Supplementary Financial Information - Disaggregation of revenue (Details) - USD ($) $ in Millions	3 Months Ended						6 Months Ended		9 Months Ended
	Jul. 31, 2023	Apr. 30, 2023	Jan. 31, 2023	Jul. 31, 2022	Apr. 30, 2022	Jan. 31, 2022	Apr. 30, 2023	Apr. 30, 2022	Jul. 31, 2023	Jul. 31, 2022
Disaggregation of Revenue [Line Items]
Total net revenue	$ 13,196	$ 12,907	$ 13,798	$ 14,648	$ 16,475	$ 17,013	$ 26,705	$ 33,488	$ 39,901	$ 48,136
Americas
Disaggregation of Revenue [Line Items]
Total net revenue	5,880			6,379					17,052	20,111
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total net revenue	4,285			4,712					13,330	16,670
Asia-Pacific and Japan
Disaggregation of Revenue [Line Items]
Total net revenue	$ 3,031			$ 3,557					$ 9,519	$ 11,355