Restructuring and Other Charges - Narrative (Details) employee in Thousands, $ in Millions		3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) employee	Jul. 31, 2021 USD ($)	Jul. 31, 2020 USD ($)	Jul. 31, 2021 USD ($)	Jul. 31, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Other charges		$ 8	$ 13	$ 17	$ 100
Fiscal 2020 Plan
Restructuring Cost and Reserve [Line Items]
Estimated pre-tax charges	$ 1,000
Minimum | Fiscal 2020 Plan
Restructuring Cost and Reserve [Line Items]
Expected positions to be eliminated | employee	7
Maximum | Fiscal 2020 Plan
Restructuring Cost and Reserve [Line Items]
Expected positions to be eliminated | employee	9
Severance and EER | Fiscal 2020 Plan
Restructuring Cost and Reserve [Line Items]
Estimated pre-tax charges	$ 800