Insurance - Instruments Used to Collateralize Insurance Obligations (Details) - USD ($) $ in Millions	Apr. 30, 2017	Oct. 31, 2016
Letters Of Credit
Total instruments used to collateralize insurance obligations	$ 190.8	$ 186.7
Standby letters of credit
Letters Of Credit
Instruments used to collateralize insurance obligations	120.1	118.3
Surety bonds
Letters Of Credit
Instruments used to collateralize insurance obligations	59.5	57.2
Restricted insurance deposits
Letters Of Credit
Instruments used to collateralize insurance obligations	$ 11.2	$ 11.2