Insurance - Instruments Used to Collateralize Insurance Obligations (Details) - USD ($) $ in Millions	Jul. 31, 2018	Oct. 31, 2017
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	$ 236.3	$ 226.3
Standby letters of credit
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	146.7	137.6
Surety bonds
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	89.0	77.5
Restricted insurance deposits
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	$ 0.6	$ 11.2