Postretirement Benefits - Components of Postretirement Benefits Included in Operations (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Net postretirement benefits expense	$ 160	$ 177	$ 203
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net postretirement benefits expense	106	116	122
Health and Life Insurance Benefits
Defined Benefit Plan Disclosure [Line Items]
Net postretirement benefits expense	$ 54	$ 61	$ 81