.90%	(21.40%)
Income tax provision	$ (11.7)	$ (10.6)	$ (38.9)	$ (19.2)
Nondeductible impairment		$ 163.8		$ 163.8
Effective income tax rate, excluding impairment		(28.10%)		(25.90%)
Nondeductible impairment loss, work opportunity tax provision				$ 1.5
Social security tax, employer, deferral, CARES Act			$ 132.0