Financial Instruments - Schedule of Information Related to the Potential Effect of Entity's Master Netting Agreements and Collateral Security Agreements (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Apr. 30, 2017	Oct. 31, 2016
Derivative assets
Gross Amount Recognized	$ 134	$ 325
Gross Amount Offset	0	0
Net Amount Presented	134	325
Gross Amounts Not Offset
Derivatives	127	88
Financial Collateral	0	189
Net Amount	7	48
Derivative liabilities
Gross Amount Recognized	278	97
Gross Amount Offset	0	0
Net Amount Presented	278	97
Gross Amounts Not Offset
Derivatives	127	88
Financial Collateral	133	2
Net Amount	$ 18	$ 7
Period to collateralize	2 days	2 days