Stockholders' Equity - Narrative (Details) - USD ($) shares in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015	Jul. 21, 2011
Stockholders' Equity Note [Abstract]
Repurchases of common stock (shares)	4.0	11.0	100.0	65.0
Share repurchases that will be settled in subsequent period (shares)	0.2
Payment in connection with repurchases of shares	$ 100,000,000	$ 400,000,000	$ 1,159,000,000	$ 2,582,000,000
Share repurchase authorization remaining	$ 800,000,000		$ 800,000,000
Share repurchase authorization approved					$ 10,000,000,000.0