Summary of Significant Accounting Policies - Product Warranty Liability (Details) - USD ($) $ in Millions	3 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Oct. 31, 2017	Oct. 31, 2016
Product Liability Contingency [Line Items]
Document Type	10-Q
Product Warranty Accrual	$ 573	$ 751	$ 629	$ 818
Product Warranty Accrual, Warranties Issued	29	45
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Adjustments to pre-existing warranties(A)(B)	(6)	(17)
Extended Warranty Program:
Product Warranty Accrual, Payments	(79)	(95)
Product Warranty Accrual, Current	287	371
Product Warranty Accrual, Noncurrent	286	380
Extended Warranty Programs [Member]
Extended Warranty Program:
Deferred Revenue, Revenue Recognized	29	$ 34
Deferred Revenue	$ 256		$ 271