Revenue - Performance Obligations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-02-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected revenue	$ 23		$ 23
Expected revenue, period	9 months		9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-11-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected revenue	$ 82		$ 82
Expected revenue, period	1 year		1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-11-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected revenue	$ 68		$ 68
Expected revenue, period	1 year		1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-11-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected revenue	$ 47		$ 47
Expected revenue, period	1 year		1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-11-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected revenue	$ 26		$ 26
Expected revenue, period	1 year		1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-11-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected revenue	$ 27		$ 27
Expected revenue, period	1 year		1 year
Extended Warranty Programs [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 27	$ 24	$ 85	$ 80