Segment Reporting - Summary of Segment Long Lived Assets and Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales and revenues, net	$ 1,925	$ 2,996	$ 3,763	$ 5,429
Financial Services Operations
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales and revenues, net	$ 50	$ 48	$ 96	$ 95