Summary of Significant Accounting Policies - Product Warranty Liability (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			9 Months Ended		3 Months Ended		9 Months Ended			3 Months Ended							9 Months Ended
	Jul. 31, 2014	Apr. 30, 2013	Jan. 31, 2013	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014 Extended Warranty Programs [Member]	Jul. 31, 2013 Extended Warranty Programs [Member]	Jul. 31, 2014 Extended Warranty Programs [Member]	Jul. 31, 2013 Extended Warranty Programs [Member]	Oct. 31, 2013 Extended Warranty Programs [Member]	Jul. 31, 2014 Product Warranty Accrual [Member]	Apr. 30, 2014 Product Warranty Accrual [Member]	Jan. 31, 2014 Product Warranty Accrual [Member]	Jul. 31, 2013 Product Warranty Accrual [Member]	Apr. 30, 2013 Product Warranty Accrual [Member]	Jan. 31, 2013 Product Warranty Accrual [Member]	Jan. 31, 2013 recoverable [Member]	Jul. 31, 2014 Product Warranty Accrual [Member]
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Balance at beginning of period			$ 1,118	$ 1,349	$ 1,118
Costs accrued and revenues deferred				235	342
Product Warranty Accrual, Divestures				0	(3)
Currency translation adjustment				(2)	(3)
Adjustments to pre-existing warranties(A)(B)	(59)			65	252						(29)	42	52	48	164	40	13	30
Payments and revenues recognized				(391)	(484)
Balance at end of period	1,256			1,256	1,222
Less: Current portion	578			578	618
Noncurrent accrued product warranty and deferred warranty revenue	678			678	604
Product Warranty Accrual, Preexisting Increase Decrease Per Share, Net of Tax											$ (0.36)	$ 0.52	$ 0.64	$ 0.60	$ 2.04	$ 0.50
Warranty Recoveries		13	27
Extended Warranty Program:
Deferred Revenue, Revenue Recognized						36	23	96	63
Deferred Revenue						$ 437		$ 437		$ 420