Taxes on Earnings (Detail 7) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Carryforward
U.S. foreign tax credits	$ 1,832								$ 1,832
U.S. research and development and other credits	122								122
Tax credits in state and foreign jurisdictions	158								158
Balance at end of year	2,112								2,112
Valuation Allowance
U.S. foreign tax credits	(687)								(687)
Tax credits in state and foreign jurisdictions	(124)								(124)
Balance at end of year	(811)								(811)
Valuation allowance balance
Balance at beginning of year				$ 2,789					2,789
Income tax expense	(1,348)	$ (13)	$ 966	2,139	$ 679	$ 160	$ (591)	$ (84)	1,744	$ 164	$ (623)
Balance at end of year	8,209				2,789				8,209	2,789
Increase (decrease) in valuation allowances									5,400	694
Deferred tax asset valuation allowance
Valuation allowance balance
Balance at beginning of year				$ 2,789				$ 2,095	2,789	2,095	1,572
Income tax expense									(166)	848	(203)
Income tax expense related to the Tax Act									687	0	0
Valuation allowance offsetting current year losses recorded									5,028	0	0
Other comprehensive income, currency translation and charges to other accounts									(129)	(154)	726
Balance at end of year	$ 8,209				$ 2,789				$ 8,209	$ 2,789	$ 2,095