Postretirement Benefits - Components of Net Periodic Benefit Expense (Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 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	$ 5	$ 15	$ 13
Interest on obligation	36	43	108	129
Amortization of cumulative loss	31	27	95	82
Amortization of Prior Service Cost (benefit)	1	1	1	1
Contractual termination benefits	0	0	0	0
Premium on pension insurance	0	0	1	1
Expected Return on Plan Assets	(48)	(49)	(142)	(145)
Net postretirement benefit expense	25	27	78	81
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	1	1	5	5
Interest on obligation	16	20	47	62
Amortization of cumulative loss	7	10	22	30
Amortization of Prior Service Cost (benefit)	(1)	(2)	(3)	(4)
Contractual termination benefits	0	0	0	(3)
Premium on pension insurance	0	0	0	0
Expected Return on Plan Assets	(8)	(8)	(25)	(26)
Net postretirement benefit expense	$ 15	$ 21	$ 46	$ 64