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, 2018	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2017
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Earnings on Derivative	$ 29	$ 4	$ (11)	$ (48)
Gain (Loss) Recognized on Related Hedged Item	$ (29)	$ (4)	$ 11	$ 48