Restructuring and Other Charges - Summary of Cost Saving Plan Activities (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Apr. 30, 2020	Apr. 30, 2020	Apr. 30, 2019
Restructuring Reserve [Roll Forward]
Accrued balance, beginning of the period		$ 142	$ 59
Charges	$ 28	285	116
Cash payments		(247)	(72)
Non-cash and other adjustments		(52)	(14)
Accrued balance, beginning of the period	128	128	89
Total costs incurred to date as of April 30, 2020	2,183	2,183
Reflected in Consolidated Condensed Balance Sheets
Other current liabilities	128	128
Fiscal 2020 Plan | Severance and EER
Restructuring Reserve [Roll Forward]
Accrued balance, beginning of the period		76	0
Charges	26	282	0
Cash payments		(205)	0
Non-cash and other adjustments		(49)	0
Accrued balance, beginning of the period	104	104	0
Total costs incurred to date as of April 30, 2020	364	364
Reflected in Consolidated Condensed Balance Sheets
Other current liabilities	104	104
Fiscal 2020 Plan | Non-labor
Restructuring Reserve [Roll Forward]
Accrued balance, beginning of the period		0	0
Charges	2	2	0
Cash payments		(2)	0
Non-cash and other adjustments		0	0
Accrued balance, beginning of the period	0	0	0
Total costs incurred to date as of April 30, 2020	2	2
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	116
Cash payments		(40)	(72)
Non-cash and other adjustments		(3)	(14)
Accrued balance, beginning of the period	24	24	$ 89
Total costs incurred to date as of April 30, 2020	1,817	1,817
Reflected in Consolidated Condensed Balance Sheets
Other current liabilities	$ 24	$ 24