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, 2025	Apr. 30, 2024	Apr. 30, 2025	Apr. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income/(expense) line items in the statement of financial performance in which the effects of fair value hedges are recorded	$ (148)	$ (155)	$ (289)	$ (297)
Gain/(loss) recognized in earnings on derivative instruments	8	0	15	15
Gain/(loss) recognized in earnings on hedged item	$ (8)	$ 0	$ (15)	$ (15)