Postretirement Benefits - Defined Benefit Plan (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2013	Apr. 30, 2012
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Contributions by Employer	$ 30	$ 53	$ 57	$ 82
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	109		109
Early Retiree Reinsurance Program [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Contributions by Plan Participants	$ 0	$ 0	$ 0	$ 3