Financial Instruments - Schedule of Information Related to the Potential Effect of Entity's Master Netting Agreements and Collateral Security Agreements (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Jul. 31, 2017	Oct. 31, 2016
Derivative assets
Gross Amount Recognized	$ 66	$ 325
Gross Amount Offset	0	0
Net Amount Presented	66	325
Gross Amounts Not Offset
Derivatives	63	88
Financial Collateral	0	189
Net Amount	3	48
Derivative liabilities
Gross Amount Recognized	658	97
Gross Amount Offset	0	0
Net Amount Presented	658	97
Gross Amounts Not Offset
Derivatives	63	88
Financial Collateral	519	2
Net Amount	$ 76	$ 7
Period to collateralize	2 days	2 days