Postretirement Benefits Obligations and Funded Status (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2009
Amounts recognized in our Consolidated Balance Sheet consist of: [Abstract]
Noncurrent liability	$ (3,210)	$ (2,097)
Net liability recognized	3,316	2,179
Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Projected benefit obligations	4,171	4,005
Accumulated benefit obligations	4,113	3,942
Fair Value of plan assets	2,392	2,479
Pension [Member]
Change in benefit obligations [Roll Forward]
Benefit obligations at beginning of year	4,005	3,850
Amendments and administrative changes	0	4
Service cost	17	18	15
Interest on obligations	189	209	234
Actuarial loss (gain)	(242)	(253)
Curtailments	(11)	(3)
Contractual termination benefits	(38)	(1)
Currency translation	26	1
Plan participants' contributions	0	0
Subsidy receipts	0	0
Benefits paid	(335)	(328)
Benefit obligations at end of year	4,171	4,005	3,850
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	2,479	2,317
Actual return on plan assets	75	369
Currency translation	25	(4)
Employer contributions	134	115
Benefits paid	(321)	(318)
Fair value of plan assets at end of year	2,392	2,479	2,317
Funded status at year end	(1,779)	(1,526)
Amounts recognized in our Consolidated Balance Sheet consist of: [Abstract]
Current liability	(13)	(10)
Noncurrent liability	(1,766)	(1,516)
Net liability recognized	1,779	1,526
Amounts recognized in our accumulated other comprehensive loss consists of: [Abstract]
Net actuarial loss	2,170	1,900
Net prior service cost (benefit)	5	8
Net amount recognized	2,175	1,908
Other Postretirement Benefit Plans, Defined Benefit [Member]
Change in benefit obligations [Roll Forward]
Benefit obligations at beginning of year	1,162	1,631
Amendments and administrative changes	302	(341)
Service cost	8	8	6
Interest on obligations	56	81	117
Actuarial loss (gain)	(547)	89
Curtailments	11	2
Contractual termination benefits	(6)	2
Retrospective payments due to retirees	15
Currency translation	0	0
Plan participants' contributions	34	32
Subsidy receipts	0	15
Benefits paid	(141)	(175)
Benefit obligations at end of year	2,000	1,162	1,631
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	509	473
Actual return on plan assets	22	78
Currency translation	0	0
Employer contributions	2	2
Benefits paid	(70)	(44)
Fair value of plan assets at end of year	463	509	473
Funded status at year end	(1,537)	(653)
Amounts recognized in our Consolidated Balance Sheet consist of: [Abstract]
Current liability	(93)	(72)
Noncurrent liability	(1,444)	(581)
Net liability recognized	1,537	653
Amounts recognized in our accumulated other comprehensive loss consists of: [Abstract]
Net actuarial loss	654	92
Net prior service cost (benefit)	(21)	(352)
Net amount recognized	$ 633	$ (260)