Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Dec. 31, 2020	Jul. 31, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate (percent)	9.70%	29.90%	28.90%		(444.60%)
Provisions for taxes	$ (1.5)	$ 24.0	$ 37.4		$ 43.2
Nondeductible impairment					$ 163.8
Effective income tax rate, excluding impairment					28.00%
Effected tax rate, provision from change of tax reserve	$ 2.9		3.1
Effected tax rate, benefit related energy efficiency		$ 0.8	$ 1.1		$ 1.2
Effected tax rate, nondeductible impairment loss, work opportunity tax provision					$ 1.9
Social security tax, employer, deferral, CARES Act				$ 132.0