Supplementary Financial Information - Net Revenue by Region (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue	$ 56,639	$ 58,756	$ 58,472
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue	24,414	25,244	25,644
Europe, Middle East and Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue	19,624	20,275	20,470
Asia-Pacific and Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue	$ 12,601	$ 13,237	$ 12,358