Taxes on Earnings - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Oct. 31, 2017
Income Tax Disclosure [Abstract]
Effective tax rate (as a percent)	325.60%	25.10%
Net income tax charges (benefits)	$ (2,200)	$ (31)
Pre-Separation tax matters	920
Income tax benefits from U.S. tax reform	806
Benefit from liquidation of business	203
Foreign tax credit	244
Income tax benefit on restructuring charges, separation costs, transformation costs and acquisition and other related charges	44	32
Net excess tax benefits related to stock compensation	14
Benefit from change in uncertain tax positions and provision-to-return adjustments		14
Tax indemnification		$ 19
Transition tax	967
Income tax benefit	1,800
Unrecognized tax benefits	10,400		$ 11,300
Unrecognized tax benefits that would affect effective tax rate if realized	2,700		3,000
Decrease from settlements with IRS	900
Accrued income tax for interest and penalties	$ 293		$ 304
Likelihood of no resolution period	12 months
Reasonably possible reduction in existing unrecognized tax benefits within the next 12 months	$ 1,500
Likelihood of conclusion period for certain federal, foreign and state tax issues	12 months