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
	Jul. 31, 2018	Oct. 31, 2017
Derivative assets
Gross Amount Recognized	$ 323	$ 121
Gross Amount Offset	0	0
Net Amount Presented	323	121
Gross Amounts Not Offset
Derivatives	104	108
Financial Collateral	186	4
Net Amount	33	9
Derivative liabilities
Gross Amount Recognized	215	372
Gross Amount Offset	0	0
Net Amount Presented	215	372
Gross Amounts Not Offset
Derivatives	104	108
Financial Collateral	91	219
Net Amount	$ 20	$ 45
Period to collateralize	2 days