Financial Instruments - Schedule of Pre-Tax Effect of Derivative Instruments and Related Hedged Items in a Fair Value Hedging Relationship (Details) - Interest rate contracts - Interest and other, net - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Earnings on Derivative	$ 4	$ 4	$ (48)	$ 18
Gain (Loss) Recognized on Related Hedged Item	$ (4)	$ (4)	$ 48	$ (18)