v3.10.0.1
Taxes on Earnings - Narrative (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Oct. 31, 2017
Income Tax Examination [Line Items]          
Effective tax rate (as a percent) 2.80% (128.00%) 1003.90% 89.90%  
Net income tax charges (benefits) $ (68) $ (290) $ (3,300) $ 236  
Release of non-U.S. valuation allowances on deferred tax assets 38   38    
Income tax benefits from U.S. tax reform 33   713    
Net excess tax benefits related to stock compensation 26   68    
Income tax benefit on restructuring charges, separation costs, transformation costs and acquisition and other related charges   61 74 129  
Pre-Separation tax matters 7   2,000    
Foreign tax credit     228    
Benefit from liquidation of business     $ 203    
U.S. provision-to-return adjustments   29   29  
Accrued divestiture tax   189   189  
Tax indemnification   26   57  
Valuation allowance       473  
Reduction resulting from lapse of applicable statute of limitations   $ 25   25  
Federal statutory rate (as a percent)     23.30%    
Transition tax     $ 1,100    
Provisional tax benefit from Tax Cut and Jobs Act     1,800    
Unrecognized tax benefits 8,700   8,700   $ 11,300
Unrecognized tax benefits that would affect effective tax rate if realized 1,100   1,100   3,000
Decrease from settlements with IRS     2,600    
Accrued income tax for interest and penalties 179   $ 179   $ 304
Likelihood of no resolution period     12 months    
Reasonably possible reduction in existing unrecognized tax benefits within the next 12 months $ 85   $ 85    
Likelihood of conclusion period for certain federal, foreign and state tax issues     12 months    
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | Everett SpinCo          
Income Tax Examination [Line Items]          
Net income tax charges (benefits)       $ (79)