Stockholders' Equity-Components (Details) $ in Millions	6 Months Ended
	Apr. 30, 2016 USD ($)
Components of accumulated other comprehensive income, net of taxes
Balance at beginning of period	$ 27,768
Balance at end of period	(4,786)
Change in 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 before reclassifications	1
Balance at end of period	12
Change in 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 before reclassifications	11
Reclassifications of (gains) losses into earnings	(73)
Balance at end of period	(169)
Change in 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 before reclassifications	(2)
Reclassifications of (gains) losses into earnings	18
Balance at end of period	(1,109)
Change in cumulative translation adjustment
Components of accumulated other comprehensive income, net of taxes
Balance at beginning of period	(974)
Separation of Hewlett Packard Enterprise	974
Accumulated Other Comprehensive (Loss) Income
Components of accumulated other comprehensive income, net of taxes
Balance at beginning of period	(6,302)
Separation of Hewlett Packard Enterprise	5,081
Other comprehensive income before reclassifications	10
Reclassifications of (gains) losses into earnings	(55)
Balance at end of period	$ (1,266)