Financial Instruments - Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	9 Months Ended
	Jul. 31, 2018	Oct. 31, 2017
Derivative assets
Gross Amount Recognized	$ 329	$ 260
Gross Amount Offset	0	0
Net Amount Presented	329	260
Gross Amounts Not Offset
Derivatives	160	209
Financial Collateral	104	34
Net Amount	65	17
Derivative liabilities
Gross Amount Recognized	501	477
Gross Amount Offset	0	0
Net Amount Presented	501	477
Gross Amounts Not Offset
Derivatives	160	209
Financial Collateral	254	242
Net Amount	$ 87	26
Business days prior to reporting date	2 days
Cash collateral	$ 205	220
Counterparty collateral	$ 49	$ 22