Summary of Significant Accounting Policies - Product Warranty Liability (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended					6 Months Ended
	Apr. 30, 2013		Jan. 31, 2013	Apr. 30, 2012	Jan. 31, 2012	Apr. 30, 2013		Apr. 30, 2012		Oct. 31, 2012	Oct. 31, 2011
Product Liability Contingency [Line Items]
Product Warranty Accrual, Preexisting Increase Decrease Per Share, Net of Tax	$ 2.04		$ 0.50	$ 1.46	$ 1.70
Warranty Recoveries	$ 13		$ 27
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Accrued product warranty and deferred warranty revenue at beginning of period	1,221			844		1,221		844		1,118	598
Cost accrued and revenues deferred						226	[1]	236	[1]
Adjustments to pre-existing warranties						204	[2]	227	[2]
Payments and revenues recognized						(327)		(217)
Accrued product warranty and deferred warranty revenue at end of period	1,221			844		1,221		844		1,118	598
Less: Current portion	647			365		647		365
Noncurrent accrued product warranty and deferred warranty revenue	574			479		574		479
Product Warranty Accrual, Preexisting Increase (Decrease), net of tax				100	119
Extended Warranty Program:
Revenue extended warranty service contracts	33			24
Extended Warranty Programs [Member]
Extended Warranty Program:
Deferred Revenue	405					405				364
Revenue recognized under extended warranty programs	11			16		40		31
Product Warranty Accrual [Member]
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Adjustments to pre-existing warranties	164	[2]	40	104	123
Recoverable [Member]
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Adjustments to pre-existing warranties			$ 13

[1] .

[2] (B)In the first quarter of 2013, we recognized $13 million of charges for adjustments to pre-existing warranties for a specific warranty issue related to component parts from a supplier. Also during the quarter, we reached agreement for reimbursement from this supplier for this amount and other costs previously accrued. As a result of this agreement, we recognized a recovery of $27 million within Costs of products sold and recorded a receivable within Other current assets. In the second quarter of 2013, we recognized a warranty recovery of $13 million within Loss from discontinued operations, net of tax and recorded a receivable within Other current assets.