Stock-Based Compensation - Schedule of stock Based Compensation Expense and the Resulting Tax Benefits from Continuing Operations (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Jul. 31, 2016	Jan. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense	$ 39		$ 58	$ 140	$ 168
Income tax benefit	(13)		(17)	(48)	(49)
Stock-based compensation expense, net of tax	$ 26		$ 41	$ 92	$ 119
Pre-tax stock-based compensation expense		$ 2