Insurance - Casualty Program Insurance Reserves Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Net balance at beginning of year	$ 427.7	$ 412.5	$ 348.2
Change in case reserves plus IBNR Claims — current year	137.9	131.4	112.2
Change in case reserves plus IBNR Claims — prior years	(3.4)	10.2	23.1
Claims paid	(119.1)	(126.5)	(105.2)
GCA acquisition	0.0	0.1	34.1
Net balance at end of year	443.3	427.7	412.5
Recoverables	64.5	73.7	73.1
Gross balance at end of year	507.8	501.4	485.6
Provision related to discontinued operations	$ 1.0	$ 3.0	$ 10.0