Postretirement Benefits - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Jul. 31, 2014	Apr. 30, 2016	Apr. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Restructuring Charges	$ 3	$ 6		$ 6	$ 9
Defined Contribution Plan, Cost Recognized	8	8		15	17
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year				57
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	21	$ 32		40	$ 62
Effect of change in estimate approach on interest cost	9			18
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect of change in estimate approach on interest cost	$ 4			$ 8
Facility Closing [Member] | Chatham [Member] | Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Restructuring charges			$ 14