Summary of Significant Accounting Policies - Product Warranty Liability (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				9 Months Ended
	Jul. 31, 2016	Apr. 30, 2016	Jul. 31, 2015	Jan. 31, 2015	Jul. 31, 2016	Jul. 31, 2015	Oct. 31, 2015	Oct. 31, 2014
Product Liability Contingency [Line Items]
Product Warranty Accrual	$ 868		$ 1,016		$ 868	$ 1,016	$ 994	$ 1,197
Product Warranty Accrual, Warranties Issued					141	208
Product Warranty Accrual, Currency Translation, Increase (Decrease)					2	(7)
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Adjustments to pre-existing warranties(A)(B)					70	(38)
Extended Warranty Program:
Product Warranty Accrual, Payments					(339)	(344)
Product Warranty Accrual, Current	423		466		423	466
Product Warranty Accrual, Noncurrent	445		550		445	550
Extended Warranty Programs [Member]
Extended Warranty Program:
Deferred Revenue, Revenue Recognized	37		40		113	115
Deferred Revenue	$ 345				$ 345		$ 401
Product Warranty Accrual [Member]
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Adjustments to pre-existing warranties(A)(B)		$ 46		$ (57)
Product Warranty Accrual, Preexisting Increase Decrease Per Share, Net of Tax		$ 0.56		$ (0.70)
Amortization of Loss Reserves [Member]
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Prior Period Reclassification Adjustment						$ 31
Discontinued Operations [Member] | Product Warranty Accrual [Member]
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Adjustments to pre-existing warranties(A)(B)			$ 2