Restructuring and Other Charges - Summary of Cost Saving Plan Activities (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jul. 31, 2020	Jul. 31, 2020	Jul. 31, 2019
Restructuring Reserve [Roll Forward]
Accrued balance, beginning of the period		$ 142	$ 59
Charges	$ 46	331	130
Cash payments		(309)	(112)
Non-cash and other adjustments		(51)	(15)
Accrued balance, beginning of the period	113	113	62
Total costs incurred to date as of July 31, 2020	2,229	2,229
Reflected in Consolidated Condensed Balance Sheets
Other current liabilities	113	113
Fiscal 2020 Plan | Severance and EER
Restructuring Reserve [Roll Forward]
Accrued balance, beginning of the period		76	0
Charges	43	325	0
Cash payments		(256)	0
Non-cash and other adjustments		(48)	0
Accrued balance, beginning of the period	97	97	0
Total costs incurred to date as of July 31, 2020	407	407
Reflected in Consolidated Condensed Balance Sheets
Other current liabilities	97	97
Fiscal 2020 Plan | Non-labor
Restructuring Reserve [Roll Forward]
Accrued balance, beginning of the period		0	0
Charges	3	5	0
Cash payments		(5)	0
Non-cash and other adjustments		0	0
Accrued balance, beginning of the period	0	0	0
Total costs incurred to date as of July 31, 2020	5	5
Reflected in Consolidated Condensed Balance Sheets
Other current liabilities	0	0
Fiscal 2020 Plan | Healthcare and medical savings account benefits
Restructuring Reserve [Roll Forward]
Non-cash and other adjustments		44
Other prior-year Plans
Restructuring Reserve [Roll Forward]
Accrued balance, beginning of the period		66	59
Charges	0	1	130
Cash payments		(48)	(112)
Non-cash and other adjustments		(3)	(15)
Accrued balance, beginning of the period	16	16	$ 62
Total costs incurred to date as of July 31, 2020	1,817	1,817
Reflected in Consolidated Condensed Balance Sheets
Other current liabilities	$ 16	$ 16