Postretirement Benefits - Components of Net Periodic Benefit Expense (Income) (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]
Service cost for benefits earned during the period	$ 5	$ 4	$ 10	$ 8
Interest on obligation	36	43	72	86
Amortization of cumulative loss	32	27	64	55
Amortization of Prior Service Cost (benefit)	0	0	0	0
Contractual termination benefits	0	0	0	0
Premium on pension insurance	1	1	1	1
Expected Return on Plan Assets	(47)	(48)	(94)	(96)
Net postretirement benefit expense	27	27	53	54
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost for benefits earned during the period	2	2	4	4
Interest on obligation	16	21	31	42
Amortization of cumulative loss	8	11	15	20
Amortization of Prior Service Cost (benefit)	(1)	(1)	(2)	(2)
Contractual termination benefits	0	0	0	(3)
Premium on pension insurance	0	0	0	0
Expected Return on Plan Assets	(9)	(9)	(17)	(18)
Net postretirement benefit expense	$ 16	$ 24	$ 31	$ 43