Insurance - Instruments Used to Collateralize Insurance Obligations (Details) - USD ($) $ in Millions	Apr. 30, 2018	Oct. 31, 2017
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	$ 225.3	$ 226.3
Standby letters of credit
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	136.7	137.6
Surety bonds
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	78.2	77.5
Restricted insurance deposits
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	$ 10.4	$ 11.2