Stockholders' Deficit - Narrative (Details) - USD ($) shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
	Jun. 19, 2018	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017
Stockholders' Equity Note [Abstract]
Repurchases of common stock (shares)		31.0	16.0	86.0	55.0
Payment in connection with repurchases of shares		$ 700	$ 300	$ 1,959	$ 911
Share repurchases that will be settled in subsequent period (shares)		0.8	0.4
Share repurchase increase in authorization	$ 4,000
Share repurchase authorization remaining		$ 4,500		$ 4,500