Postretirement Benefits - Schedule of Change in Benefit Obligation and Plan Assets (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Oct. 31, 2013	Oct. 31, 2013 Pension Plan, Defined Benefit [Member]	Oct. 31, 2012 Pension Plan, Defined Benefit [Member]	Oct. 31, 2011 Pension Plan, Defined Benefit [Member]	Oct. 31, 2013 Other Postretirement Benefit Plan, Defined Benefit [Member]	Oct. 31, 2012 Other Postretirement Benefit Plan, Defined Benefit [Member]	Oct. 31, 2011 Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligations at beginning of year		$ 4,492	$ 4,171		$ 1,866	$ 2,000
Amendments		3	0		0	0
Service cost		20	17	17	7	7	8
Interest on obligations		143	169	189	62	83	56
Actuarial loss (gain)		(334)	462		(142)	(72)
Curtailments	4	33	(4)		0	0
Contractual termination benefits		0	2		0	(3)
Retrospective payments due to retirees		0	0		0	(2)
Currency translation		(15)	(5)		0	0
Plan participants' contributions		0	0		28	20
Subsidy receipts		0	0		41	20
Benefits paid		333	328		188	187
Benefit obligations at end of year		3,943	4,492	4,171	1,674	1,866	2,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		2,411	2,392		437	463
Actual return on plan assets		284	186		66	27
Currency translation		(22)	(9)		0	0
Employer contributions		165	157		3	19
Benefits paid		319	315		59	72
Fair value of plan assets at end of year		2,519	2,411	2,392	447	437	463
Funded status at year end		$ (1,424)	$ (2,081)		$ (1,227)	$ (1,429)