Stockholders' Equity - Schedule of Accumulated Other Comprehensive Loss, Net of Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Components of accumulated other comprehensive income, net of taxes
Balance at beginning of period			$ 27,768
Separation of Hewlett Packard Enterprise			5,081
Other comprehensive income (loss) before reclassifications			181
Reclassifications of losses into earnings			93
Balance at end of period	$ (3,926)		(3,926)
Net unrealized gains (losses) on available-for-sale securities
Components of accumulated other comprehensive income, net of taxes
Balance at beginning of period			66
Separation of Hewlett Packard Enterprise			(55)
Other comprehensive income (loss) before reclassifications	1	$ 1	2	$ (9)
Reclassifications of losses into earnings			0
Balance at end of period	13		13
Net unrealized (losses) gains on cash flow hedges
Components of accumulated other comprehensive income, net of taxes
Balance at beginning of period			(39)
Separation of Hewlett Packard Enterprise			(68)
Other comprehensive income (loss) before reclassifications	170	203	181	635
Reclassifications of losses into earnings	139	$ (111)	66	$ (746)
Balance at end of period	140		140
Unrealized components of defined benefit plans
Components of accumulated other comprehensive income, net of taxes
Balance at beginning of period			(5,355)
Separation of Hewlett Packard Enterprise			4,230
Other comprehensive income (loss) before reclassifications			(2)
Reclassifications of losses into earnings			27
Balance at end of period	(1,100)		(1,100)
Cumulative translation adjustment
Components of accumulated other comprehensive income, net of taxes
Balance at beginning of period			(974)
Separation of Hewlett Packard Enterprise			974
Other comprehensive income (loss) before reclassifications			0
Reclassifications of losses into earnings			0
Balance at end of period	0		0
Accumulated other comprehensive (loss) income
Components of accumulated other comprehensive income, net of taxes
Balance at beginning of period			(6,302)
Balance at end of period	$ (947)		$ (947)